Transfer device for orthodontic appliances and related manufacturing methods

Abstract

A method for making a transfer device includes providing a physical mock-up having a shape corresponding to the positive shape of a patient's dental arch and one or more carrier assemblies, each including a crane body releasably connected to an orthodontic appliance. The transfer device may be formed over the physical mock-up, and a transfer tray represents a negative replica of at least a portion of the mock-up. The transfer device may be used to seat the appliance on the patient's dental arch, after which the appliance can be separated from the crane body and bonded to the associated tooth.

Description

[Technical Field]

[0001] Orthodontic appliances are used in orthodontic treatment to move one or more teeth from an initial position (sometimes called a malposition or malocclusion) in a patient's dentition to a desired position. For example, a patient's teeth may be moved so that their labial sides are aligned with one another to achieve or maximize an aesthetically pleasing appearance for the entire dentition. Additionally, in some cases, one or more teeth may be moved to correct a malocclusion. Tooth movement is typically achieved in traditional orthodontic braces with a pre-biased archwire that is attached to the teeth via brackets and applies a force to the teeth toward a desired position over time. The ends of the orthodontic archwire are often connected to small appliances known as buccal tubes that are secured to the patient's molars. Often, a set of brackets, buccal tubes, and archwire is provided for each of the upper and lower dental arches.

[0002] Orthodontic treatment may also include the use of alignment trays, such as clear or transparent polymer-based tooth-positioning trays, often referred to as clear tray aligners (CTAs). For example, orthodontic treatment with a CTA may include forming a tray having shells that engage one or more teeth. Each shell can be deformed from an initial position of the teeth, e.g., a malocclusion position. The deformed position of each shell of the CTA can apply a force to each tooth toward a desired position of the tooth that is an intermediate position between the initial position and the final position resulting from orthodontic treatment.

[0003] In some embodiments, small attachments may be bonded to teeth to improve force application or achieve desired tooth movement. In many types of orthodontic techniques, the precise positioning of appliances, be they attachments or brackets, relative to the teeth is a critical factor in helping ensure that the teeth move to their intended final positions. Proper placement of the attachment can ensure proper engagement and interaction between the attachment and one or more CTAs. The design of the attachment can provide the desired physical leverage to generate the desired force against the teeth to produce specific tooth movement during treatment. Attachments are typically constructed of various materials, shapes, and sizes and can be bonded to the labial or lingual surfaces of the teeth to interact with CTAs and removable appliances in a variety of different ways. Attachments can be applied to the patient's teeth prior to treatment with aligners. Attachments may be manufactured before being attached to the tooth surfaces. Attachments may also be substantially assembled in the orthodontic practitioner's office prior to or in conjunction with placement on the patient's teeth (e.g., molded composites, etc.).

[0004] Generally, bondable orthodontic appliances can be attached to teeth by direct or indirect bonding. In direct bonding, the appliances are typically grasped with a pair of tweezers or other manual instruments and positioned by the practitioner in the desired location on the tooth surface using an amount of adhesive that secures the appliance to the tooth. In indirect bonding, a transfer tray is constructed with wall sections shaped to fit the anatomy of at least a portion of the patient's dental arch, and appliances, such as orthodontic attachments, are removably connected to the tray at certain predetermined locations. After adhesive is applied to the base of each appliance, the tray is placed over the patient's teeth and remains in place until the adhesive hardens. The tray is then removed from the teeth and appliances, allowing the appliances previously connected to the tray to be bonded to their intended positions on their respective teeth.

[0005] Indirect bonding techniques offer several advantages over direct bonding techniques. For example, using indirect bonding techniques, multiple appliances can be bonded to a patient's dental arches simultaneously, thereby avoiding the need to bond each appliance individually. Additionally or alternatively, transfer trays may improve the accuracy of attachment placement. In many cases, the improved accuracy of appliance placement afforded by indirect bonding methods helps ensure that a patient's teeth are moved to their proper intended positions upon completion of treatment. Due to their small size and shape, attachments can be difficult to manipulate for placement in transfer trays. Summary of the Invention

[0006] Previous methods for bonding attachments to teeth generally relied on either placing preformed attachments in an indirect bonding tray or molding the attachments directly onto the tooth surface. Both methods introduced various errors into the bonding process, appliance fit, and treatment outcome. Preformed attachments are typically difficult to handle given their relatively small dimensions, making them difficult to place in the tray or directly on the teeth. Failure to properly position them leads to misdirected forces and associated suboptimal engagement with the CTA. Attempts to create transfer devices with attachments result in shapes that are challenging for additive manufacturing and excessive customization challenges that can slow down commercial operations. Molding appliances onto tooth surfaces presents its own challenges, typically centered around the difficulty of ensuring proper bonding to the tooth surface and sufficient material strength in the molded attachment body. The present inventors have sought to solve these and other problems by providing a preformed appliance that can be molded using a transfer device.

[0007] In one aspect, the present disclosure provides a physical mockup for creating a transfer device. The mockup includes a representation of at least a portion of a dental arch, the dental arch including a plurality of teeth, each tooth including an occlusal surface, a lingual surface, and a labial surface, and one or more teeth including a registration pin projecting upward from the occlusal surface. A carrier assembly can be received on each registration pin to assist in positioning the appliance on the tooth surface. The carrier can include a crane including a crane body having a tooth-facing surface, the facing surface configured to not contact the occlusal surface of the tooth when the transfer body is placed on the dental arch; an orthodontic appliance including a base for coupling the appliance to the tooth and a body including a periphery; and one or more linkage arms configured to connect the crane to the appliance, the linkage arms being frangible between the crane and the appliance.

[0008] In another aspect, the present disclosure provides a method for making a transfer tray for one or more orthodontic appliances. The method includes providing a physical mockup including a representation of at least a portion of a dental arch, the dental arch including a plurality of teeth, each tooth including an occlusal surface, a lingual surface, and a labial surface, with one or more teeth including a registration pin projecting upward from the occlusal surface. The method proceeds with placing an appliance carrier over the registration pin for each tooth including the registration pin. The carrier includes: a crane including a crane body having a tooth-facing surface, the facing surface configured to avoid contacting the occlusal surface of the tooth when the transfer body is placed on the dental arch; an orthodontic appliance including a base for coupling the appliance to the tooth and a body including a periphery; and one or more linkage arms configured to connect the crane to the appliance, the linkage arms being frangible between the crane and the appliance. Once the carrier assembly is positioned, the method proceeds with forming a tray over the mockup and carrier.

[0009] In another aspect, the present disclosure provides a system for indirect bonding of orthodontic appliances. The system includes: a transfer body defining a shell configured to receive an outer surface of a tooth in a dental arch and including an inner surface substantially conforming to the contour of at least one tooth in the dental arch, the transfer body defining at least one recess in the shell; and an orthodontic appliance carrier positioned against the occlusal surfaces of the teeth. The carrier includes: a crane including a crane body having a tooth-facing surface configured to avoid contacting the occlusal surfaces of the teeth when the transfer body is placed on the dental arch; an orthodontic appliance including a body having a base for bonding the appliance to the tooth and a periphery; and one or more linkage arms configured to connect the crane to the appliance, the linkage arms being frangible between the crane and the appliance.

[0010] In yet another aspect, the present disclosure provides a carrier for use in bonding orthodontic appliances to a patient's teeth, the carrier comprising: a crane including a crane body having a tooth-facing surface configured to avoid contacting the occlusal surfaces of the teeth when the crane is placed on the dental arch; an orthodontic appliance including a body including a base and a periphery for bonding the appliance to the teeth; and one or more linkage arms configured to connect the crane to the appliance, the linkage arms being frangible between the crane and the appliance.

[0011] For the purposes of this specification, the term "virtual" refers to a three-dimensional computer representation of an object, preferably based on a mathematical representation of the three-dimensional shape that is processable by a computer in the form of data. Such virtual objects in the form of data, including visualizations (e.g., wireframes or digital renderings), are widely known in the field of computer-aided design (CAD).

[0012] For purposes of this specification, the term "set" refers to "plurality."

[0013] As used herein, "orthodontic appliance" includes orthodontic brackets, orthodontic attachments, buccal tubes, orthodontic bands, buttons, and cleats, especially orthodontic brackets and orthodontic attachments.

[0014] As used herein, "hardenable" refers to a material or composition that can be hardened (e.g., polymerized or crosslinked), for example, by removing solvent (e.g., by evaporation and / or heating), by heating to induce polymerization and / or crosslinking, by irradiating to induce polymerization and / or crosslinking, and / or by mixing one or more components to induce polymerization and / or crosslinking. As used herein, "hardened" refers to a material or composition that has been cured (e.g., polymerized or crosslinked) or solidified.

[0015] When used herein as a modifier to a property or attribute, the term "generally," unless otherwise specifically defined, means that the property or attribute is readily recognizable by one of ordinary skill in the art, but does not require absolute precision or perfect agreement (e.g., within + / - 20% for quantifiable properties). The terms "substantially" or "essentially," unless otherwise specifically defined, mean a high degree of approximation (e.g., within + / - 10% for quantifiable properties), but again does not require absolute precision or perfect agreement. Terms such as same, equal, uniform, constant, exactly, etc., are understood to be within normal tolerances or measurement errors applicable to the particular situation, rather than requiring absolute precision or perfect agreement.

[0016] As used herein, "anterior teeth" includes central incisors, lateral incisors, canines, and first premolars.

[0017] As used herein, "back teeth" includes second premolars, first molars, second molars, and third molars (if the patient still retains wisdom teeth).

[0018] The above summary of the present disclosure is not intended to describe each embodiment or every implementation disclosed in the present disclosure. The following description more particularly exemplifies exemplary embodiments. In several places throughout the application, guidance is provided through lists of examples, which examples can be used in various combinations. In each instance, the recited list serves only as a representative group and should not be interpreted as an exclusive list.

[0019] "Mesial" means in a direction toward the center of the patient's curved dental arch.

[0020] "Distal" means in a direction away from the center of the patient's curved dental arch.

[0021] "Occlusal" means in a direction toward the outer tips of the patient's teeth and includes the "incisal edges."

[0022] "Gingival" means in a direction toward the patient's gums or gingiva.

[0023] "Facial" means in a direction toward the patient's cheeks or lips.

[0024] "Lingual" means in a direction toward the patient's tongue.

[0025] In several places throughout the application, guidance is provided through lists of examples, which examples can be used in various combinations. In each instance, the recited list serves only as a representative group and should not be interpreted as an exhaustive list. [Brief explanation of the drawings]

[0026] [Figure 1] FIG. 1 is a perspective view of a physical mockup having a set of carrier assemblies for orthodontic appliances according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a perspective view of the physical mock-up of FIG. 1 enlarged to show half of a dental arch. [Figure 3A]FIG. 1 is a perspective view of an orthodontic appliance in the form of an attachment according to an embodiment of the present disclosure. [Figure 3B] FIG. 10 is a perspective view of another orthodontic appliance in the form of an attachment according to an embodiment of the present disclosure. [Figure 4] FIG. 10 is a perspective view of a fixture model including a mold body and alignment pins according to an embodiment of the present disclosure. [Figure 5] FIG. 5 is an occlusal view of the fixture model of FIG. 4. [Figure 6] FIG. 6 is an enlarged perspective view of the fixture model of FIGS. 4 and 5. [Figure 7] FIG. 3 is a perspective view of a carrier assembly received on alignment pins in the mockup of FIGS. 1 and 2. [Figure 8] 8 is a schematic cross-sectional view of the carrier assembly and alignment pin of FIG. 7. [Figure 9] FIG. 3 is a perspective view of a second carrier assembly received on alignment pins in the mockup of FIGS. 1 and 2. [Figure 10] FIG. 1 is a perspective view of a carrier assembly according to an embodiment of the present disclosure. [Figure 11] FIG. 11 is a perspective view of the carrier assembly of FIG. [Figure 12] FIG. 10 is a perspective view of a carrier assembly according to another embodiment of the present disclosure. [Figure 13] 3 is a workflow for creating a virtual mockup to assist in the creation of the physical mockup of FIGS. 1 and 2. [Figure 14] FIG. 1 is a perspective view of a virtual orthodontic appliance in the form of an attachment according to an embodiment of the present disclosure. [Figure 15] FIG. 1 is a perspective view of a virtual mockup including appliances placed on virtual teeth according to an embodiment of the present disclosure. [Figure 16] FIG. 1 illustrates a perspective view of a virtual crane assembly including a crane body and alignment pins according to an embodiment of the present disclosure. [Figure 17] FIG. 16 is a perspective view of the virtual mockup of FIG. 15 including a crane assembly positioned relative to a coupling tooth. [Figure 18] FIG. 18 is an enlarged perspective view of a crane assembly positioned above an instrument on a mating tooth of the virtual mockup of FIG. 17. [Figure 19] FIG. 19 is an articulated view of the crane assembly and implement of FIG. 18. [Figure 20] FIG. 20 is a schematic cross-sectional view of the crane assembly and implement of FIGS. 18 and 19; [Figure 21] FIG. 1 is a perspective view of a virtual mockup having a set of carrier assemblies for orthodontic appliances according to an embodiment of the present disclosure. [Figure 22] FIG. 1 is a perspective view of a virtual fixture model including a composite dental arch, a mold body, and alignment pins. [Figure 23] 1 is a workflow for assembling a physical mockup including a carrier assembly of the present disclosure. [Figure 24] FIG. 1 is a perspective view of a transfer tray made from the physical mockup of the present disclosure. [Figure 25] FIG. 25 is a cross-sectional view of the transfer tray of FIG. 24. [Figure 26A] FIG. 1 is a perspective view of a carrier assembly according to an embodiment of the present disclosure. [Figure 26B] FIG. 1 is a perspective view of a carrier assembly according to an embodiment of the present disclosure. [Figure 26C] FIG. 1 is a perspective view of a carrier assembly according to an embodiment of the present disclosure. [Figure 27] FIG. 10 is a perspective view of another embodiment of a carrier assembly received on an alignment pin on a tooth in a mockup of the present disclosure. [Figure 28] 28 is a schematic cross-sectional view of the carrier assembly and alignment pin of FIG. 27. [Figure 29] FIG. 10 is a schematic cross-sectional view of another embodiment of an alignment pin and carrier assembly according to the present disclosure. [Figure 30] FIG. 10 is an exploded perspective view of another embodiment of a carrier assembly and associated alignment pins on teeth in a mockup of the present disclosure. [Figure 31] FIG. 31 is a schematic cross-sectional view of the carrier assembly and alignment pin of FIG. 30. DETAILED DESCRIPTION OF THE INVENTION

[0027] While the above-identified Figures set forth several embodiments of the present disclosure, other embodiments are also contemplated, as noted in the description. In all cases, this disclosure presents the invention by way of representation and not limitation. It should be understood that numerous other variations and embodiments can be devised by those skilled in the art and are within the scope and spirit of the principles of the present invention.

[0028] 1 and 2 show a physical mock-up 10 that represents the positive shape of a patient's dental arch 12, including a plurality of teeth 13 and gums 14. The physical mock-up 10 can be used to physically mold a transfer device (not shown in FIGS. 1 or 2) for bonding orthodontic appliances in place on the patient's teeth. The transfer device forms a negative replica of at least a portion of the physical mock-up 10. Such a transfer device (see, e.g., FIG. 24) can be obtained, for example, from taking an impression from the physical mock-up 10, from overmolding the physical mock-up 10, or from any other technique in which the positive physical model 10 is used to mold a negative replica, preferably directly.

[0029] Transfer devices so created from the mockups of the present disclosure can be used to bond orthodontic appliances in predetermined positions and orientations on a patient's dental arch. As used herein, "position" refers to the positioning of the appliance at a particular point on the tooth surface, and "orientation" is the position of the appliance relative to the axis or plane of the mockup or dental arch. Appliances can have changes in orientation that do not change their position on the tooth surface. For example, an appliance can be positioned at a particular point on the tooth surface and then oriented, for example, by rotating it about an axis perpendicular to the tooth surface.

[0030] While the mockups of the present disclosure can be used to create transfer devices for multiple orthodontic appliances (brackets, anchors, buttons, etc.), the appliance 30 shown in FIG. 1 has the shape and function of an orthodontic attachment for CTA. As shown in more detail in FIGS. 3A and 3B , the appliance 30 includes an appliance body 31 ("body 31") configured to be coupled to a tooth to improve the application of force by the CTA to achieve the desired tooth movement. The body 31 may have any suitable shape, such as a custom-formed shape specific to a particular application, patient, tooth, and / or tooth region. The body 31 may be sized such that it is difficult to manipulate the body 31 using a tool such as tweezers. For example, the body 31 may have a maximum dimension of 30 millimeters (mm) or less and a minimum dimension of 0.25 mm or more. For a typical orthodontic attachment, the body 31 may have a maximum dimension of 15 mm or less.

[0031] 3A and 3B, the body 31 has a generally rectangular shape and includes opposed long edges 32, 33. The long edges 32, 33 are joined by short edges 34, 35. Any one of the edges 32, 33, 34, 35 may be concave, convex, straight, or a combination thereof. Each of the long edges 32, 33 may optionally include a concave intermediate portion with a generally straight portion adjacent the short edges 34, 35. The short edges 34, 35 themselves are generally straight, although this is not required.

[0032] The bonding surface 38 of the body 31 may be shaped to correspond to the contours of a portion of a patient's tooth. In one or more embodiments, the bonding surface 38 of one or more appliances 30 may include any suitably shaped surface that is not necessarily customized to fit a particular surface of a tooth, i.e., a "universal" base. The bonding surface 38 may include a compound curvature that corresponds to the expected convex curvature or average convex curvature of a particular tooth in a dental arch. Corresponding to the tooth contour can improve the strength of the adhesive bond between the body 31 and the tooth, reduce the amount of adhesive required for bonding, or both. For example, the bonding surface 38 may be shaped to bond at the clinical coronal axis ("FACC") of a particular tooth in a particular dental arch. The FACC is defined as the curve formed by the intersection of the midsagittal plane and the facial surface of a given tooth. In some examples, the bonding surface 38 may include an etched, sandblasted, and / or embossed pattern intended to facilitate a more secure bond.

[0033] The bonding surface 38 can have a tooth-facing contour customized to fit any suitable surface of a tooth. For example, in one or more embodiments, the bonding surface 38 has a tooth-facing contour customized to fit the labial surface of a given tooth. Having a customized bonding surface 38 can allow the appliance 30 to be constructed with a lower profile for patient comfort. Any suitable technique or combination of techniques can be utilized to form the customized bonding surface, such as, for example, the techniques described in U.S. Pat. No. 10,136,965 (Wiechmann et al.) and U.S. Patent Application Publication No. 2005 / 0277084 (Cinader, Jr. et al.), which involve, for example, Boolean subtraction of virtual teeth from virtual appliance bonding surfaces in CAD or other software.

[0034] The body 31 may include any suitable shape configured to transfer force from the CTA to the tooth, retain the CTA on the tooth, or both. For example, one or more portions of the body 31 may be hemispherical, linear, curved, or irregularly shaped. In some embodiments, any surface of the body 31 may include one or more surface features, including, but not limited to, one or more tapers, undercuts, overhangs, recesses, negative draft angles, or other features configured to engage or otherwise interact with the CTA or transfer tray. As shown in FIG. 3B , the body 31 may define a sloped buccal / lingual surface 39. In some embodiments, the sloped body 31 may improve release of the body 31 from the transfer tray after bonding to the tooth and / or improve force transfer from the CTA to the tooth by concentrating contact between the CTA and the body 31 at the apex of the slope, or provide a lead-in for engagement when there is a misalignment between the CTA and the tooth.

[0035] The appliance 30 also includes a major axis 40 (i.e., longitudinal axis) and a central axis 42 that is perpendicular to the major axis 40 and extends through both the bonding surface 38 and the opposing surface 39. The axes 40, 42 extend through the approximate center of the appliance, which may be both a mesial-distal center and an occlusal-gingival center, although the exact identity depends on the orientation of the appliance 30 on the bonding surface. The major axis 40 extends between the short edges 34, 35. Both the major axis 40 and the central axis 42 can be useful in certain embodiments for placing the appliance 30 in a desired position and orientation on the teeth, as well as for indicating certain aspects of the physical mock-up 10, as discussed further below.

[0036] 1 and 2, mockup 10 includes a support (i.e., mold body) 15 that extends below the gums 14 to provide stability to facilitate easier creation of the mockup and subsequent fabrication of the transfer device. The bottom of the mold body is typically substantially planar, forming a ground plane "B." The mockup further includes a vertical axis "V" that is perpendicular to the occlusal plane of the dental arch, which can be determined using techniques known in the art and described further below. While vertical axis V may be perpendicular to ground plane B at some locations along arch 12, this is neither typical nor necessary.

[0037] In the physical mockup 10, the patient's teeth 13 are represented in a malocclusion at the beginning of either treatment or a new treatment phase. While the exemplary mockup 10 shown in the drawings represents the patient's upper dental arch, it should be understood that the methods and systems of the present disclosure are equally suitable for the patient's lower dental arch. While the entire upper dental arch 12 is shown in FIG. 1 , for clarity of illustration, half of the arch is shown in FIG. 2 . Referring to the half-arch of FIG. 2 , the teeth 13 in the mockup 10 include an upper central incisor 13 a, an upper lateral incisor 13 b, an upper canine 13 c, an upper first premolar 13 d, an upper second premolar 13 e, an upper first molar 13 f, and an upper second molar 13 g. Alternatively, the physical mockup may include an entire dental arch ( FIG. 1 ) or a smaller portion thereof (e.g., an arch quadrant or a single tooth, not shown), depending on the number of appliances intended to be bonded to the teeth during a given bonding procedure.

[0038] An orthodontic appliance carrier assembly 100 is positioned adjacent the occlusal surface 16 of each tooth 13 to which an orthodontic appliance 30 will be bonded. Each carrier 100 is configured to position an associated appliance 30 in a prescribed or otherwise intended bonding position and orientation proximate a mockup tooth surface (here, the labial tooth surface 17). Each carrier 100 is connected to the associated appliance 30 via one or more linking arms 120 that project generally gingivally from a crane body 102 of the carrier 100. Also, as shown, each tooth 13 in the dental arch 12, with the exception of the second molars, upper central incisors, and maxillary teeth, which are bonded to all of the teeth 13 in the dental arch 12, may receive an appliance 30, or it may be attached to only certain selected teeth, as may be desired by the practitioner or prescribed according to an orthodontic treatment plan. Each appliance 30 on the physical mockup 10 is precisely positioned on the appliance-bonding surface 17 of a tooth 13 and oriented so that it can provide a desired force to the patient's tooth when combined with another dental appliance (e.g., a CTA) or appliance component (e.g., an archwire or polymer band).

[0039] The mockup 10 of this embodiment and the appliances of other embodiments are described herein using a reference frame attached to the labial surfaces of the teeth on the upper jaw, unless otherwise indicated. Accordingly, terms such as labial, lingual, mesial, distal, occlusal, and gingival used to describe the mockup 10, carrier assembly 100, and appliance 30 are relative to the selected reference frame. However, the embodiments are not limited to the selected reference frame and descriptive terminology, as the appliance 30 may be used on other tooth surfaces and in other orientations within the oral cavity. For example, the carrier assembly may be positioned to position the appliance adjacent to the lingual surfaces of the teeth or to position the appliance on both the lingual and labial tooth surfaces. Those skilled in the art will recognize that the descriptive terminology used herein may not directly apply when there is a change in the reference frame. Nevertheless, the embodiments are intended to be independent of absolute position and orientation within the oral cavity, and the relative terminology used to describe the embodiments is merely to provide a clearer description of the embodiments in the drawings. In the remainder of this application, appliance bonding surfaces include labial surfaces, lingual surfaces, and occlusal surfaces (eg, occlusal stop surfaces), but are referred to as labial surfaces.

[0040] In the presently preferred embodiment, the crane body 102 does not contact or include the contoured surface of the associated occlusal tooth surface 16. Instead, each carrier assembly 100 is releasably associated with (i.e., received on or within) a registration pin 200 (visible on the upper canine 13c and shown in more detail in FIGS. 4-6) that includes geometric and / or mating features that help prevent movement of the crane body 102 before contact with the occlusal surface 16. In this manner, by eliminating the need for intimate occlusal contact, aspects of the carrier assembly 100 and registration pin 200, discussed further below, can be standardized to improve manufacturing efficiency and bonding accuracy when fabricating transfer devices (e.g., trays) using the mockups of the present disclosure.

[0041] 4-6 show the mockup 10 without the associated carrier assembly 100. The combination of the dental arch 12, mold body 15, and alignment pins 200 may hereinafter be referred to as the fixture model. The alignment pins 200 project upward from the occlusal surface 16 of each tooth 13 (hereinafter, bonded teeth) to which the orthodontic appliance 30 will be bonded. In the presently preferred embodiment, each alignment pin 200 projects vertically outward from the associated occlusal surface 16 aligned with a vertical axis 201 perpendicular to the base plane B of the mold body 15. Alternatively, one or more alignment pins 200 may include a vertical axis 201 aligned with the vertical axis V. Either orientation can advantageously allow the carrier assembly 100 to be easily placed on the alignment pins 200, allowing the subsequently formed transfer device to be more easily removed from the mockup 10. However, in the presently preferred situation, the axes 201 are aligned substantially perpendicular to the ground plane B, with each perpendicular axis 201 of each alignment pin in the mockup 10 being essentially parallel to all other perpendicular axes 201.

[0042] The alignment pin 200 includes a body 202, a head 210, and a shoulder 220 located at the base 212 of the head 210, closer to the occlusal surface 16. The head 210 may generally be conical, frustoconical, pyramidal, frustopyramidal, or any other suitable shape that limits rotation about a vertical axis. The rotation-limiting shape may include one or more facets (e.g., half-moon, cloverleaf, etc.) that, alone or in combination, inhibit rotation. In some embodiments, the head 210 includes a taper that decreases in cross-sectional dimension between the base 212 and the apex 214 of the head 210. For example, the head may include one or more side surfaces with a negative draft angle of at least 5 degrees and no more than 15 degrees, providing one or more beveled surfaces 216. The presence of beveled surfaces on the head can aid in placement of the carrier assembly onto the alignment pin 200 and removal of the transfer device from the mockup 10. In other embodiments, the head has a substantially continuous cross-sectional dimension.

[0043] Different degrees of inclination of the faces on the head 210 can produce a head axis 211 that is not aligned with the vertical axis V or the body 202. In an alternative embodiment, as shown in FIG. 29 , the vertical axis 211 of the head portion 210 of one or more alignment pins 200 can be inclined relative to the vertical axis V and / or the vertical axis 201. The head portion 210 in the embodiment of FIG. 29 includes an essentially vertical head surface 216 b, with an opposing inclined surface 216 a that is angled more than the inclined surfaces 216 in the other illustrated embodiments. Providing an essentially vertical surface can enhance retention of the carrier assembly 100 on the model 10 in certain circumstances.

[0044] The body 202 has a generally rectangular cross-section that matches the cross-sectional shape of the head 210. The body 202 at the shoulder 220 has a larger cross-sectional dimension than the head 210 and provides an occlusal stop surface adjacent the base 212. The shoulder 220 is positioned at a predetermined height from the occlusal surface 16 of the bonding tooth 13. The height is determined so that the shoulder rests comfortably above the occlusal surface 16 in the z-direction. In this manner, the shoulder 220 prevents vertical movement of the carrier assembly 100 and the crane body 102 does not contact the occlusal surface 16. When vertical movement is stopped along the axis 201, the appliance 30 is typically positioned at a defined bonding position and orientation on the bonding tooth surface. In certain embodiments, the occlusal stop surface / shoulder 220 has a height of at least about 0.2 mm, and in some embodiments, at least about 0.3 mm. A shorter height may promote undesirable occlusal contact in certain circumstances, while a higher height may require a longer connecting arm 120 and a larger transfer device, which may lead to unintended breakage or patient discomfort.

[0045] In a presently preferred embodiment, the alignment pin 200 is positioned adjacent to the instrument mating surface in a position such that the vertical axis 201 is aligned generally perpendicular to the central axis 42 of the associated instrument 30 when the instrument 30 is placed on the mockup 10. In such an embodiment, the edge of the body 202 is oriented substantially parallel to the instrument's longitudinal axis 40 and / or substantially perpendicular to the central axis 42 (see FIG. 5 ). The alignment pin's vertical axis 201 is spaced from the instrument mating surface a sufficient distance to reliably remove the instrument 30 and carrier assembly 100 from the mockup 10. For example, the distance between the vertical axis and a plane tangent to the mating surface is approximately 1.8 mm.

[0046] The shape and cross-sectional dimensions of the alignment pin 200 may be the same for each bonded tooth, allowing for improved standardization of manufacturing and assembly. In other embodiments, at least one of the vertical axis, shape, and cross-sectional dimensions may be modified to allow for correspondence between a given carrier assembly and a particular bonded tooth. For example, a conical head 210 may indicate correspondence with carrier assemblies for anterior teeth, while a truncated pyramidal assembly indicates correspondence with carrier assemblies for posterior teeth. Alternatively or additionally, the alignment pin or surrounding tooth surface may include indicia identifying the associated carrier assembly. The indicia may include text, symbols, colors, score lines, etc.

[0047] Another indicator for appliance / carrier assembly placement can be found on the appliance bonding surface in FIG. 6 . The intended placement location for the appliance 30 can include a recess 50 shaped to receive the appliance in a predetermined position and orientation. The recess 50 has a boundary 52 that substantially matches the shape of the bonding surface 38 of the associated appliance 30. The recess 50 is recessed from the surrounding bonding surface of the tooth 13. In an exemplary embodiment, the recess 50 is recessed approximately 100 microns from the surrounding bonding surface. The recess 50 aids in both locating the appliance 30 on the mockup 10 and reducing or eliminating excess gaps between the appliance and the tooth when the appliance is seated in the patient's mouth, improving bonding to the tooth surface. The recess 50 can also provide improved alignment with the bonding surface 38 as well as indicate the proper orientation of the appliance to the person assembling the mockup. The recess 50 can also help position the bonding surface 38 closer to the tooth than the walls of the transfer device, ensuring that the transfer device does not interfere with appliance bonding at the bonding site. In the same or other embodiments, the recess 50 can provide space for receiving the compressible material prior to placement of the associated carrier assembly so that the compressible material can later be secured to the bonding surface 38.

[0048] 7 and 8, the carrier assembly 100 and the alignment pin 200 on the upper canine tooth 13c are shown in more detail. The carrier assembly 100 includes a crane body 102 having a generally polygonal cross-sectional shape when viewed in a direction along the occlusal plane. The crane body 102 is received over the head 210 of the alignment pin 200. The body 102 includes first and second inclined surfaces 103, 104 that meet at an apex 105. A tooth-facing surface 106 is located opposite the apex 105, and opposing side surfaces 107, 108 extend between the facing surface 106 and the apex 105. As shown, the tooth-facing surface 106 is substantially planar, although the facing surface 106 may also be concave, convex, or include a compound curvature. The transition between any two adjacent surfaces (e.g., first angled surface 103 and side surface 107) is typically arcuate with a defined curvature so that crane body 102 lacks sharp edges. The transition can be of various radius sizes depending on the overall size of crane body 102.

[0049] The first angled surface 103 and a portion of the opposing surface 106 project facially outward from the occlusal surface 16c and labial surface 17c of the tooth 13c. The posterior or lingual edge of the body 109 remains disposed on the occlusal surface 16c, while the anterior or labial edge 110 is generally not flush with any of the labial surfaces 17c of the tooth 13c. First and second connecting arms 120a and 120b project gingivally from a bonding region 111 of the opposing surface 106 adjacent the labial edge 110 toward the appliance 30. In other embodiments not shown, the connecting arms may project from another surface of the body generally adjacent the labial-most edge.

[0050] The geometry (i.e., size and shape) of the crane body 102 may be substantially similar for each carrier assembly 100 positioned on the mockup 10. The crane body 102 has an overall length from the trailing edge 109 to the leading edge 110 sufficient to position the bonding region 111 away from the tooth surface. The use of a standard crane body 102 geometry can improve both the design and manufacturability of the carrier assembly in certain circumstances, according to techniques discussed in more detail below. In alternative embodiments, the geometry of the crane body 102 may vary based on the intended bonding surface. For example, a crane body having a wider mesial-distal dimension may indicate the bonding location of an appliance on a posterior tooth, or the positioning of multiple appliances on one or more surfaces.

[0051] The sides 107, 108 include retention openings 118 extending therebetween. The retention openings 118 aid in retention of the carrier assembly 100 within a transfer apparatus and can improve the manufacturability of the assembly 100, particularly with respect to exemplary additive manufacturing techniques discussed below. As an alternative to, or in addition to, the retention openings 118, any of the surfaces of the body 102 may include protruding retention features (such as pins) or roughened surfaces. The surface roughness may be created directly during the design of the crane body 102 or may be added in a post-processing step. Any surface of the crane body 102 may include indicia identifying the associated tooth or treatment stage associated with the appliance 30. The indicia may include letters, symbols, colors, etc.

[0052] The gripping element 150 extends upward from the apex 105. The gripping element 150 includes a body 151 having a generally triangular cross-sectional shape and a weakened portion 152 including a generally rectangular sprue 153 proximate the apex 105. The shape of the gripping element body 151 and the weakened sprue 153 is not critical. The gripping element 150 may be useful for positioning carrier assemblies on the mockup 10 via manual tools, a robot, or any other feasible technique. The gripping elements 150 allow for individual placement of carrier assemblies, but can be joined together to simultaneously place two or more carrier assemblies on portions of the bow 12. The weakened portion 152 allows for separation of the gripping element 150 from the crane body 102 prior to fabrication of the transfer apparatus, as described further below.

[0053] While shown generally aligned with the crane body 102 with the weakened portion 152 parallel to the longitudinal axis 40 and front face 110 of the attachment 30, the position and / or orientation of the gripping elements 150 may be adjusted to aid in their eventual removal. For example, a group of gripping elements 150 may be rotated such that, when all are received on the mockup 10, the weakened portion 152 of each carrier assembly 100 is positioned substantially parallel to the weakened portion(s) 152 of one or more adjacent carrier assemblies 100. In other embodiments, a group of gripping elements 150 may be rotated such that, when all are received on the mockup 10, the weakened portion 152 of each carrier assembly 100 is positioned substantially collinear with the weakened portion 152 of one or more adjacent carrier assemblies 100. By positioning the gripping elements 150 in this manner, the portions of the carrier assembly 100 that engage against the apex 105 may be easier to remove en masse prior to creation of a transfer apparatus, as described in further detail below.

[0054] The body 102 further includes a recess 130 (see FIG. 8 ) having an opening 132 in the opposing surface 106 for receiving the alignment pin 200. The recess 130 is located near the rear / lingual edge 109 of the body 102 opposite the coupling region. The recess 130 is closed at one end, as shown, and terminates at an inner surface 134 over at least a portion of the height of the crane body 102 before reaching the apex 105. In other embodiments, the crane body may feature a recess that extends the entire height of the body 102 from the opposing surface to the apex, with openings on both ends. The center of the opening 132 is located in a plane “E” that extends through the height of the crane body 102 (typically collinear with the vertical axis 201 of the alignment pin 200). The fixture 30 is positioned below the opposing surface 106 in a position where the coupling surface 38 is not coincident with or coplanar with plane E to ensure that the crane body 102 can be placed onto the pin 200 without interference from the tooth surface 13 c.

[0055] The recess 130 is dimensioned to releasably receive the alignment pin 200 and prevent rotation of the carrier assembly 100 about the pin's vertical axis 201, while assisting in aligning the appliance with the vertical axis 201 so that the appliance reaches a defined mating position. The central axis of the recess is essentially aligned with the head axis 211, resulting in a parallel relationship with the vertical axis V, as shown in FIG. 29 , or it can be tilted relative to the vertical axis V. For example, as depicted in FIGS. 4 , 28 , and 29 , the recess 130 may be characterized by a trapezoidal cross-sectional shape in a plane perpendicular to the occlusal plane. The cross-sectional shape of the recess (e.g., triangular, rectangular, oval, etc.) may be uniform along the length of the body, or in other embodiments, the shape may vary. The opening 132 may be triangular, rectangular (including square), circular, oval, or polygonal. The recess 130 may be generally conical, frustoconical, pyramidal, truncated pyramidal, or other suitable shape. In some embodiments, recess 130 includes a taper that decreases in cross-sectional dimension measured parallel to the opening as it approaches apex 105. In other embodiments, recess 130 has a substantially continuous cross-sectional dimension.

[0056] The orientation, shape, and cross-sectional dimensions of the recesses 130 may be the same for each carrier assembly 100, allowing for improved standardization of manufacturing and assembly. In other embodiments, at least one of the orientation, shape, and cross-sectional dimensions may be modified to allow for correspondence between a given carrier assembly and a particular type of mating tooth. For example, a circular shape may indicate correspondence with carrier assemblies for anterior teeth, while a rectangular shape indicates correspondence with carrier assemblies for posterior teeth.

[0057] Restraint or prohibition of rotation about the vertical axis 201 and / or head axis 211 is typically achieved when the opening of the recess 130 and the cross-sectional shape of the head 210 taken perpendicular to the vertical axis 201 and / or head axis are similar, if not substantially identical. This correspondence is not strictly necessary, as, for example, a reversible friction fit between the conical head 210 and the conical recess 130 may still adequately inhibit rotation of the carrier assembly 100. Alternatively, the recess 130 may have a conical shape that is substantially non-rotating about a rectangular or other polygonal head, each shape providing facets for inhibiting rotation. As shown, the recess 130 and head 210 each include a truncated pyramidal shape with a rectangular opening 132 in the opposing surface 106. The concave profile within recess 130 generally corresponds to the convex profile of the top of the locating pin, with the pin having a small offset (e.g., 0.05 mm) to ensure that opening 132 reaches shoulder 220.

[0058] The head portion 210 and recess 130 may further include retention features for mating with corresponding features on the carrier assembly. For example, as shown in the embodiment of FIGS. 27 and 28 , the head portion 210 may include one or more indentations 217 that penetrate the angled surface 216. The indentations 217 are dimensioned to mate with ridges 133 that protrude from the inner wall within the recess 130. As will be appreciated, the ridges may alternatively be formed on the angled surface with corresponding indentations within the recess. The addition of retention features can help securely hold the carrier assemblies on the alignment pins, particularly during assembly of multiple carrier assemblies onto a physical mockup or during handling of the physical mockup in manufacturing after the carriers have been assembled onto the mockup.

[0059] When positioned on alignment pin 200, coupling region 111 is positioned a sufficient distance from the plane tangent to the apex of tooth flank 17c so that linkage arm 120 does not contact tooth flank 17c above the profile height and moves at least partially back from crane body 102 toward tool 30 toward tooth 13c. Reducing contact between linkage arm 120 and tooth 13c tends, under certain circumstances, to (a) improve release of carrier assembly 100 from a physical mockup and (b) aid in separation of tool 30 from crane body 102 because adhesive used to bond the tool to the tooth is less likely to reach linkage arm 120. As seen most clearly in FIG. 8 , the rear surfaces of linkage arms 120a, 120b form an acute angle “F” with opposing surface 106. In some embodiments, angle F is at least about 30 degrees, at least about 35 degrees, at least about 40 degrees, or at least about 45 degrees. In the presently preferred embodiment, angle "F" is less than or equal to about 85 degrees, less than or equal to about 80 degrees, or less than or equal to about 75 degrees.

[0060] 7 and 8 as including two linkage arms 120a and 120b, in some embodiments, carrier assembly 100 may include one linkage arm or three or more linkage arms. The number of linkage arms may, in certain embodiments, be determined by at least one of: (a) the orientation of long axis 40 relative to an axis normal to ground plane B; (b) the orientation of instrument long axis 40 relative to vertical axis V; and (c) the dimensions of instrument 30. Generally, but not exclusively, instruments 30 having long axes 40 oriented parallel to vertical axis V (or an axis normal to ground plane B) within a range of 35 degrees or less may be positioned using a single linkage arm 120, and instruments 30 having long axes 40 oriented parallel to vertical axis V (or an axis normal to ground plane B) within a range of 35 degrees to 90 degrees may be positioned using two or more linkage arms 120. For example, carrier assembly 100 for upper central incisor 13a (shown in more detail in FIG. 9) features a single linkage arm for positioning appliance 30 having long axis 40 oriented substantially parallel to vertical axis V of physical mock-up 10. Appliances having a length along long axis 40 greater than about 4 mm typically include, but are not limited to, at least three linkage arms 120.

[0061] The linking arms 120 can be joined to the appliance 30 at various connection points (collectively, connections 126) on the body 31. In the presently preferred embodiment, the connections 126 are spaced from the edge of the bonding surface 38 toward the opposing surface 39 to provide sufficient clearance for the linking arms 120 from the bonding tooth surface. For carrier assemblies featuring two linking arms 120, the connection points 126 are typically located at opposite corners on the long edges 32, 33 of the body 31. For carrier assemblies featuring a single linking arm, the connection 126 is typically located at the occlusally-most point on the body 31 at one of the short edges 34, 35 (i.e., the edge closest to the opposing surface 106). For carrier assemblies including generally rectangular appliances with long edge dimensions greater than about 4 mm, a third linking arm may be connected to the center of the appliance at a third connection on the appliance body. The third connection on the body may be coincident with the central axis of the appliance or may lie in a plane parallel to the central axis of the appliance. For appliances that benefit from two or more connecting arms, the connections 126 typically include at least one connection 126 on each of the proximal and distal ends of the appliance 30 (as shown in FIG. 7).

[0062] Linking arms 120a and 120b in Figures 7 and 8 diverge along a path from opposing surface 106 to connection point 126 on instrument body 31. The angle "G" between arms 120a and 120b generally depends on the dimensions of instrument 30. In some embodiments, angle "G" is at least about 30 degrees, at least about 25 degrees, at least about 20 degrees, or at least about 15 degrees. In preferred embodiments, angle "G" is about 1 degree or less, about 12 degrees or less, about 13 degrees or less, about 14 degrees or less, or about 15 degrees or less.

[0063] In some embodiments, it may be advantageous to use more than two linking arms for larger mounting bodies and / or to increase the robustness of the article during manufacturing and handling to prevent premature failure of weak sections, and therefore, more than two connection points may be incorporated into any of the articles described above, if desired. For example, the two branched linking arms 120a and 120b in Figure 7 may instead be in the form of a single fin with multiple connection points on the body 31.

[0064] The linking arm 120 is fragile when bending, twisting, compressive, or tensile forces are applied to the linking arm 120 or the carrier assembly 100, for example, by a manipulation tool. In some embodiments, the size and / or shape of the linking arm 120 may be selected to have sufficient structural integrity to allow handling of the carrier assembly 100 while easily breaking when desired. Stresses are concentrated by the linking arm 120, which has a reduced cross-sectional area at or near the connection 126 and a sudden increase in area at the surface 39 of the body 31 at the same location. The linking arm 120 can be broken by using a tool that bends or twists one of the crane body 102 or the linking arm 120, or by using a tool that shears the linking arm 120 by pushing or pulling it. In the same or other embodiments, the linking arm 120 may include stress-concentrating features, such as perforations, notches, indentations, or other weakened areas, to aid in separation of the arm 120 from the tool 30. In the same or other embodiments, the linking arm 120 may be made from a relatively rigid material that may break at or near the connection 126 .

[0065] The cross-sectional shape of the linking arms 120 (e.g., triangular, rectangular, oval, circular, oval, etc.) may be uniform along the length of the body, or in other embodiments, the shape may vary. The connecting portion 126 may be triangular, rectangular (including square), circular, oval, or polygonal. The linking arms 120 may generally be conical, truncated conical, pyramidal, truncated pyramidal, or other suitable shape. To aid in separation, each linking arm 120 is typically spaced apart by approximately 0.05 mm.2 ~0.75mm 2 , although the size of the connection region may vary based on one or more of the instrument body and linking arm geometry.

[0066] In some embodiments, one or more of the linking arms include a taper that reduces the cross-sectional dimension as the implement 30 approaches. Force may then be applied to the linking arm 120, and the thicker portion adjacent the crane body 102 can resist potential support breakage during implement deployment. Furthermore, a tapered linking arm can eliminate the need for a cutting tool; by separating the implement 30 from the linking arm 120, the user need only apply compression or tension to the thinner support end to initiate breakage. Additionally, when the crane body 102 and the implement 30 are separated, the volume of the linking arm 120 still attached to the implement 30 can be reduced. In the presently preferred embodiment, the linking arm 120 included a square, oval, or circular cross-sectional shape with a gradually decreasing taper.

[0067] In certain presently preferred embodiments, each linking arm features multiple segments, as shown in FIGS. 28-31 . The first segment 121 extends from the connection point to the pivot point 122 at a perpendicular angle to the instrument body 31, generally with an increasing taper. The second segment 123 extends from the pivot point 122 to the coupling region 111 of the crane body 102, generally back toward the tooth surface. Multi-segment linking arms, as illustrated in FIGS. 28-31 , can aid in separating the carrier assembly from the attachment and can ensure that the linking arms 120 do not contact or interfere with the mockup tooth surface or the patient's mouth. The gap between the linking arm(s) 120 and the tooth surface can also provide space for inserting a tool to aid in separating the instrument 30 from the carrier assembly 100. The segmented linking arm(s) can further provide a more predictable and desirable separation force when breaking the attachment from the carrier assembly. Segmented linking arm(s) featuring a controlled connection that is intentionally perpendicular to the instrument body may be used with any embodiment of the present disclosure.

[0068] In some embodiments, after breaking linking arm 120, a mark or small bump may remain on or in body 31 at connection 126. In some embodiments, the mark or small bump may be removed using any of a variety of automated cutting and / or abrasive tools. In other embodiments, the mark or small bump may be removed using pressure and friction generated by the action of a manual tool (e.g., a dental probe). In still other embodiments, the mark or small bump may remain if it does not interfere with instrument engagement or patient comfort. When using the segmented linking arms described above, the size of the mark or small bump may be reduced compared to other linking arms of the present disclosure.

[0069] The mating relationship between the carrier assembly and the head of the alignment pin has been illustrated above in terms of the alignment pin being received within the carrier assembly. In FIGS. 30-31 , an alternative relationship is illustrated in which the carrier assembly 1300 features a protrusion 1310 on the opposing surface 1306, and the alignment pin 1400 includes a recess 1430 formed adjacent to and below the shoulder 1404 for receiving the protrusion 1310. The protrusion 1310, as in the case of the head 210, may be conical, frustoconical, pyramidal, truncated pyramidal, or any other suitable shape. The recess 1430 is dimensioned to releasably receive the protrusion 1310 and prevent rotation of the carrier assembly 1300 about the vertical axis 1320 of the protrusion 1310 while assisting in aligning the instrument 30 so that it reaches a predetermined mating position. Other structural considerations of the carrier assembly 1300 not mentioned are the same as the corresponding features of the carrier assembly 100 and need not be repeated here. The mating relationship between the alignment pin 1400 and the carrier assembly 1300 of Figures 30 and 31 may be used with any of the other embodiments of the present disclosure.

[0070] Another embodiment of a carrier assembly 300 useful for making the transfer apparatus of the present disclosure is shown in Figures 10 and 11. Similar to assembly 100, carrier assembly 300 includes a crane body 302 having linkage arms 312, 314 projecting from a connection region 311 toward tool 30. Crane body 302 includes a substantially L-shaped cross-section, with connection region 311 providing the base of the L adjacent to front edge 310 of body 302 in the form of a third linkage arm 315. A recess 320 for receiving a registration pin is located adjacent rear edge 309 of body 302. Sides 307, 308 feature opposing openings of retention apertures 318. Considerations regarding tool 30, linkage arms 312, 314, recess 330, opening 332, and retention aperture 318 are the same as the corresponding features in carrier assembly 100 and need not be repeated here.

[0071] The third connecting arm 315 is a composite structure including a surface 316 extending in an occlusal-gingival direction and a central sprue 317 disposed substantially perpendicular to the surface 316. The central sprue 317 has a frusto-conical shape with a tapering that decreases as it approaches the appliance 30. In other embodiments, the central sprue 317 may have other shapes and dimensions similar to the connecting arms 312, 314. The central sprue 317 is disposed along the central axis 42 of the appliance 30 and is designed to be separated from or proximate to a central connection point 319 on the facial side surface 39. To aid in separation, the connection point 319 is typically spaced apart by about 0.05 mm. 2 ~0.075mm 2 , although the size of the connection area may vary based on one or more of the geometry of the implement body and the linkage arm. In an alternative embodiment, only the third linkage arm 315 is primarily used to connect the implement to the crane body without the need for one or both of linkage arms 312, 314.

[0072] The crane body 302 includes a substantially flat opposing surface 306 and a top surface 305, each of which extends in a plane substantially parallel to the opposing surface. The side surfaces 307, 308 may likewise be substantially planar. One or both side surfaces 307, 308 may be inclined relative to a plane tangent to the edge of the opposing surface at an acute draft angle. In this preferred situation, the angle is from about 3 to about 10 degrees. The draft angle may be the same or different for each side surface 307, 308. Thus, the illustrated configuration of the crane body 302 may enable the top surface 305 to be positioned in a plane parallel to the build platform of an additive manufacturing machine.

[0073] 12 is similar in almost all respects to the assembly 300 shown in Figures 10 and 11, except that when the assembly 300 is seated on the physical mock-up 10, the appliance 30 is oriented so that the long axis 40 is substantially parallel to the occlusal-gingival extending plane 316 and the vertical axis V. Accordingly, the carrier assembly 300 of Figure 12 features a single connecting arm 320 extending from the opposing surface 306 that connects to the short edge 34 of the body 31.

[0074] The above depiction and discussion has primarily focused on the coupling of a single appliance to a single tooth surface. It is contemplated that two or more appliances may be coupled to a tooth surface in accordance with the concepts of the present disclosure. FIGS. 26A-26C illustrate various alternatives for coupling multiple appliances 30a, 30b to a tooth surface 17. For example, as shown in FIG. 26A, each of these appliances 30a, 30b may be coupled to a separate carrier assembly 100a, 100b. Alternatively, as depicted in FIG. 26B, each appliance 30a, 30b may be positioned relative to a single carrier assembly 100 and attached to a single associated linkage arm 120a, 120b. As yet another alternative, the appliance 30b located gingivally relative to the more occlusal appliance 30a may be coupled to the body 31a via additional frangible linkage arms 124a, 124b. The appliance 30a remains directly connected to the crane body 102 of the carrier assembly 100 via the linkage arms 120a, 120b. Other combinations and modifications are possible and within the scope of this disclosure.

[0075] The physical mockup 10 may be manufactured as separate, integrally formed component parts. The two separate components are typically a) the bow 12, including the mold body 15 and alignment pins 200 (collectively the fixture model), and b) the carrier assembly (100, 300). In other embodiments, for example, the bow may be configured with pre-formed apertures for receiving the alignment pins. As another alternative, the bow 12, mold body 15, alignment pins 200, crane body (102, 302), and linkage arms (120, 320) may be integrally formed as a single piece, with the fixture then secured to the linkage arms and fixture mating surfaces.

[0076] Any component of the physical mock-up 10 may be manufactured by additive manufacturing. Thus, the position of the carrier assembly and alignment pins relative to the dental arch 12 may be determined computer-aided, avoiding manual assembly tolerances. Examples of suitable additive manufacturing processes include solid freeform fabrication, such as 3D printing processes, stereolithography, fused deposition modeling, thin film additive manufacturing, laser machined net forming, selective laser sintering, shape deposition manufacturing, selective laser melting, and solid grind hardening.

[0077] The physical mockup 10, and any or all of its components, can be made from a full range of 3D printing, molded, or CAD / CAM-shaped polymeric materials with specific desired strength, flexibility, translucency, or color. For example, the material can be a polymeric material that can be transparent, semi-transparent, or opaque. In some embodiments, the transparent or substantially transparent polymeric material may include, for example, one or more of an amorphous thermoplastic polymer, a semi-crystalline thermoplastic polymer, a transparent thermoplastic polymer, and a thermosetting polymer. The thermoplastic material can be selected from polycarbonate, thermoplastic polyurethane, acrylic, polysulfone, polypropylene, polypropylene / ethylene copolymer, cyclic olefin polymer / copolymer, poly-4-methyl-1 pentene or polyester / polycarbonate copolymer, styrene polymeric material, polyamide, polymethylpentene, polyetheretherketone, and combinations thereof. In another embodiment, the body material may be selected from transparent or substantially transparent semi-crystalline thermoplastics, crystalline thermoplastics, and composite materials such as polyamides, polyethylene terephthalate, polybutylene terephthalate, polyester / polycarbonate copolymers, polyolefins, cyclic olefin polymers, styrene copolymers, polyetherimides, polyetheretherketones, polyethersulfones, polytrimethylene terephthalate, and mixtures and combinations thereof. In some embodiments, the body material is a polymeric material selected from polyethylene terephthalate, polyethylene terephthalate glycol, polycyclohexylene dimethylene terephthalate glycol, and mixtures and combinations thereof. In additional embodiments, thermoset polymers include acrylics, urethanes, esters, silicones, thiolenes, epoxies, olefin metathesis, and combinations thereof.

[0078] In certain preferred circumstances, the carrier assembly is integrally formed as a single component as part of an additive manufacturing or injection molding process. The carrier assembly of the present disclosure may be made from metals (such as stainless steel alloys or other metallic materials), ceramic materials (including single-crystal and polycrystalline optically transmissive ceramics), and polymeric materials (such as fiber-reinforced polycarbonate). Suitable ceramic materials are described, for example, in U.S. Patent No. 6,648,638 (Castro et al.). Suitable materials for use in additive manufacturing include, but are not limited to, those described in WO 2020 / 104873 (Chakraborty et al.), WO 2019 / 048963 (Parkar et al.), WO 2018 / 231583 (Herrmann et al.), WO 2016 / 191534 (Mayr et al.), WO 2016 / 191162 (Mayr et al.), and WO 2014 / 078537 (Sun et al.). Other material iterations and combinations are also possible.

[0079] Under this advantageous situation, the carrier assembly containing the appliance can be formed from a hardenable composition characterized primarily for making a specific dental crown. The hardenable composition includes a resin matrix containing polymerizable (meth)acrylate(s) without urethane moieties, polymerizable urethane (meth)acrylate(s), a filler containing nanocluster(s), and an initiator system. Such compositions have a viscosity of less than 150 Pa*s at 23°C and a 1 s -1 and does not contain a softener in an amount greater than 5 wt %. More specifically, the composition may contain a polymerizable (meth)acrylate not containing a urethane moiety in an amount of 40 to 85 wt %, a polymerizable urethane (meth)acrylate in an amount of 1 to 35 wt %, nanoclusters in an amount of 5 to 40 wt %, fumed silica in an amount of 0.5 to 5 wt %, a photoinitiator in an amount of 0.01 to 3 wt %, and an organic dye in an amount of 0.001 to 0.5 wt %.

[0080] Such curable compositions can be characterized by a combination of specific properties, such as high mechanical strength, high fracture resistance, and high aesthetics, including stain resistance. The cured articles typically have the following properties, alone or in combination: 1) flexural strength of 50-200 MPa or 80-150 MPa, determined according to ISO 4049:2009 using test bars with dimensions of 6 x 4 x 25 mm (6 mm is the width of the test bar); 2) elastic modulus of 1,000-4,000 MPa, determined according to DIN EN 843-2:2007 using the flexural strength method (the elastic modulus calculation is performed within 20%-50% of the maximum force of the sample); and 3) impact strength of 5-15 kJ / m2, determined according to DIN 53453:175-05. Further details regarding these compositions can be found in EP 3638189 (Herrmann et al.). Other suitable compositions for additive manufacturing include, for example, a composition comprising a (meth)acrylate that does not contain urethane moieties, a urethane (meth)acrylate, a photoinitiator, an additive, and discrete filler particles, the discrete filler particles having an average particle size in the range of 10-40 nm and surface treated with a silane surface treatment selected from a silane surface treatment that contains (meth)acrylate moieties, a silane surface treatment that does not contain (meth)acrylate moieties, and a mixture of both, wherein the discrete filler particles are present in an amount of 20 wt% or greater, and the curable composition does not contain the following components: nano-sized particle aggregates, nano-sized particle agglomerates, fumed silica, each in an amount of 2 wt% or greater, alone or in combination, wherein the wt% are based on the total composition. The cured article typically has the following properties, alone or in combination: 1) flexural strength: 50 to 200 MPa as measured according to ISO 4049 (2019); 2) modulus of elasticity: 1 to 4 GPa as measured according to DIN EN 843-2:2007. Further details regarding such compositions can be found, for example, in commonly owned attorney docket number 84557EP002, filed July 21, 2022, entitled "Curable Composition for Producing Orthodontic Attachments."

[0081] Commercially available resins suitable for the device also include those listed in Table 1 below.

[0082] [Table 1]

[0083] The fixture, crane body, and linking arm can be formed of the same material or can be formed of different materials through one or more manufacturing processes. For example, the photopolymerizable material used to form the carrier assembly optionally includes a first composition and a second composition, such that creating the carrier assembly includes selectively curing the first composition to form the fixture 30 and selectively curing the second composition to form the linking arm and / or the crane body. In some examples, the fixture may be formed from a material having a higher ultimate strength than the material from which the linking arm is formed.

[0084] In some embodiments, the methods of the present disclosure may include a three-dimensional (3D) printing process in the fabrication of the model dental arch 12, the alignment pin 200, the carrier assembly (100, 300), the appliance 30, or any combination thereof. Three-dimensional printing may include forming an article from multiple layers of the photopolymerizable material described herein, for example, by selectively curing the photopolymerizable material layer by layer. In some embodiments, an additively manufactured article may include multiple materials bonded together. Layers of the photopolymerizable material may be deposited according to an image of the three-dimensional article in a computer-readable format. For example, the photopolymerizable material may be deposited according to preselected CAD parameters (e.g., a data file). In some embodiments, the photopolymerizable material is cured using actinic radiation, such as UV radiation, electron beam radiation, visible radiation, or a combination thereof.

[0085] The techniques described above can be repeated a selected number of times to provide a 3D article. For example, in some cases, the process can be repeated "n" times. Furthermore, it should be understood that one or more steps of the methods described herein, such as selectively applying energy to a layer of photopolymerizable composition, can be performed according to an image of the 3D article in a computer-readable format. Suitable printers include the VIPER from 3D Systems, the D30II or D90 available from Rapid Shape in Heimsheim, Germany, and the MOONRAY available from SprintRay in Los Angeles, California.

[0086] Other techniques for three-dimensional manufacturing may be suitably adapted to the techniques described herein. More generally, three-dimensional manufacturing techniques continue to be available and may be adapted for use with the photopolymerizable compositions described herein, provided they provide fabrication viscosities and resolutions tailored to specific article characteristics, e.g., continuous additive manufacturing, in which a build plate is moved (essentially) continuously through a vat of photopolymerizable material. In certain examples, equipment adapted for use in a continuous mode may be employed, such as that commercially available from Carbon 3D, Inc. (Redwood City, California), as described in U.S. Pat. Nos. 9,205,601 and 9,360,757 (both to DeSimone et al.). For example, in any of the methods described above, selective curing of the photopolymerizable material includes continuous photopolymerization of at least one of the first portion of the article or the second portion of the article. Further details of methods for additive manufacturing can be found in WO 2021 / 130624 (Cinader et al.), entitled "Preformed Orthodontic Attachments."

[0087] Physical mock-up and carrier assembly design The production of the physical mockup is typically based on a virtual mockup prepared in a computer system. Such a virtual mockup preferably corresponds to a mathematical representation of a three-dimensional shape that can be processed by a computer, for example, by a CAD system. Furthermore, the virtual mockup is preferably available in the form of computer data that can be used to control an additive manufacturing machine to produce the physical mockup defined by the virtual mockup. The virtual mockup can be designed or generated from superimposing or merging the patient's virtual dental arch with a set of virtual appliances, a crane body, and alignment pins, as described further below.

[0088] In one embodiment, the functions or algorithms described herein may be implemented in software. Software may consist of computer-executable instructions stored on a computer-readable medium or computer-readable storage device, such as one or more non-transitory memories or other types of hardware-based storage devices, local or networked. Furthermore, such functions correspond to modules, which may be software, hardware, firmware, or any combination thereof. Multiple functions may be performed in one or more modules as desired, and the described embodiments are merely examples. Software may be executed on a digital signal processor, an ASIC, a microprocessor, or other type of processor operating on a computer system, such as a personal computer, server, or other computer system, to transform such a computer system into a specially programmed machine. As used herein, the term “processor” may refer to any of the foregoing structures or any other structure suitable for implementing the techniques described herein. Furthermore, in some aspects, the functions described herein may be provided within dedicated software or hardware modules configured to perform the techniques of the present disclosure. Even when implemented in software, the techniques may use hardware, such as a processor for executing the software and memory for storing the software. In any such case, the computer described herein may define a particular machine capable of performing the particular functions described herein, and the techniques may be embodied entirely in one or more circuits or logic elements that may also be considered a processor.

[0089] In many cases, computer-readable media is provided as part of a computing device. A computing device may have one or more processors, volatile memory (RAM), a device for reading machine-readable media, and input / output devices such as a display, keyboard, and pointing device. Additionally, a computing device may include other software, firmware, or a combination thereof, such as an operating system and other application software. A computing device may be, for example, a workstation, laptop, tablet, smartphone, personal digital assistant (PDA), server, mainframe, or any other general-purpose or special-purpose computing device. A computing device may read executable software instructions from a computer-readable medium (such as a hard drive, CD-ROM, or computer memory) or may receive instructions from another source logically connected to the computer, such as another networked computer. Data may be communicated, for example, directly to an application on a mobile device and / or directly to a cloud platform system via a cellular connection, Wi-Fi router, or hub.

[0090] Generally, as shown in FIG. 13 , process 400 for designing a mockup begins with obtaining a virtual model of the patient's dental arch (step 410). The virtual dental arch model may be modified to create a solid virtual mold body (step 420). A treatment plan may be accessed or generated based at least in part on the virtual model of the patient's dental arch (step 430). Virtual appliances are obtained and placed on the teeth in treatment-relevant positions according to the treatment plan (step 440). Alignment pins and crane bodies are then placed on the arch for each appliance position (step 450). One or more linkage arms are then extruded between the body of the appliance and the crane body (step 460). Optionally, the extrusion may be performed with a draft angle relative to the body. The mold body and alignment pins are combined to create a virtual fixture model (step 480), and the crane body, linkage arms, and appliance are combined to form a carrier assembly (step 470). The fixture model and carrier assembly are maintained as separate objects for manufacturing (step 490). Individual aspects of the process are discussed in further detail below.

[0091] The treatment planning step 430 typically involves receiving information regarding the patient's orthodontic condition and / or the practitioner's selection for treatment, and then generating an initial treatment plan for repositioning the patient's teeth. This initial treatment plan may represent the start of orthodontic treatment or a new treatment phase to be initiated after the patient has undergone some orthodontic or dental treatment. The treatment plan typically includes one or more treatment phases, depending on the desired treatment modality. With CTA, the treatment plan includes multiple treatment phases, each corresponding to a tooth position. With traditional braces, the treatment plan may include a single phase with a single target position. The treatment plan is typically presented to the practitioner for modification and / or approval, although this is not strictly necessary. Appliances can be generated or selected based on the approved treatment plan, which is provided to the doctor and ultimately administered to the patient.

[0092] Process 400 can be used to generate mockups at any stage of treatment. In one embodiment, mockups can be generated for each stage of treatment (and associated appliance placement) at the beginning of treatment. In other embodiments, mockup creation can be staged to allow for patient-confirmed treatment progression, so that a new or updated model of the patient's dentition is obtained before work begins on a subsequent mockup. At various stages, the process for generating the initial treatment plan can include interaction with the treating practitioner responsible for the patient's treatment. The practitioner interaction can be conducted using a network platform and any connected participants.

[0093] As the first step in creating a virtual model of a patient's dental arch, impressions or scans of the patient's teeth (and potentially mouth tissues) are obtained (step 410). This generally involves creating a representation of the patient's teeth and gums and may involve taking wax bites, using impression materials, casting, direct contact scanning, x-ray imaging, tomographic imaging, ultrasound imaging, and other techniques to obtain information about the position and structure of the teeth, jaws, gums, and other orthodontic-related tissues. A digital data set can be derived from this data representing the current arrangement of the patient's teeth and other tissues. A virtual model of the dentition may then be reconstructed based on the digital data.

[0094] One technique that is becoming increasingly common for obtaining at least a portion of the initial placement (or any subsequent placement) is digital scanning. A virtual dental model representing the patient's tooth structure can be captured using digital intraoral scanning or by digitally scanning an impression or other physical dental model. Scanning devices that allow for providing a virtual dental arch in digital data form are intraoral scanners or intraoral contact probes, such as the True Definition™ scanner available from Midmark or the TRIOS scanner available from 3Shape A / S. Alternatively, the digital data file may be obtained by scanning an impression of the patient's teeth. Alternatively, the digital data may be obtained by scanning a physical model of the patient's teeth. The model used for scanning may be created by injecting a casting material (such as plaster of Paris or epoxy resin) into the impression of the patient's teeth and allowing the casting material to harden. To scan the model, a suitable scanning technique, such as X-ray, laser, computed tomography (CT), or magnetic resonance imaging, may be used to scan the model.

[0095] Digital data can be "cleansed" by removing any data points that represent clear errors. For example, an STL-formatted file representing a tooth surface containing data points that significantly deviate from the normal expected geometric relationship of adjacent data points can be repaired using STL processing software to remove the erroneous data points. Furthermore, missing tooth data points can be added using STL processing software to create a realistic, smoothly curved tooth shape. Alternatively or additionally, data cleansing can be performed on the data file before converting the data into an STL file. As an additional option, data of the patient's hidden features, such as the patient's tooth roots, interproximal areas, and jaw structure, can be acquired. For example, a CT scanning technique can be used to acquire data representing the patient's entire tooth structure, including the roots. The data acquired by the CT scan can then be "stitched" together with other data acquired by scanning the crowns of the patient's teeth using another scanning technique to provide a more comprehensive virtual representation.

[0096] The dental surfaces may be segmented to generate one or more separate, movable 3D tooth object models representing individual teeth. The tooth models may also be separated from the gums into separate objects. Segmentation allows a user to characterize and manipulate the tooth arrangement as a set of individual objects. Advantageously, a computer may derive diagnostic information from these models, such as arch length, occlusion setting, gap spacing between adjacent teeth, and American Board of Orthodontist (ABO) objective grading.

[0097] A tooth coordinate system defined by coordinate axes can be defined for each individual tooth surface in the virtual dental arch. The coordinate system includes a mesial-distal axis, a buccal-labial-lingual axis, and an occlusal-gingival axis for each tooth, where each axis can be calculated as being perpendicular to the other two axes. The coordinate system can be defined using calculated or selected landmarks. Alternatively, the coordinate system can be created by defining a point on a virtual tooth, receiving axis input data defining first and second axes associated with the virtual tooth, calculating a substantial normal vector for a portion of the tooth surface surrounding the point, and calculating the tooth coordinate system based on the axis input and the calculated vector. Such a method, as well as other exemplary methods for creating a tooth coordinate system, is illustrated in U.S. Pat. No. 9,622,835 (Raby et al.). The tooth coordinate system allows for various modifications to one or more virtual teeth relative to the coordinate system. Aspects that can be adjusted or modified for each tooth include torque, tip, primary rotation, mesial-distal movement (with or without interproximal reduction (IPR)), occlusal-gingival translation, and buccolabial-lingual translation. Each of these aspects involves movement in one of six degrees of freedom defined by the coordinate axes of the respective tooth surface. Such modifications also include the positioning and / or attachment of virtual analogs to the teeth.

[0098] One or both of the occlusal plane and the midsagittal plane of the dentition may be specified for the virtual model. The occlusal plane is an imaginary plane that passes through the occlusion of the teeth and generally approximates a plane. The midsagittal plane is an imaginary plane that passes longitudinally through the center of the dental arch and divides the dental arch into left and right halves. An initial guess for the occlusal plane may be based on the shape or coordinate system of some or all of the tooth surfaces belonging to each dental arch of the dentition. For example, the occlusal plane may be defined by identifying three points that tangentially contact a plane superimposed on the dentition. For a given dental arch, the three points generally include at least one contact point from the left molar, one contact point from the right molar, and one contact point from a central or lateral tooth. In another embodiment, the occlusal plane is defined as the best-fit plane relative to a point representing the origin of the dental coordinate system, as defined above. In practice, this plane represents the average of these origins, which are generally located on the incisal edges, single cusp tips, or buccal cusp tips of the teeth. The occlusal plane may also be used to calculate and define the vertical axis of the model. The vertical axis lies in a plane perpendicular to the occlusal plane and can be used to measure the orientation of the appliance on the teeth and to control the orientation of the crane body and alignment pins.

[0099] Similarly, the midsagittal plane may be derived based on the shape of the arch in the coordinate system of the tooth surfaces of the dentition. Manual adjustment of the occlusal and midsagittal planes to their position and / or orientation relative to the dentition plane can be performed as needed. The teeth and / or subgingival areas may be extruded into a plane to create a virtual support (step 420). Typically, the extrusion occurs along a path generally perpendicular to the occlusal plane to a common plane spaced about 2 to about 30 mm from either the occlusal plane or the most gingival point on the model, as desired, prior to support creation. Support creation may be accomplished before or after the virtual appliance is placed on the arch, but is preferably accomplished prior to the addition of alignment pins or crane bodies.

[0100] The method then proceeds to establish a treatment plan for modifying the dental arch (step 430). The treatment plan is used to specify the size, shape, identity, and position of appliances. The steps of the process for generating a treatment plan can be implemented as computer program modules for execution on one or more computer systems. The modeling software can provide a user interface that allows for manipulation of the digital representation of the teeth in 3D space relative to the digital representation of the patient's dental arch. The treating professional generates the treatment information, such as by selecting instructions such as the final positions of the patient's individual teeth, the duration of each phase of treatment, or the number of treatment phases, and the direction or magnitude of forces on the patient's teeth during the treatment phases. Systems and methods for generating orthodontic treatment plans can be found, for example, in U.S. Pat. No. 7,435,083 (Chisti et al.), U.S. Pat. No. 7,134,874 (Chisti et al.), U.S. Patent Application Publication No. 2009 / 0286196 (Wen et al.), U.S. Patent Application Publication No. 2010 / 0260405 (Cinader), U.S. Pat. No. 9,259,295 (Christoff et al.), and WO 2021 / 245480 and WO 2021 / 245484 (Cunliffe et al.). Further details regarding software and processes that may be used to derive the target dentition are disclosed, for example, in U.S. Pat. No. 6,739,870 (Lai et al.), U.S. Pat. Nos. 8,194,067, 7,291,011, 7,354,268, 7,869,983, and 7,726,968 (Raby et al.).

[0101] The treatment plan may be stored in a patient dental health record (DHR) along with other patient information. The DHR may be populated via information from the patient and / or treating professionals involved in the patient's care. For example, the DHR may include, but is not limited to, patient medical information items including x-rays, a 3D model of the dental patient's dentition, and / or photographs of the patient's smile. The DHR may also include other medical information, including current and past medication prescriptions, health history, genomic information, etc. For patient identification information, the DHR may include, among other things, the patient's name, address, contact information (e.g., phone number, fax number, email address), date of birth, gender, and / or dental insurance. The DHR may also include the patient's personal treatment goals (e.g., gap closure, restoration, whitening). At each treatment stage, the DHR may be updated to reflect the treatment progress and may include a new 3D model of the patient's current dentition to assist in diagnosis and further treatment planning.

[0102] The desired final positions of the teeth, or tooth positions that are the desired and / or intended end result of orthodontic treatment, can be received from a treating professional, for example, in the form of a descriptive prescription, can be calculated using a basic orthodontic prescription, or can be computationally extrapolated from a clinical prescription. Using the specification of the desired final positions of the teeth and digital representations of the teeth themselves, the final position and surface shape of each tooth can be specified to form a complete model of the teeth at the end of the desired treatment or treatment phase. The result of this process is a set of digital data structures representing the desired and / or orthodontically correct repositioning of the modeled teeth relative to the estimated stable tissues. Both the teeth and surrounding tissues can be represented as digital data.

[0103] Having both the starting position and the final target position for each tooth, the process can then define a treatment path, or tooth path, for each tooth's movement. This can include defining multiple planned sequential tooth configurations for moving the teeth along the treatment path from their initial configuration to a selected final configuration. In one embodiment, the tooth paths are optimized in a set to move the teeth from their initial positions to the desired final positions so that the teeth are moved in the most efficient and clinically acceptable manner. The path of movement for each tooth between the starting position and the desired final position may be calculated based on several parameters, including the total distance of tooth movement, the difficulty in moving the tooth (e.g., based on surrounding anatomy, the type and location of the tooth being moved, etc.), and other patient- or practitioner-specific data that may be provided. Based on this type of information, the user or the computer program may generate an appropriate number of intermediate steps (corresponding to the number of treatment steps). In some variations, the user may specify the number of steps, and the software can map different appliance configurations accordingly.

[0104] If a movement path requires a tooth to move more than a predetermined amount (e.g., 0.3 mm or less in X or Y translation), the movement path may be divided into multiple steps, with each step corresponding to a distinct target position. The predetermined amount is generally the amount an appliance or appliance configuration can move a tooth in a particular direction within the time required for each treatment step. Each appliance configuration corresponds to a planned sequential position of the teeth and represents a step along the patient's treatment path. For example, steps can be defined and calculated so that each discrete position can be followed by a linear tooth movement or simple rotation from the tooth position achieved by the preceding discrete step, and the amount of repositioning required at each step involves an orthodontically optimal amount of force on the patient's dentition. The treatment plan can include multiple stages (1-n), with the initial treatment plan beginning at time = 0.

[0105] The user / treatment professional may be provided with several candidate treatment plans to select as an initial treatment plan. The candidate treatment plans may include simulations of treatment using only photographs provided by the patient or based on more comprehensive dental imaging (e.g., x-rays, digital scans, etc.). The candidate treatment plans may be generated using a rules-based approach, an optimization-based approach, a machine learning-based approach, or specific preferences (either patient or practitioner), as outlined in WO 2021 / 245484 (Cunliffe et al.).

[0106] If the user or other professional is not entirely satisfied with the final predicted positions of the teeth, new final positions of the virtual teeth may be calculated and displayed based on the revised positions of either the virtual appliances or the virtual teeth. These steps can be repeated as many times as desired until all parties are satisfied. Data representing the selected positions of the teeth, along with each appliance's identification data (such as appliance type and bonding position), tooth identification data (such as tooth type and intraoral position), and patient data (such as name and date of birth or patient identification number), can be recorded in the DHR for further processing.

[0107] The mockup creation method then proceeds with obtaining and positioning virtual appliances relative to the virtual dental arch according to the desired treatment plan(s). While the description proceeds based on virtual appliances being virtual attachments or virtual brackets, those skilled in the art will appreciate that other virtual appliances suitable for bonding to tooth surfaces (e.g., molar tubes, buttons, cleats, sheaths, bite ramps, bite blocks, etc.) may also be accessed and coupled to the virtual dental arch. In an exemplary embodiment, the virtual appliances are obtained based on prescription-standardized, available, "off-the-shelf" physical appliances. However, those skilled in the art will recognize that the method and system may similarly be used in conjunction with appliances that may be customized for each tooth of each patient, or a combination of custom and standard appliances. In one embodiment, the virtual appliances may be selected from a library of existing appliance configurations. Such fully constructed appliances may be stored and accessible, for example, as CAD or STL (Standard Tessellation Language) files. The appliances may be stored as rendered in an accessible library, or may be generated after retrieval based on the appliance's intended location on the dental arch. The virtual instruments may be placed on the virtual arch unmodified (i.e., not subjected to any other shape adjustments) or may be modified after such placement.

[0108] The desired size, shape, and location of the appliances on the model can be determined in any of a number of ways. Different considerations may influence the size, shape, and location of orthodontic attachments compared to orthodontic brackets. For example, the final positions of the patient's individual teeth, the duration of each treatment phase, or the number of treatment phases may affect the direction or magnitude of forces on the patient's teeth during each treatment phase. In some embodiments, orthodontic attachments are used at least once but not during all treatment phases. In some embodiments, the movements achieved, the forces applied, and the engagement of each tooth with each CTA may be determined by selecting the size, shape, and location of the orthodontic attachments based on the treatment plan. Such analysis can be accomplished more than once for the treatment plan. For example, it is possible to have different attachments for each phase, or even more attachments as needed. However, in many cases, the type, location, and / or orientation of the attachments may be changed several times during the treatment plan.

[0109] As another example, the attachment may be shaped and positioned to reduce tongue and / or cheek intrusion, particularly when the CTA is not in the mouth covering the attachment. The attachment may also be shaped and positioned to facilitate removal of the CTA from the tooth by allowing specific directional disengagement of the CTA from the attachment, for example, without compromising the effectiveness of the treatment or retention of the CTA on the tooth. The attachment may also be shaped and positioned, along with a corresponding shell or opening in the CTA, to reduce the visibility of the attachment when the CTA is worn by the patient. Through the use of virtual modeling, attachments can be virtually tested, and the best attachment type, shape, position, and / or orientation can be selected. From such analysis, various physical dental attachment placement devices can be created from the virtual dental attachment placement device data utilized to create the attachments required for the various stages.

[0110] In embodiments where the appliances are orthodontic brackets, the virtual brackets can be connected to a virtual archwire, and the final positions of the teeth may be calculated based on the positions of the brackets and the selected archwire. Assuming the final positions are approved, the virtual appliances may be placed in locations corresponding to the virtual brackets. As an alternative to moving the appliances, the user may instead define desired positions for the teeth as described above, and the computer may include programming instructions that determine suitable locations for placing the appliances to move the teeth to their desired positions. Examples of such virtual orthodontic treatments are disclosed in issued U.S. Patent Nos. 6,739,869 (Kopelman et al.) and 7,354,268 (Raby et al.).

[0111] Alternatively, orthodontic appliances may be placed on the virtual arch model based on standards or guidelines from orthodontic treatment principles by Drs. McLaughlin, Bennett, and Trevisi, as taught, for example, in the textbook "Systemized Orthodontic Treatment Mechanics," First Edition, edited by Richard P. McLaughlin, BS, DDS, John C. Bennett, FDS, RCS, and Hugo Trevisi, DDS. These standards or guidelines for appliance placement may be specific to each tooth in the model and may call out the location of specific features (e.g., the occlusal-gingival height of the archwire slot) relative to the clinical crown of each tooth. Orthodontic appliances may also be placed according to specific instructions provided by the treating professional. Again, these proposed orthodontic appliance locations are optionally based on orthodontic treatment principles or other standards or guidelines known in the art. Examples of automatically placing virtual brackets on teeth are described in U.S. Pat. Nos. 7,210,929 (Raby et al.), 8,517,727 (Raby et al.), and 7,940,258 (Stark et al.), all of which are incorporated herein by reference.

[0112] The virtual instruments, whether created by the user or accessed from a virtual library, may be modified according to a treatment plan. In one embodiment, the modifying process includes increasing the three-dimensional volume represented by the virtual instruments by selectively modifying only portions of the instruments. For example, the modifying process may include flattening or reducing any concavities present in the instrument shape. The modifying process may further include adding at least virtual structures, such as connection points as described below, to the instrument shape. Undercuts may be minimized or eliminated. Furthermore, the modifying process may optionally include reducing the three-dimensional volume by selectively modifying other portions of the instruments. Those skilled in the art will recognize various possibilities for modifying shapes, for example, by changing existing shapes, adding or removing shapes, virtually copying, cutting, expanding, shrinking, or another suitable technique. Those skilled in the art will be able to further create a set of virtual instruments according to a treatment plan in any suitable manner.

[0113] Connection points on the body of the virtual instrument for the final linking arms may be created on the instrument before or after placement. In some embodiments, the connection points are stored with the virtual instrument in a library. In other embodiments, the connection points may be added during appliance modification or after the appliance has been positioned and oriented according to the treatment plan. FIG. 14 shows a virtual instrument 530 with connection points 526 defined along a long edge 532. The virtual instrument 530 is similar in all respects to the physical instrument 30. In this preferred embodiment, the connection points 526 are spaced from the edge of the connecting surface 538 toward the opposing surface 539 to provide sufficient clearance from the connecting tooth surface for the linking arms (not shown in FIG. 11 ). The number and location of connection points typically follow the same considerations as for the linking arms and can be dictated by at least one of: (a) the orientation of the appliance's long axis relative to an axis normal to the base plane B; (b) the orientation of the long axis relative to the vertical axis V; and (c) the dimensions of the instrument 30, all according to the treatment plan. Generally, but not exclusively, appliances 530 having a major axis 540 oriented within a range of 35 degrees or less parallel to the vertical axis V (or an axis perpendicular to the base plane B) feature a single connection point 526, while appliances 530 having a major axis 540 oriented within a range of 35 degrees to 90 degrees parallel to the vertical axis V (or an axis perpendicular to the base plane B) can include two or more connection points 526. The connection points 526 are typically located at opposite corners of one long edge 532, 533 of the body 531. For carrier assemblies featuring a single connecting arm, the connection point is typically located on one of the short edges 534, 535 at the occlusally-most point on the body 531 when placed on the teeth according to the treatment plan. The connection point 526 has a cross-sectional shape (here, rectangular) that generally matches the preferred cross-sectional shape of the final connecting arm. This allows the connecting arm to be extruded directly from the body 531, as discussed further below.

[0114] Referring to FIG. 15 , the virtual mold body 500 is shown with virtual appliances 530 (now bearing all the features of attachments 30) sized, shaped, and positioned on the labial surfaces 517 of the associated teeth 513 in accordance with the treatment plan. The central axis 542 of each appliance 530 is generally parallel to the base plane B. The vertical plane P of each appliance 530 may be defined by the central axis 542, the base plane B, and the occlusal surface of the associated tooth 513 that is directly occlusal to the central axis. As noted above, the base plane B may be parallel to the occlusal plane, but this is not required. The vertical plane P of each appliance may be used to position the remaining elements of the carrier assembly.

[0115] At any point in the process after the appliance location has been fully confirmed, the shape of the appliance's periphery may be used to create a recess in the bonding surface 517. For example, a virtual attachment model can be modified according to the techniques described above to have a uniform cross-sectional shape that matches the periphery of the bonding surface (e.g., the appliance base). This virtual appliance analog may be extruded in a dimension parallel to the central axis with an additional offset height (e.g., 100 microns) equal to the desired depth of the recess. The analog may then be merged with the arch model. The virtual analog can then be Boolean subtracted from the virtual tooth surface, leaving a recess with a shape that matches the periphery shape of the appliance bonding surface and a depth that matches the selected offset height. Other methods for creating a recess with the shape of the appliance bonding surface will be apparent to those skilled in the art.

[0116] With at least one implement positioned in a planned position and orientation on the virtual bow, an alignment pin and crane body can be positioned relative to each such implement. The crane body 602 and alignment pin 670 may be arranged as a composite virtual crane assembly 600, as seen in FIG. 16. The crane body 602 and alignment pin 670 in the composite assembly 600 can include any and all of the individual features of the crane bodies 100, 300 and alignment pin 200 as described above. Such an assembly 600 can be stored and accessible, for example, as a CAD or STL file, similar to the virtual implement 530.

[0117] Composite crane assembly 600 is oriented according to a Cartesian coordinate system, with opposing surface 606 extending in the Y direction from alignment pin 670 toward leading edge 610, alignment pin 670 and gripping element 650 extending in the Z direction (parallel to alignment pin's vertical axis 671), and the width of crane body 602 along the X direction. When placed on alignment pin 670, opposing surface 606 extends from alignment pin's leading edge surface 678 a sufficient distance to allow crane body 602 to overhang implement 530 and tooth surface 517. In the exemplary embodiment, this overhang of opposing surface 606 relative to alignment pin edge 678 is approximately 1.4 mm.

[0118] The composite crane assembly 600 may be accessed from a virtual library or created by adding separate virtual crane body objects to associated virtual registration pin objects. Composite crane assemblies may be categorized in the virtual library by, for example, appliance type, appliance shape, intended bonding surface, and / or corresponding bonding location on the dental arch (e.g., posterior vs. anterior). Storing composite crane assemblies in the virtual library allows, under certain circumstances, standardized crane assemblies having substantially similar geometries to be used for each tooth receiving an appliance. Standardized crane assemblies can enable more repeatable and reliable manufacturing (e.g., 3D printing) of carrier assemblies, along with more repeatable placement of attachments using a transfer device as embodied herein.

[0119] Either or both of the crane body and registration pins may be modified relative to the geometry of the components accessed from the virtual library. For example, any aspect of the composite assembly may be scaled up to account for larger appliances, larger teeth in the patient's dental arch, or particularly tilted bonding teeth. In another example, any aspect of the virtual assembly may be scaled down to accommodate a younger patient and / or smaller teeth. In other embodiments contemplated by the inventors, the selected crane body may be positioned on the dental arch independently of the registration pins, or vice versa. The remaining description will assume that the composite crane assembly 600 is used to initially position both components.

[0120] For each tooth including an appliance 530, a crane assembly 600 can be positioned near the occlusal surface 516 of the tooth. A virtual arch including the crane assembly 600 and appliance 530 positioned for each bond tooth is shown in FIG. 17. Each crane assembly is preferably positioned according to one or more standard positioning assumptions. Such assumptions may include, but are not limited to: 1) the Y axis of the composite crane assembly is aligned substantially parallel to the central axis 542 of the appliance; 2) the midpoint of the crane body 602 along the X axis is aligned with the vertical appliance plane P; 3) the opposing surface 606 is spaced from the occlusal surface 516 a sufficient distance (e.g., 0.2 mm) so that the head and shoulder of the alignment pin 670 fully protrude from the occlusal surface; and 4) the Z axis (including the vertical axis 671 of the alignment pin) is positioned perpendicular to at least one of the base surface B of the mold body 500 or the occlusal plane of the dental arch 512. 6) the leading edge 678 of the alignment pin 671 is set back from the apex of the binding flank 517, and 7) the leading edge 678 is positioned substantially parallel to the longitudinal axis 540 of the implement 530. Following one or more of the placement expectations for each composite crane assembly can allow for faster builds and easier user verification of correct placement.

[0121] 18-20 show the composite crane assembly 600 positioned on the occlusal surface 516 of the tooth 513 according to the above-described positioning projection. As shown in FIG. 18, the midpoint of the crane body 602 along the X-axis is centered on plane P. The opposing surface 606 and a portion of the alignment pin 670, including the head 672 and shoulder 674 (clearly shown in FIG. 20), project perpendicularly from the occlusal surface 516 so that the opposing surface 606 does not contact the tooth. The Z-axis of the assembly 600 is now substantially parallel to plane P and perpendicular to the ground plane of the mold body (not shown). The crane body 602 is positioned with its Y-axis aligned with the central axis 542 of the instrument 530, and the leading edge 678 of the alignment pin 670 is substantially parallel to the long axis 540 (see FIG. 19). The alignment of the Y-axis with the central axis 542 tends to symmetrically position the crane body 602 about the mesial-distal center of the instrument body 531.

[0122] The leading edge 678 of the alignment pin 670 is set back from the binding tooth flank 517, as shown in the cross-sectional view of FIG. 20 . The setback distance is sufficient to prevent the alignment pin 670 from intersecting the imaginary tooth flank and to position the leading edge 610 of the crane body 602 facially from the opposing surface 639 of the instrument 630. Positioning the leading edge 610 facially (or lingually, if the binding surface is lingually) relative to the opposing surface 639 allows the linking arm (not shown) to better avoid contacting the tooth flank 517. This positioning allows the path of travel of the linking arm to essentially return to the tooth flank 517. A sufficient setback distance may be, for example, at least 0.6 mm and no more than 1.0 mm.

[0123] 20 , the head 672 and shoulder 674 of the alignment pin 670 are positioned a sufficient height above the occlusal cusp 516 so that the opposing surface 606 of the carrier does not contact or interfere with the occlusal surface 516 of the tooth. The height may be determined relative to at least one of the tooth surface 516, the ground plane, and the occlusal plane. For example, the crane assembly 600 may be positioned such that the shoulder 674 is elevated at least 0.2 mm above the occlusal surface 516. Additionally or alternatively, the composite assembly 600 can be positioned such that the opposing surface 606 is elevated at least 0.2 mm above the occlusal plane.

[0124] The process for positioning the crane body and alignment pins, as a combined crane assembly 600 or otherwise, is repeated for each tooth 513 that will receive an appliance, according to the treatment plan. A composite model having the crane body 602 positioned adjacent the occlusal surface 516 of each tooth 513 that will receive an appliance 530 is shown in FIG. 17. The method of the present disclosure then proceeds to fabricate one or more linking arms that connect each appliance 530 to the crane body 602. As noted above, the number and location(s) of the one or more linking arms 620 are determined primarily by the type, size, and orientation of the associated appliance 530.

[0125] Each linking arm may extend generally in an occlusal-gingival direction between the connection point 526 and the bond region 611 (which may or may not be located on the opposing surface 606). In this preferred embodiment, the linking arm 620 extends in an occlusal-gingival direction from the connection point 526 to the bond region 611 on the opposing surface 606. The linking arms 620, when used, generally retain the cross-sectional shape of the connection point 526 and may each include a taper, as described above. Also, as described above, the linking arms 620 may be straight, arcuate along a single radius of curvature, include a compound curve, or include a combination thereof. Once each appliance 530 is attached to the associated crane body 602 via the required number of linking arms 620, the complete virtual mockup 700, including the completed carrier assembly 800, is available for further fabrication (see FIG. 21 ).

[0126] With the complete virtual mockup 700 in place, the method proceeds to create at least two separate object models that can be exported for subsequent manufacturing: a) fixture model 900 (see FIG. 22 ) with composite alignment pin 670 and mold body 510; and b) each carrier assembly 800, including grouped fixture 630, articulating arm 620, and crane body 602. These components of virtual mockup 700 are exported and manufactured separately; manufacturing the complete physical mockup 10 requires placing each carrier assembly on the fixture model.

[0127] Each of the fixture model 900 and carrier assembly 800 objects may be provided by combining virtual components, for example, by computer-assisted merging or overlaying. Each of the virtual fixture model 900 and carrier assembly 800 may be maintained in the form of a computer-processable three-dimensional data file and transmitted to a fabrication machine that produces their physical representation. Each carrier assembly 800 may be held as a separate object or may be joined at the gripping elements 650. The gripping elements 650 of all carrier assemblies on a mockup may be joined, or the carrier assemblies 800 may be joined to a single half-bow, a bow quadrant, or any other selected bow portion including two or more teeth. The joined carrier assemblies can provide a planar build plate for additive manufacturing or assist in assembling a physical mockup.

[0128] In some examples, fabricating at least one of the fixture model and the associated carrier assembly from the virtual mockup may include a 3D printing process. In a preferred embodiment, both the fixture model and the carrier assembly are fabricated by 3D printing, with the fixture model fabricated from a first material and the carrier assembly fabricated from a second material. Suitable materials for each are described above.

[0129] Three-dimensional printing may include, for example, forming a carrier assembly or fixture model from multiple layers of the photopolymerizable material described herein by selectively curing the photopolymerizable material layer by layer. In some examples, an additively manufactured article may include multiple materials bonded together. Layers of photopolymerizable material may be deposited according to an image of the three-dimensional article in a computer-readable format. For example, the photopolymerizable material may be deposited according to preselected CAD parameters (e.g., a data file). In some examples, the photopolymerizable material is cured using actinic radiation, such as UV radiation, electron beam radiation, visible radiation, or a combination thereof.

[0130] It should further be understood that the methods for producing 3D articles described herein can include stereolithography or vat polymerization. For example, the methods of the present disclosure may include holding a photopolymerizable composition described herein in a fluid state in a container and selectively applying energy to the photopolymerizable composition in the container to solidify at least a portion of the fluid layer of the photopolymerizable composition, thereby forming a hardened layer that defines a cross section of the 3D article. The methods may also include raising or lowering the hardened layer of the photopolymerizable composition to provide a new or second fluid layer of unhardened photopolymerizable composition on the surface of the fluid in the container, and subsequently selectively applying energy again to the photopolymerizable composition in the container to solidify at least a portion of the new or second fluid layer of the photopolymerizable composition to form a second solidified layer that defines a second cross section of the 3D article. Furthermore, the first and second cross sections of the 3D article can be bonded or adhered to each other in the z direction (or a build direction corresponding to the above-mentioned direction of raising or lowering) by applying energy to solidify the photopolymerizable composition. Additionally, selectively applying energy to the photopolymerizable composition in the container can include applying actinic radiation, such as UV radiation, visible light, or e-beam radiation, having sufficient energy to cure the photopolymerizable composition. The method for creating a physical mockup can also include planarizing a new layer of the provided fluid photopolymerizable composition by raising or lowering an elevator platform. Planarization can be achieved, for example, by utilizing a wiper, roller, or recoater. Planarization can correct the thickness of one or more layers before curing the material by removing excess material and flattening the dispensed material to create a uniformly smooth exposed or flat upper orientation surface on the printer's support platform.

[0131] The techniques described above can be repeated a selected number of times to provide a 3D article. For example, in some cases, the process can be repeated "n" times. Furthermore, it should be understood that one or more steps of the methods described herein, such as selectively applying energy to a layer of photopolymerizable composition, can be performed according to an image of the 3D article in a computer-readable format. Suitable printers include the Viper Pro SLA available from 3D Systems in Rock Hill, South Carolina, the Asiga PICO PLUS39 available from Asiga USA in Anaheim Hills, California, the D30 available from Rapid Shape in Heimsheim, Germany, and the Moonray available from SprintRay in Los Angeles, California.

[0132] A related technology, vat polymerization using digital light processing ("DLP"), also uses a container of curable polymer (e.g., a photopolymerizable composition). However, in DLP-based systems, a two-dimensional cross-section is projected onto the curable material to cure a desired portion of the entire plane intersecting the projected beam at once. All such curable polymer systems that can be adapted for use with the photopolymerizable compositions described herein are intended to fall within the scope of the term "vat polymerization system" as used herein.

[0133] One or both of the carrier assembly and fixture model may be fabricated on a build platform of any suitable shape, which may be more typical for a carrier assembly. For example, the build platform may include a substantially flat plate, one or more elongated runners, etc. The build platform may also include a frangible sprue that supports a mockup component fabricated on the build platform. For example, the sprue may extend from the build platform to a gripping element of the carrier assembly. In other examples, the sprue may extend from the build platform to a crane body. The sprue, similar to an articulating arm, is configured to break in response to bending, twisting, compression, or tension. The build platform may include indicia that identify the physical mockup component thereon. The indicia may include letters, symbols, colors, etc. For example, a build platform may be formed by the additive manufacturing techniques described herein to include text embossed on the surface of the build platform to indicate a patient or a treatment stage.

[0134] Other techniques for three-dimensional manufacturing, including, but not limited to, fused deposition modeling, selective laser sintering, and inkjet printing, may be suitably adapted for use with the methods described herein. More generally, three-dimensional manufacturing techniques remain available and may be adapted for use with the photopolymerizable compositions described herein, provided they provide fabrication viscosities and resolutions tailored to specific article characteristics, e.g., continuous additive manufacturing, in which a build plate is moved (essentially) continuously through a vat of photopolymerizable material. In certain examples, equipment adapted for use in a continuous mode may be employed, such as commercially available equipment from Carbon 3D, Inc. (Redwood City, California), as described in U.S. Pat. Nos. 9,205,601 and 9,360,757 (both to DeSimone et al.). For example, in any of the methods described above, selectively curing the photopolymerizable material includes continuous photopolymerization of at least one of the first portion of the article or the second portion of the article.

[0135] After the three-dimensional article is formed, it is typically removed from the additive manufacturing device. At this stage, the three-dimensional article typically has sufficient green strength to be handled in any remaining steps of the method. The article surface and the bulk article itself typically still retain uncured material, indicating the need for further curing. Removing residual uncured photopolymerizable material is particularly useful when the article is post-cured to minimize undesired curing of residual uncured material directly on the article. A "cured" article can include at least partially polymerized and / or crosslinked photopolymerizable material. For example, in some cases, an at least partially polymerized article is at least about 10% polymerized or crosslinked, or at least about 30% polymerized or crosslinked. In some cases, an at least partially polymerized article is at least about 50%, at least about 70%, at least about 80%, or at least about 90% polymerized or crosslinked, e.g., from about 10% to about 99% polymerized or crosslinked.

[0136] In some examples, the removal of excess uncured photopolymerizable composition on the additively manufactured article is at least partially achieved by washing with at least one solvent. Suitable solvents include, but are not limited to, propylene carbonate, isopropanol, methanol, di(ethylene glycol) ethyl ether, tripropylene glycol monomethyl ether, diethylene glycol monobutyl ether, a blend of dipropylene glycol monomethyl ether and [2-(2-methoxymethylethoxy)methylethoxy]propanol, and combinations thereof. In certain examples, the removal is at least partially achieved by moving the additively manufactured article, thereby generating a mass inertia force on the uncured photopolymerizable composition on the article, the mass inertia force being generated using a centrifuge, shaker, or mixer that rotates along one or more axes. Suitable methods for generating mass inertia forces are described, for example, in WO 2020 / 157598 (Chakraborty et al.), which is incorporated herein by reference in its entirety. For example, the source of mass inertia force may be generated using a centrifuge, shaker, or mixer that rotates along one or more axes. In some embodiments, the movement of the object is a rotation or spin of the object, which can generate mass inertia forces due to centrifugal forces. One suitable mixer that rotates along two or more axes is a double asymmetric centrifugal mixer, such as the DAC 400 FVZ available from Flacktek, Landrum, SC. ​​The double asymmetric centrifugal mixer provides simultaneous biaxial rotation that automatically reorients the article during rotation, which tends to draw uncured composition from concave features of the article in a short period of time (e.g., 20, 15, or 10 seconds or less). Suitable cleaning solutions are also described in WO 2018 / 222395 (Jahns et al.).

[0137] The methods of the present disclosure may also include subjecting the additively manufactured article to actinic radiation, heat, or both to photopolymerize the uncured photopolymerizable composition. Optionally, the article can then be immersed in another solvent (e.g., diethylene glycol ethyl ether or ethanol). Exposure to actinic radiation can be carried out using any convenient radiation source, generally UV radiation, visible light, and / or electron beam radiation, for a time ranging from about 10 seconds to more than 60 minutes. Heating is generally carried out in an inert atmosphere at a temperature ranging from about 35°C to about 80°C for a time ranging from about 10 minutes to more than 60 minutes. In some examples, a post-cure oven combining UV radiation and thermal energy can be used for the post-cure process. In some examples, post-cure can improve the mechanical properties and stability of the three-dimensional article compared to the same three-dimensional article that is not post-cured.

[0138] In some examples, the photopolymerizable material includes a ceramic material (e.g., ceramic particles and / or ceramic fibers), and the method further includes burning out the polymerized material and sintering the additively manufactured article to form a ceramic article.

[0139] For any of the above-described methods, the process optionally further includes polishing the additively manufactured article to make at least a portion of the surface of the additively manufactured article smoother than before polishing. Additionally, the method may further include treating the bonding surface 38 of one or more appliances 30 to improve surface roughness and mechanical retention. Such treatments may include etching, organosilane treatment, sandblasting, or any other known mechanical or chemical modification to strengthen the adhesive bond between the base 38 and the bonded tooth. In the case of sandblasting, the treatment includes blasting the bonding surface with silica-coated alumina sandblasting media. A solution of silane (e.g., silane in ethanol) is then applied to the treated surface and allowed to dry at room temperature for at least 5 minutes. In the same or other embodiments, the base may be bonded to a compressible material to aid in filling gaps between the base and tooth structure. Suitable compressible materials are described in U.S. Pat. No. 9,480,540 (Cinader).

[0140] Fabrication of a transfer device from an assembled physical mockup A method (1000) for fabricating a transfer device is outlined in FIG. 23. Once the components are fabricated and post-processed as desired, the method proceeds with joining the fixture model assembly and carrier assembly to create the physical mockup 10 (step 1010). This step may optionally include depositing a release agent on the fixture model. Suitable release agents include silicone fluid, PVA, sprays, and wax emulsions. Once the physical mockup is created, any gripping or interface elements that engage the crane body apex are detached from the carrier assembly (step 1020). With the gripping elements detached and the carrier assembly separated, a transfer device may then be formed on at least a portion of the mockup (step 1030). Once the device is formed (e.g., cured), the transfer device, along with each carrier assembly, is removed from the fixture model (step 1040). Advantageously, the removal may be performed vertically, facilitating separation of the transfer device from the fixture model.

[0141] Each carrier assembly (100, 300, 1300) is placed on the alignment pins (200, 1400) so that the receptacles (130, 330, 1430) engage the protrusions (210, 1310). The assemblies (100, 300, 1300) are pushed in the gingival direction until the opposing surfaces engage the shoulders before contacting the occlusal surfaces of the bonded teeth. The carrier assemblies may be placed one by one or joined together in one or more groups. The carrier assemblies may be placed manually by a technician, e.g., using markings on the carrier assembly and / or fixture, or according to guidelines specifying the location of a given carrier assembly based, e.g., on the geometry of the appliance or the geometry of the crane body. For example, a clinician or technician may use a tool such as tweezers, retaining ring pliers, or other suitable tool to engage the crane body and place the carrier assembly on the fixture model. As an alternative to manual placement of the carrier assembly, a computer-controlled robotic arm (e.g., a pick-and-place robot) may be used to sequentially grasp each instrument and place it on the associated tooth. For example, information regarding the placement of a complex crane assembly may be used in a set of instructions to control the movement of the robotic arm so that the carrier assembly is placed at a corresponding selected location on the fixture model.

[0142] Once any or all of the carrier assemblies are satisfactorily positioned, any elements of the carrier assemblies that engage against the apex of the crane body are removed and optionally discarded (step 1020). Elements such as gripping elements can be removed, for example, at weakened sections. Removal of these elements allows for the creation of appliances with reduced height above the tooth surface, potentially improving patient comfort and reducing the amount of material required to form the appliance. With each carrier assembly positioned on its associated alignment pin, each appliance is predictably positioned in its intended bonding location and orientation on the bonding tooth surface.

[0143] Once the physical mockup (i.e., the bonded carrier assembly and fixture model) has been satisfactorily generated, a transfer device can be fabricated over the mockup (step 1030). This may include sending instructions to a pressure-forming or thermoforming machine to pressure-form or thermoform one or more sheets of material over the physical mockup to form a negative replica or shell. The sheets may be, for example, sheets of deformable plastic (e.g., elastic thermoplastic). The sheets of material may be heated to a temperature at which the sheets become pliable. Simultaneous pressure may be applied to the sheets to form them around the mockup. When the sheets cool, they have a shape that conforms to the mockup. The internal shape of the plastic shell substantially conforms to the patient's current dental arch. Prior to forming the plastic shell, a release agent may be applied to the mockup to facilitate subsequent removal of the mold from the plastic shell. The shell may be trimmed using laser or mechanical milling techniques to remove excess or unwanted material.

[0144] One exemplary method for making a transfer device in the form of a tray involves the use of multiple sheets of material, as described in U.S. Pat. No. 10,368,961 (Paehl et al.). The method involves placing an elastic sheet over the occlusal sides of the teeth represented by a physical mock-up, and a plastic sheet is placed over the elastic sheet. The elastic and plastic sheets are deformed toward the physical mock-up. This can be accomplished by a vacuum created below the elastic and plastic sheets or pressure above the elastic and plastic sheets. At least the plastic sheet may be heated before and / or during deformation. The plastic sheet is typically solidified by cooling to provide sufficient rigidity for handling.

[0145] In other embodiments, the method can optionally include placing an elastomeric spacer over a physical mockup and thermoforming a rigid layer of transfer device (e.g., PETG, etc.) over the mockup. The spacer material can be any one of a number of materials, including dental putty, thermosetting materials, thermoplastics (including nylon), thermoplastic elastomers, and composite materials (e.g., glass-filled nylon). Further details regarding spacers can be found in U.S. Patent No. 7,762,815 (Cinader et al.).

[0146] Optionally, a transfer device may be fabricated with an occlusal stop member, as also described in U.S. Patent No. 7,762,815. The occlusal stop member typically includes a flat upper surface and a bottom surface having a shape, such as a recess, that matches the shape of the occlusal tip of the patient's dental arch. In certain embodiments, the occlusal stop member has one or more recesses corresponding to only some teeth in the dental arch, although it is also possible to construct an occlusal stop member with one or more recesses corresponding to each tooth in the dental arch. Other variations are possible. For example, the occlusal stop member may extend only along a portion of the dental arch rather than along the entire dental arch. Multiple stop members may be provided, and in some cases may be spaced apart and optionally connected to one another. The occlusal stop member may be chemically or mechanically bonded to a plastic sheet and / or a hardenable material.

[0147] It should be understood that the transfer tray may be formed solely from one or more layers of deformable plastic sheeting, without the elastic sheet or flexible positioning layer. In such an embodiment, the plastic sheet may be placed directly adjacent to the occlusal surface of the physical mock-up, without the spacing provided by the elastic sheet. Thus, upon deformation, the plastic sheet directly surrounds the teeth and carrier assembly of the physical mock-up, directly forming the receptacle used to removably hold the carrier assembly for subsequent bonding. In such streamlined transfer device embodiments, the physical mock-up may be coated with a release agent to aid in removal of the transfer tray from the mock-up. Following typical methods used to fabricate transfer devices, the resulting tray represents a negative replica of at least a portion of the physical mock-up.

[0148] Suitable materials for making thermoformed transfer devices are well known in the art, and therefore, the choice of material is not critical. In an exemplary embodiment, the transfer device is formed from COPYPLAST low-density polyethylene, available from Scheu Dental Group of Iserlohn, Germany. The use of a transparent material for the component layer can facilitate verification of proper placement of the transfer device and associated appliances on the teeth.

[0149] Alternatively, the transfer device may include a dental impression material or a bite registration material. Dental impression materials can be based on different chemistries and can crosslink by various chemical reactions (including addition-curing and condensation-curing materials). Dental impression materials can be classified according to their hardening mechanism (e.g., addition-curing or condensation-curing). Dental impression materials can also be classified according to their consistency. In addition to low-viscosity dental impression materials, there are high-viscosity so-called putty-like dental impression materials. Examples of dental impression materials include materials based on alginate(s), hydrocolloids, polysulfides, polyether technology, addition-curing silicone materials (e.g., VPS materials), and condensation-curing silicone materials. Dental impression materials are typically provided as two-component systems consisting of a base paste and a catalyst paste that are mixed before application. The mixed paste is typically applied using a syringe-type device.

[0150] Dental impression materials typically have the following characteristics: consistency (according to ISO 4823): comparable low viscosity behavior (consistency 3), medium viscosity (consistency 1 or 2), or putty-like high viscosity behavior (consistency 0); setting time: within about 15 minutes after mixing at ambient conditions (e.g., 23°C); Shore A hardness (according to ISO 4823, 24 hours): at least about 20 or at least about 40; tensile strength (according to DIN 53504): at least about 0.2 MPa or at least about 3.0 MPa; elongation at break (according to DIN 53504): at least about 30%, or at least about 150%, or at least about 200%; recovery from deformation (according to ISO 4823): at least about 90%, or at least about 95%, or at least about 98%. Suitable dental impression materials are also described in EP 2072029 (Bissinger et al.), U.S. Pat. No. 6,677,393 (Zech et al.), EP 1512724 (Zech et al.), U.S. Pat. No. 6,127,449 (Lechner et al.), U.S. Pat. No. 8,007,579 (Klettke et al.), and U.S. Pat. No. 5,569,691 (Guggenberger et al.). Suitable dental impression materials are commercially available, for example, from 3M ESPE under the IMPREGUM or IMPRINT trademarks, as well as from numerous other suppliers and trademarks.

[0151] After the transfer device has cured or otherwise solidified, the device is removed from the fixture model (step 1040). The carrier assembly is held within the device by at least intimate contact between the transfer device material and the crane body. As described above, this contact may be enhanced by retention features on the surface of the crane body. The orientation of the alignment pins on the fixture model allows the transfer device to separate substantially vertically, possibly along the vertical axis V of the fixture model. The shell may be trimmed by laser or mechanical milling techniques to remove excess or unwanted material before or after removal.

[0152] 24-25 show the completed transfer device 1100. The formed transfer device 1100 (here, a U-shaped tray) substantially matches the teeth of the physical mockup. The device includes a series of recesses with occlusal receptacles (represented by receptacles 1120) that substantially correspond to the outer surface of the crane body 1202 and channels (represented by channels 1130) that substantially correspond to the outer surfaces of the linking arms 1220 and appliances 1230 (which may reflect any of the carrier assemblies 100, 300, 1300). The occlusal receptacles and channels may be in fluid communication within the recesses, although this is not strictly required. The inner wall portions typically have contours that match the contours of the patient's individual teeth and an overall configuration that matches the orientation of each tooth relative to other teeth in the same dental arch. The inner wall portions contact the labial, occlusal, and lingual surfaces of the teeth when seated on the dental arch, although other structures may omit surfaces that do not include receptacles and / or channels 1120, 1130.

[0153] The body of the transfer device 1100 defines a plurality of shells 1150 (shells 1150). Each of the shells 1150 is configured to receive the outer surface of a respective tooth. In this manner, the transfer tray is configured to align with the patient's dentition. Each of the shells 1150 that align with the bonding teeth is configured to include a respective occlusal receptacle 1120 and channel 1130 within the shells 1150 that are collectively molded to surround at least a portion of a respective carrier assembly 1200.

[0154] The channels 1130 may have any suitable cross-sectional shape or combination of shapes (e.g., trapezoidal, dome-shaped, etc.). Each channel 1130 within a transfer device may have the same or different cross-sectional shapes. In other embodiments, a particular group of channels 1130 may include the same cross-sectional shape as each other within the group, and may have a cross-sectional shape that differs from the cross-sectional shapes of groups located in different quadrants or locations on the transfer device 1100. In a preferred present situation, the device lacks any interior surface within the channels 1130 located between one or more linkage arms 1220 and the bonding tooth surface on the associated carrier assembly 1200. This configuration may aid in the separation of the instruments 1230 from the transfer tray 1100.

[0155] The transfer device need not extend across the entire face of the linkage arm or instrument. For example, the recess may include an engagement receptacle that covers the crane body 1202 and a reduced-length channel 1130 that extends across a limited portion of the linkage arm 1220. The connection portion 1226 and instrument 1230 remain exposed. Alternatively or additionally, the recess may include only an engagement receptacle, with the linkage arm and instrument 1230 exposed. Furthermore, the engagement receptacle need not encompass or surround the entire surface of the crane body 1202. The device may include a combination of such exposed instruments, partially exposed instruments, and instruments received within a channel. Leaving the instrument 1230 at least partially exposed may, in certain embodiments, facilitate separation of the instrument 1230 from the crane body 1202 when the instrument 1230 is properly coupled to the coupling tooth.

[0156] Additionally, a transfer device may be used to bond only a single appliance to a patient's tooth. For example, a portion of the transfer device described above may be used to bond a single appliance to a single tooth at a time after other appliances have been bonded, such as when access to the tooth is first blocked by other teeth. As another example, a portion of the transfer device described above may be used to reattach one or more appliances that have inadvertently become detached from a tooth, or to bond a new appliance to a tooth to replace the original appliance.

[0157] An adhesive may be applied to the bonding surface of the appliance 1230 before it is seated on the patient's dental arch. In some embodiments, the dental adhesive used may include a light-cure adhesive, a chemical-cure adhesive, a dual-cure adhesive, 3M RELYX Ultimate Adhesive Resin Cement, SCOTCHBOND Universal Adhesive, TRANSBOND XT Primer, TRANSBOND MIP Primer, or APC FLASH-FREE adhesive (all available from 3M Company, St. Paul, Minnesota), or the like. The adhesive may be selected for compatibility with the materials used to fabricate the appliance to securely bond the attachment to the tooth. After applying the adhesive to the bonding surface, the transfer device 1100 may be positioned on the patient's tooth.

[0158] The clinician or any other treating professional may first position the transfer device 1100 on the dentition. Then, in examples where the dental adhesive includes a light-curing adhesive, the clinician may direct a selected wavelength of radiation, e.g., actinic radiation, onto one or more of the appliances 1230 to cure the light-activated resin, thereby bonding the appliances 1230 to the bonding tooth surface. In other examples, the clinician may use an activator or other means to initiate curing of the adhesive just before positioning the transfer device 1100 on the arch or while the transfer device 1100 is positioned on the arch. The teeth may optionally be etched or primed before the transfer tray is seated on the arch.

[0159] Once the adhesive has properly cured, each appliance 1230 may be separated from its associated crane body 1202, preferably near the connection point on the appliance body. The appliance is removed from the dental arch and the patient's mouth. The treating professional may then remove any unwanted vestiges of the connecting arms.

[0160] Kits and assemblies of the described appliances are also contemplated herein. One or more of the attachments described herein may be pre-coated with a suitable orthodontic adhesive and packaged in a container or series of containers, as described, for example, in U.S. Pat. Nos. 4,978,007 (Jacobs et al.), 5,015,180 (Randklev), 5,429,229 (Chester et al.), and 6,183,249 (Brennan et al.), and U.S. Patent Application Publication No. 2008 / 0286710 (Cinader et al.).

[0161] The various techniques of this disclosure may be implemented in a wide variety of computing devices, such as servers (including cloud), laptop computers, desktop computers, notebook computers, tablet computers, handheld computers, smartphones, etc. Any component, module, or unit is described to emphasize functional aspects and does not necessarily require realization by different hardware units. The techniques described herein may also be implemented in hardware, software, firmware, or any combination thereof. Any features described as modules, units, or components may be implemented together in an integrated logic device or separately as separate but interoperable logic devices. In some cases, various features may be implemented as an integrated circuit device, such as an integrated circuit chip or chipset.

[0162] When implemented in software, the technique may be realized at least in part by a non-transitory computer-readable medium comprising instructions that, when executed on a processor, perform one or more of the methods described above. The computer-readable medium may comprise a tangible computer-readable storage medium and may form part of a computer program product, which may include packaging materials. The computer-readable storage medium may include random access memory (RAM) such as synchronous dynamic random access memory (SDRAM), read-only memory (ROM), non-volatile random access memory (NVRAM), electrically erasable programmable read-only memory (EEPROM), flash memory, magnetic or optical data storage media, etc. The computer-readable storage medium may also include non-volatile storage devices such as hard disks, magnetic tapes, compact discs (CDs), digital versatile discs (DVDs), Blu-ray discs, holographic data storage media, or other non-volatile storage devices. The term "processor," as used herein, may refer to any of the foregoing structures or any other structure suitable for implementing the techniques described herein. Furthermore, in some aspects, the functionality described herein may be provided within dedicated software or hardware modules configured to execute the techniques of the present disclosure. Even when implemented in software, the techniques may use hardware, such as a processor for executing the software and memory for storing the software. In any such case, a computer as described herein may define a particular machine capable of performing the particular functions described herein. The techniques may also be implemented entirely in one or more circuits or logic elements that may also be considered a processor.

[0163] The patents, patent documents, and patent applications cited herein are incorporated by reference in their entirety as if each were individually incorporated. While specific embodiments of the present disclosure have been shown and described, it is understood that these embodiments are merely illustrative of the many possible specific configurations that can be devised in application of the principles of the present disclosure. Those skilled in the art can devise numerous and varied other configurations in accordance with these principles without departing from the spirit and scope of the present disclosure. Thus, the scope of the present disclosure should not be limited to the structures described in this application, but only by the structures described by the language of the claims and the equivalents of those structures.

Claims

1. 1. A system for indirect bonding of orthodontic appliances, comprising: a transfer body defining a shell configured to receive an outer surface of a tooth of a dental arch, the transfer body including an inner surface that substantially conforms to a contour of at least one tooth of the dental arch, the transfer body defining at least one recess within the shell; an orthodontic appliance carrier positioned against the occlusal surfaces of the teeth, a crane including a crane body having a tooth-facing surface, the facing surface configured to not contact occlusal surfaces of the teeth when the transfer body is placed on the dental arch; the orthodontic appliance including a base for bonding the appliance to the teeth and a body including a periphery; an orthodontic appliance carrier comprising one or more linkage arms configured to connect the crane body to the appliance, the linkage arms being frangible between the crane and the appliance.

2. 2. The system of claim 1, wherein the transfer body defines a plurality of shells, each shell of the plurality of shells configured to receive a respective tooth of the plurality of teeth, and the transfer body defines a respective recess in at least two respective shells.

3. The system of claim 2 , wherein each recess includes at least the crane body.

4. The system of any one of claims 1 to 3, wherein the crane body has a polygonal cross-sectional shape.

5. The system of claim 4 , wherein the crane body further includes opposing side surfaces and at least one angled surface opposing the tooth opposing surface.

6. The system of claim 5 , wherein an inner surface of the recess contacts at least the inclined surface of the crane body.

7. The system of claim 6 , wherein the inner surface of the recess contacts at least one of the inclined surface and the side surface.

8. 8. The system of claim 1, wherein the opposing surface includes a connecting region from which the connecting arm projects, the connecting region being located in a labial or lingual direction from the tooth when the transfer body is seated on the dental arch.

9. The system of claim 8 , further comprising a channel surrounding the one or more linking arms and at least a portion of the instrument.

10. 10. The system of claim 8 or 9, wherein the one or more connecting arms project from the opposing surface back toward the tooth surface when the transfer body is seated on the dental arch.

11. The system of any one of claims 1 to 10, wherein each of the one or more linking arms includes at least one stress concentration area between the opposing surface and the instrument.

12. The system of any one of claims 1 to 11, wherein the tool body includes three or more edges, and each linkage arm is connected to the body along the same edge.

13. The system of any one of claims 1 to 12, wherein the appliance body has the shape of an orthodontic attachment configured to transfer forces from clear tray aligners to the teeth.

14. The system of any one of claims 1 to 13, wherein the appliance is an orthodontic bracket.

15. The system of any one of claims 1 to 14, wherein the crane, one or more articulating arms, and implement are integrally formed by additive manufacturing.

16. The system of any one of claims 1 to 15, wherein the transfer body comprises a thermoforming material.

17. The system of any one of claims 1 to 15, wherein the transfer body comprises an impression material.

18. 18. The system of claim 1, wherein the opposing surface includes a connecting region from which the connecting arm projects, the connecting region projecting outward in a labial direction, the appliance configured to be coupled to a labial surface of the tooth.

19. 19. The system of any one of claims 1-18, wherein the opposing surface includes a connecting region from which the connecting arm projects, the connecting region projecting outward in a generally lingual direction, the appliance configured to be coupled to a lingual surface of the tooth.

20. 1. A carrier for use in bonding orthodontic appliances to a patient's teeth, comprising: a crane including a crane body having a tooth-facing surface, the facing surface configured to avoid contacting occlusal surfaces of the teeth when the crane is placed on the dental arch; the orthodontic appliance including a base for coupling the appliance to the teeth and a body including a periphery; a carrier comprising one or more linkage arms configured to connect the crane body to the implement, the linkage arms being frangible between the crane and the implement.

21. 21. The carrier of claim 20, wherein the body has the shape of an orthodontic attachment configured to transfer forces from a clear tray aligner to the teeth.

22. 21. The carrier of claim 20, wherein the orthodontic appliance is a first appliance and the carrier includes a second appliance connected to the crane via an articulating arm.

23. 22. The carrier of claim 20 or 21, wherein the facing surface includes a recess having an opening and a depth extending through a portion of the height of the crane body measured between the facing surface and the apex of the crane body.

24. 24. The carrier of claim 23, wherein the recess has a shape that includes at least one rotation-restraining surface or surface feature.

25. A carrier according to any one of claims 22 to 24, wherein the recess comprises a taper that decreases in cross-sectional dimension from the opening to the apex.

26. A carrier according to any one of claims 20 to 25, wherein each arm includes at least one stress concentration area on the opposing surface or on the device body.

27. The carrier of any one of claims 20 to 26, wherein the or said one or more linking arms comprises an oval or circular cross-sectional shape.

28. The carrier of any one of claims 20 to 27, wherein the at least one linkage arm of the one or more linkage arms includes a taper that decreases in cross-sectional dimension from the crane to the implement.

29. A carrier according to any one of claims 20 to 28, wherein each linkage arm of the one or more linkage arms projects from the opposing surface.

30. 30. The carrier of claim 29, wherein each linking arm projects along an axis oriented at an acute angle to the area of ​​the opposing surface from which the arm projects.

31. 30. The carrier of claim 28, wherein the one or more linkage arms comprise a first linkage arm and a second linkage arm, the first linkage arm diverging from the second linkage arm as the arm moves between the crane and the implement.

32. A carrier according to any one of claims 20 to 27, wherein each linkage arm moves along a curved path between the crane and the implement.

33. 33. A carrier as claimed in any one of claims 30 to 32, wherein the facing surface includes a recess having an opening and a depth extending through a portion of the height of the crane body, the facing surface including a coupling area spaced from the opening through which the linking arms project, each linking arm projecting from the coupling area in a direction back towards the trailing edge of the crane body.

34. A carrier according to any one of claims 20 to 33, wherein the crane includes sides that extend substantially perpendicular to a plane.

35. 35. The carrier of claim 34, wherein at least one side includes at least one retention feature, said retention feature including a protrusion or a recess.

36. 36. A carrier as claimed in any one of claims 20 to 35, wherein the implement body periphery includes three or more edges, each linkage arm being connected to the implement body along the same edge, the edge to which the one or more linkage arms are connected being oriented in a plane substantially parallel to the facing surface of a crane.

37. 37. The carrier of any one of claims 20 to 36, wherein the body periphery includes three or more edges, each linking arm being connected to the body along the same edge, and the edge to which the one or more linking arms are connected is oriented in a plane oriented at an oblique angle to the facing surface of the crane.

38. The carrier of any one of claims 20 to 37, wherein the crane, the connecting portion, and the tooling are integrally formed by additive manufacturing.

39. 40. The carrier of claim 38, wherein the tool comprises a first additively manufactured material and the crane and one or more articulating arms comprise a second additively manufactured material, the first material being different from the second material.

40. 40. The carrier according to any one of claims 20 to 39, wherein the carrier comprises a material having a flexural strength of 50 to 200 MPa or 80 to 150 MPa, determined according to ISO 4049:2009 using test bars with dimensions of 6x4x25 mm, where 6 mm is the width of the test bar, and a modulus of elasticity of 1,000 to 4000 MPa, determined according to DIN EN 843-2:2007 using the flexural strength method, the calculation of the modulus being made in the range of 20% to 50% of the maximum force of the sample.

41. 41. The carrier of claim 40, wherein the carrier comprises a resin cured from a polymerizable composition, the composition comprising: polymerizable (meth)acrylate(s) free of urethane moieties in an amount of 40 to 85 wt %, polymerizable urethane (meth)acrylate(s) in an amount of 1 to 35 wt %, nanoclusters in an amount of 5 to 40 wt %, fumed silica in an amount of 0.5 to 5 wt %, a photoinitiator in an amount of 0.01 to 3 wt %, and an organic dye in an amount of 0.001 to 0.5 wt %, based on the total weight of the composition.

42. 1. A physical mockup for creating a transfer device, comprising: a representation of at least a portion of a dental arch, the dental arch including a plurality of teeth, each tooth including an occlusal surface, a lingual surface, and a labial surface; A mock-up in which one or more teeth include alignment pins projecting upward from the occlusal surface.

43. 43. The mockup of claim 42, wherein the mockup includes a first alignment pin and a second alignment pin, each alignment pin including a head having a shape, the dimensions of the cross-sectional shape being substantially the same for each of the alignment pins.

44. 43. The mockup of claim 42, wherein each alignment pin includes a head having a shape, and wherein the shape or dimensions of the first alignment pin head are different from the shape or dimensions of the second alignment pin head.

45. 45. The mockup of claim 43 or 44, wherein the shape is polygonal or conical.

46. 46. ​​The mockup of claim 45, wherein the shape is a truncated cone, a pyramid, or a truncated pyramid.

47. 10. The mock-up of claims 42-26, wherein the lingual or labial surface of at least one tooth includes a recess sized to receive the base of an orthodontic appliance.

48. 48. The mockup of claim 47, wherein the recess comprises a shape complementary to the shape of the orthodontic appliance, the recess being recessed relative to the surrounding tooth surface.

49. 49. The mockup of any one of claims 42 to 48, wherein at least one alignment pin includes a shoulder adjacent the occlusal surface of the tooth, the shoulder providing a substantially planar occlusal surface at the base of the alignment pin.

50. 50. The mockup of any one of claims 42 to 49, further comprising one or more alignment features extending from the occlusal surface adjacent the base of the alignment pin.

51. and an instrument carrier on each alignment pin of the one or more alignment pins, the instrument carrier comprising: a crane including a crane body having a tooth-facing surface, the facing surface configured to not contact occlusal surfaces of the teeth when the transfer body is placed on the dental arch; the orthodontic appliance including a body including a base and a periphery for coupling the appliance to the tooth; 43. The mockup of claim 42, comprising one or more linkage arms configured to connect the crane to the implement, the linkage arms being frangible between the crane and the implement.

52. 51. The mockup of claim 50, wherein the proximal region of the carrier includes a recess configured to receive the alignment pin, the recess including a shape complementary to the alignment pin and constraining rotation of the carrier about the longitudinal axis of the pin.

53. 53. The mockup of claim 52, wherein the tooth-facing surface does not contact the occlusal surface of the tooth.

54. 1. A method for making a transfer tray for one or more orthodontic appliances, comprising: providing a physical mock-up including a representation of at least a portion of a dental arch, the dental arch including a plurality of teeth, each tooth including an occlusal surface, a lingual surface, and a labial surface, one or more teeth including alignment pins projecting upwardly from the occlusal surface; for each tooth including a registration pin, placing an appliance carrier on said registration pin, said carrier comprising: a crane including a crane body having a tooth-facing surface, the facing surface configured to not contact occlusal surfaces of the teeth when the transfer body is placed on the dental arch; the orthodontic appliance including a base for coupling the appliance to the tooth and a body including a periphery; an orthodontic appliance carrier comprising one or more connecting arms configured to connect the crane to the appliance, the connecting arms being frangible between the crane and the appliance; forming a tray over the mock-up and the carrier.

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