ORTHODONTIC ALIGNERS WITH ISOLATORY SEGMENTS - Patent application

Abstract

To provide an orthodontic aligner.SOLUTION: A method comprises forming a plastic orthodontic aligner having a plurality of cavities formed to receive at least portions of a plurality of teeth of a patient, where a first segment of the orthodontic aligner corresponds to a first subset of the plurality of cavities for moving a first subset of the plurality of teeth of the patient, and where a second segment of the orthodontic aligner corresponds to a second subset of the plurality of cavities.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] Technical Field FIELD OF THE DISCLOSURE Embodiments of the present invention relate to the field of orthodontics, and more particularly to plastic orthodontic aligners. [Background technology]

[0002] Orthodontic procedures generally involve the desired alignment and repositioning of a patient's teeth for the correction of malocclusion and / or aesthetic improvement. To achieve these goals, orthodontic appliances such as braces, retainers, plastic aligners (also called shell aligners), etc. may be applied to the patient by a dental practitioner. The appliances are configured to exert a force on one or more teeth to affect the desired tooth movement. The application of the force may be periodically adjusted by the practitioner (e.g., by changing appliances and using different types of appliances) to gradually reposition the teeth to the desired alignment. [Brief description of the drawings]

[0003] [Figure 1] FIG. 1 illustrates a segmented plastic orthodontic aligner according to one embodiment. [Diagram 2] FIG. 13 illustrates a segmented plastic orthodontic aligner according to another embodiment. [Diagram 3] FIG. 13 illustrates a segmented plastic orthodontic aligner according to another embodiment. [Figure 4] FIG. 13 illustrates a segmented plastic orthodontic aligner according to another embodiment. [Diagram 5] FIG. 13 illustrates a plastic orthodontic aligner according to another embodiment. [Figure 6] FIG. 13 illustrates a set of plastic orthodontic aligners designed to apply force to the upper back teeth without applying force to the upper front teeth, according to another embodiment. [Figure 7]FIG. 1 is a flow diagram of one embodiment for a method of orthodontic treatment using a series of aligners. [Figure 8] FIG. 13 is a flow diagram of one embodiment for a method of manufacturing a segmented aligner with connectors that isolate force transmission between the segments. [Figure 9] FIG. 13 is a flow diagram of another embodiment for a method of manufacturing a segmented aligner with connectors that isolate the force transmission between the segments. [Figure 10] 13 illustrates a flow diagram of another embodiment for a method of manufacturing a segmented aligner with connectors that isolate the force transmission between the segments. [Figure 11] 1 is a block diagram of an exemplary computing device in accordance with an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0004] The present invention is illustrated by way of example and not by way of limitation in the figures of the accompanying drawings.

[0005] In some cases, it may be preferable to isolate forces applied to different groups of teeth. Current plastic aligners may not be able to effectively isolate forces between different sets of teeth (e.g., between front and back teeth). Described herein are embodiments of orthodontic aligners that include segments joined by connectors that isolate forces between the segments (e.g., isolating the segments such that no or only minimal forces are applied between the segments), and methods of manufacturing and using such orthodontic aligners. Force transmission between the segments may be reduced compared to force transmission between different portions of a non-segmented orthodontic aligner. The segments and connectors may be individually manufactured and provided as separate elements and may be separate from a larger aligner, as described below. The orthodontic aligners described herein, as well as related systems and methods, may be employed as part of a dental treatment procedure to reposition one or more teeth, maintain the position of one or more teeth, or any suitable combination thereof. Orthodontic aligners can include multiple separate shell segments, each with a cavity shaped to receive at least a portion of a patient's teeth, joined by elastic, rigid, or semi-rigid connectors to form a single appliance shell. The geometry, configuration, and material properties of the shell segments and / or connectors can be selected to minimize or eliminate force transmission between the segments. For example, the connectors can be designed to prevent clinically significant forces from being applied to one or more teeth by segments that are not covering the teeth. A clinically significant force is a force sufficient to change the position or alignment of the teeth. This allows for separate and distinct forces to be applied to the teeth covered by each of the segments without interaction or opposing forces from the other segments. Additionally, the segmented aligners described herein can, in some cases, accommodate greater tooth movement than conventional non-segmented aligners, thus reducing the number of different aligners used to complete a course of dental treatment.In some cases, force transmission can be minimized or eliminated in some directions without affecting other directions, for example, distal or mesial forces can be minimized without reducing other forces between the segments.

[0006] In some cases, the stiffness of the separating shell segments is greater than the stiffness of the connectors. This allows an isolating force system to be created and allows treatment of one or more specific teeth without a response force on other teeth. Segmented aligners coupled with force isolating connectors can improve the treatment of certain malocclusions, where separation force treatment is performed to separate groups of teeth.

[0007] Shell segments may vary in design. In some cases, one or more separate shell segments forming the aligner may be configured to receive only a single tooth. In some embodiments, one or more separate shell segments may be configured to span or receive multiple teeth. An aligner may include segments of the same or different types with respect to the number of teeth the segments span or receive. For example, an appliance may include some separate shell segments that span or receive a single tooth and some separate shell segments that span or receive multiple teeth. Connectors with a variety of shapes, material configurations, and designs may be used. The same or different types of connectors may be used between each pair of adjacent segments.

[0008] The aligners described herein may be included in a series of aligners to provide an orthodontic system for positioning teeth. Such an orthodontic system may include a series of orthodontic aligners, each comprising a shell having one or more cavities shaped to receive at least a portion of a tooth. The aligners may be worn sequentially by a patient to move one or more teeth from a first row to a second row. One or more of the aligners may be segmented and may include connectors connecting the segments, as described herein.

[0009] Turning now to the drawings, FIG. 1 illustrates an exemplary tooth repositioning device or orthodontic aligner 100 that may be worn by a patient to achieve gradual repositioning of individual teeth 102 in the jaw. The orthodontic aligner 100 may comprise a shell (e.g., a continuous translucent polymeric shell or a segmented shell) having a tooth-receiving cavity that receives and resiliently repositions the teeth 102. The orthodontic aligner 100, or a portion thereof, may be indirectly manufactured using a physical model or mold of the teeth 102. For example, the aligner may be molded using a physical model of the teeth 102 and a sheet of appropriate layers of polymeric material. In some cases, the aligner 100 is manufactured directly from a digital model of the aligner, for example, using rapid prototyping techniques. The aligner 100 may fit all of the teeth 102 present in the upper or lower jaw, or may fit less than all of the teeth 102. The aligner 100 can be specifically designed to receive the patient's teeth (e.g., the surface shape of the tooth-receiving cavity matches the surface shape of the patient's teeth) and can be manufactured based on a positive or negative model of the patient's teeth created by impression, scanning, etc. Alternatively, the aligner 100 can be a general aligner configured to receive teeth, but not necessarily shaped to match the surface shape of the patient's teeth.

[0010] In some cases, only certain teeth received by the aligner are repositioned by the aligner while other teeth can provide base or anchor areas to hold the appliance in a fixed position when applying force against the tooth or teeth targeted for repositioning. In some cases, many or more, and even all, of the teeth are repositioned at some points during treatment. The moved teeth can also function as bases or anchors to hold the aligner when worn by the patient. Typically, no wire or other techniques are provided to hold the aligner in a fixed position on the teeth. In some cases, however, it may be preferable to provide individual attachments or other anchoring elements (not shown) on the teeth 102 with corresponding receivers or openings (not shown) in the orthodontic aligner 100 so that the aligner can apply selected forces to the teeth.

[0011] As shown, the orthodontic aligner 100 includes a first segment 105 and a second segment 110 separated by a connector 115. In the illustrated example, the first segment 105, the second segment 110, and the connector 115 are all part of a single continuous plastic body or shell. There may be a gap or space between the first segment 105 and the second segment 110, which may be maintained by the connector 115. However, the portion of the aligner 100 that includes the connector 115 may have less rigidity and / or more flexibility than the first segment 105 and the second segment 110. Alternatively or additionally, the geometry of the connector 115 may be configured to provide no or no contact with certain portions of one or more teeth. For example, the connector 115 may not contact the labial side of the anterior teeth (across which the connector 115 spans). The lower stiffness, higher flexibility, and / or geometry is a result of the aligner being cut to reposition the portion of the aligner 100 that covered the buccal regions of the patient's anterior teeth. The reduced stiffness, higher flexibility, and / or geometry of the aligner 100 at the connector 115 serves to isolate, reduce, or eliminate force transmission between the first segment 105 and the second segment 110. For example, because the aligner was cut to not cover the buccal regions of the anterior teeth, lingual forces cannot be applied to these anterior teeth. It can ensure that no distal forces are applied to the anterior teeth even when the posterior teeth covered by the first segment 105 and the second segment 110 are exposed to distal movement forces.

[0012] As a non-limiting example, each of the illustrated segments 105, 110 receives multiple teeth. However, in some cases, the segments may be configured to receive only a single tooth. In additional embodiments, an orthodontic aligner may include segments spanning a single tooth, segments spanning multiple teeth, as well as various combinations of these. In an aligner structure, the segments spanning a single tooth, as well as segments spanning multiple teeth, may include locations selected in the appliance design, rather than being limited to some specific location within the arch.

[0013] Connector 115 may be permanently fixed to shell segments 105, 110 such that shell segments 105, 110 cannot be non-destructively detached from one another. Alternatively, connector 115 may be detachable from shell segments 105, 110. In one embodiment, connector 115 provides protection against choking hazards that may be posed by the segments when separated.

[0014] 2 illustrates a segmented plastic orthodontic aligner 200 according to another embodiment. Similar to aligner 100, aligner 200 comprises a first segment and a second segment 210 joined by a connector 215. As with aligner 100, connector 215 in aligner 200 is formed by removing a portion of the body of aligner 200. However, in aligner 200, the portion of the aligner that contacts the lingual or labial regions of the patient's anterior teeth is cut off. Thus, the transmission of buccal forces to the anterior teeth can be avoided. Such forces can be avoided for the anterior teeth even in instances where forces are applied to the posterior teeth.

[0015] FIG. 3 illustrates a segmented plastic orthodontic aligner 300 according to another embodiment. The aligner 300 comprises a first segment 305, a second segment 310, and a third segment 315. The first segment 305 and the third segment 315 are joined by a first connector 320. Similarly, the second segment 310 and the third segment 315 are joined by a second connector 325. The first connector 320 and the second connector 325 can be elastomers (e.g., elastomeric adhesives), semi-rigid materials including thermoset and thermoplastic materials, semi-rigid metal connectors, and the like. In one embodiment, the first connector 320 and the second connector 325 are elastomers having a Shore hardness of A20 to A80 and an elastic modulus of about 100 square inches (psi) to about 100,000 psi. In one embodiment, the first connector 320 and the second connector 325 are semi-rigid thermosetting and thermosetting materials with a Shore hardness of D30 to D80 and an elastic modulus of about 100,000 psi to about 350,000 psi. In one embodiment, the first connector 320 and the second connector 325 are made of metal (e.g., metal wire, metal ribbon, etc.). In one embodiment, the connectors 320, 325 are molded with an elastic adhesive (e.g., elastomeric adhesive) that effectively constrains the segments with an elastic constraint. In another embodiment, the connectors 320, 325 are molded from polyurethane elastomer (PTE). In another embodiment, the connectors 320, 325 are molded from plastic, metal (e.g., archwire), and / or other materials. The connectors 320, 325 can be elastic, fully rigid, can be pivotally coupled, and / or can be coupled with a geometry that transmits a directional force without transmitting other forces.

[0016] The connectors 320, 325 may be molded from a single material or from multiple materials. The materials may be arranged in one or more layers. For example, layers of different materials or layers of the same material may be used to mold the connectors 320, 325. The properties of the material used to mold the connectors 320, 325, such as resilience, elasticity, hardness / softness, color, etc., may be determined, at least in part, based on the selected material, material shape, material dimensions, material layers, and / or material thickness. In one embodiment, the connectors 320, 325 are molded from a resilient material, such as an elastomeric material.

[0017] In some cases, the connectors 320, 325 may be configured such that one or more characteristics are uniform along a length or portion of the connector. Additionally, one or more characteristics of the connector may vary along a length or portion of the connector. For example, the connectors 320, 325 may have a substantially uniform thickness along a length or portion, or may vary along a length or portion. As will be appreciated, the characteristics of the connectors may be selected to reduce or eliminate the transmission of forces between different segments of the aligner and / or between groups of teeth.

[0018] In the illustrated exemplary aligner 300, the connectors 320, 325 operate to reduce or eliminate the transmission of forces between the patient's left and right posterior and anterior teeth. This allows the posterior teeth to be moved distally as a unit while separation movements can be made on the anterior teeth (e.g., to the patient's incisors). Alternatively, a mesial force can be applied to the posterior teeth without exerting a mesial force on the anterior teeth. Treatment of the posterior teeth will not affect or interfere with treatment of the posterior teeth. Similarly, treatment of the posterior teeth will not affect or interfere with treatment of the anterior teeth.

[0019] 4 illustrates a segmented plastic orthodontic aligner 400 according to another embodiment. The aligner 400 comprises a first segment 405 coupled to a second segment 410 by a bridge-like connector 415. The connector 415 is a semi-rigid material that is more flexible than transmitting forces between the first and second segments 405, 410. The connector 415 may be a pre-molded connector, or may be glued or mechanically attached to the segments.

[0020] In one embodiment, the segments 405, 410 each include retention features sized and shaped to retain an end of the connector 415. For example, the connector 415 can snap into place in the features. These features can be designed into the aligner 400. For example, these features can be included in a mold used to mold the aligner such that the aligner includes the features. Alternatively, these features can be molded (e.g., cut) into the segments and / or attached to the segments after they are molded. Some examples of retention features include grooves, ridges, protrusions, indentations, male or female mechanical snaps or locks, etc. Retention features can be used to prevent accidental dislodging or release of the connector 415 from a desired position, thereby ensuring that the aligner 400 does not come apart or become a choking hazard.

[0021] FIG. 5 illustrates a plastic orthodontic aligner 500 according to another embodiment. The aligner 500 comprises a first segment 505 coupled to a first side of a third segment 515 by a first connector 520. The aligner 500 additionally comprises a second segment 510 coupled to a second side of the third segment 515 by a second connector 525. The first and second connectors 520, 525 are wavy connectors having an accordion-like shape. The wavy shape will bend before applying clinically significant forces between the segments. Thus, the wavy shapes between the segments reduce the forces transmitted between the segments during treatment. In one embodiment, the wavy connectors 520, 525 are molded from the same material as the segments 505-515 (e.g., elastomer). In one embodiment, as shown, the connectors 520, 525 and the segments 505-515 form a single continuous shell body. Alternatively, the connectors 520, 525 may be separate elements attached to the segments 505-515. In such a case, the connectors 520-525 may be of the same material as the segments or of a different material. For example, the connectors 520-525 may be molded of an elastomer.

[0022] FIG. 6 illustrates a set of plastic orthodontic aligners designed to apply force to the upper posterior teeth without applying force to the upper anterior teeth, according to another embodiment. The set of aligners includes an upper aligner 608 and a lower aligner 605. The lower aligner 605 is a conventional non-segmented aligner with a retention feature 630. As shown, the retention feature 630 may be provided on the molars or other posterior teeth. The retention feature may be a slit, notch, groove, protrusion, or other shape that may secure one end of an elastic band 635 (e.g., a rubber band). Alternatively, the lower aligner 605 may include discontinuities such as notches, flaps, holes (e.g., openings, windows, gaps, notches, etc.) rather than retention features. The retention features may thus be directly restrained to the patient's teeth at the locations of the discontinuities. The discontinuities may expose the retention features when the lower aligner 605 is worn by the patient.

[0023] The upper aligner 605 is a segmented aligner comprising a first segment 610 and a second segment 615 joined by a connector 620. The first segment 610 comprises a retention feature 625 for securing a second end of an elastic band 635. As shown, the retention feature 625 may be provided on a canine or other anterior tooth. Alternatively, the first segment 610 may comprise a discontinuity such as a notch, flap, hole (e.g., an opening, window, gap, notch, etc.) rather than a retention feature. The retention feature may thus be restrained directly to the patient's tooth at the location of the discontinuity. The discontinuity may expose the retention feature when the upper aligner 608 is worn by the patient.

[0024] The elastic band 635 can apply a distal force to the first segment, and therefore to the group of teeth covered by the first segment 610. A similar elastic band can extend between the second segment 615 and the additional retention feature of the lower aligner 605 to apply a distal force to the second segment, and therefore to the group of teeth covered by the second segment 615. The connector 620 can isolate the force so that it is not applied to some of the patient's upper anterior teeth. In an alternative embodiment, the retention feature 625 can be provided on the upper posterior teeth and the retention feature 630 can be provided on the lower anterior teeth. In such a configuration, a mesial force can be applied to the second segment 615 without being applied to the first segment 610.

[0025] In alternative examples, the upper and / or lower aligners can be some of the segmented aligners described herein. For example, the upper aligner can be similar to aligner 300 of FIGURE 3 and can comprise three segments joined by two connectors, rather than two segments joined by a single connector.

[0026] The appliances described herein can be used in combination with one or more fixtures provided on one or more receiving teeth. Thus, the surface shape of the shell segments can be modified to accommodate the fixtures (with appropriate receptacles for receiving the fixtures). The fixtures can engage the shell segments and / or elastics to transmit repositioning forces to the underlying teeth as previously described herein. Alternatively or additionally, fixtures can be used to hold the appliance on the patient's teeth and prevent the appliance from being inadvertently removed. For example, teeth with natural implants (e.g., molars) may not require fixtures, while teeth without implants (e.g., central teeth, lateral teeth) may require fixtures to ensure correct engagement of the fixtures on the teeth. The fixtures can be provided on any suitable portion of the tooth, such as the buccal or lingual surface of the tooth.

[0027] FIG. 7 illustrates a flow diagram of one embodiment for a method 700 of orthodontic treatment using a series of aligners. Method 700 can be performed using any aligner or set of aligners described herein. In block 710, a first orthodontic aligner is placed on the patient's teeth to reposition the teeth from a first tooth alignment to a second tooth alignment. The patient's teeth are aligned such that different forces are applied to the teeth by different segments. These forces are inconsistent with conventional aligners because reaction forces from some segments can act as undermine forces to be applied to the teeth by other segments.

[0028] At block 720, a second orthodontic aligner is placed on the patient's teeth to reposition the teeth from the second tooth row to the third tooth row. Repositioning the teeth from the second tooth row to the third tooth row may be performed using a conventional aligner (e.g., a non-segmented aligner). Thus, a conventional non-segmented aligner may be used to reposition the teeth from the second tooth row to the third tooth row. Alternatively, the second orthodontic aligner may be another segmented aligner that isolates forces between different segments. The second orthodontic aligner may be segmented in a similar manner to the first orthodontic aligner or in a different manner than the first orthodontic aligner. For example, the first orthodontic aligner may include two segments separated by a single connector and the second orthodontic aligner may include a third segment each connected by a different connector. The different aligners may be segmented, for example, to apply forces to different groups of teeth.

[0029] The method 700 may be repeated using any suitable number and combination of aligners in order to gradually reposition the patient's teeth from the initial alignment to the target alignment. The aligners may all be produced in the same stage or in a set or batch (e.g., at the beginning of a stage of treatment) and the patient may wear each aligner until the pressure of each aligner on the teeth can no longer be felt or until the maximum of extruded tooth movement for a given stage has been achieved. A number of different aligners (e.g., a set) may even be designed and manufactured before the patient has worn several aligners. After wearing an aligner for an appropriate period of time, the patient may replace the current aligner with the next aligner in the series until they run out of aligners. The aligners are generally not fixed to the patient and the patient may provide and replace aligners at some time during the process (e.g., patient-removable aligners).

[0030] The final aligner or some aligners in the series may have a geometry or geometries selected to overcorrect the tooth alignment. For example, one or more aligners may have geometries that move individual teeth beyond the tooth alignment selected as "final" (if fully achieved). Such overcorrection may be desirable to offset potential reversals (e.g., allow individual teeth to move back toward pre-corrected positions) after the repositioning method is completed. Overcorrection may also be desirable to increase the speed of correction (e.g., aligners with geometries positioned beyond desired intermediate and final positions may move individual teeth toward those positions at a faster rate). In such cases, use of the aligner may be terminated before the teeth reach the positions defined by the aligner. Overcorrection may also be deliberately performed to compensate for some inaccuracies or limitations of the aligner.

[0031] FIG. 8 illustrates a flow diagram of one embodiment for a method 800 of manufacturing a segmented aligner with connectors that isolate, reduce or eliminate force transmission between segments. In some embodiments, one or more operations of method 800 are performed by processing logic of a computing device. The processing logic may comprise hardware (e.g., circuitry, dedicated logic, programmable logic, microcode, etc.), software (e.g., instructions executed by a processing device), firmware, or a combination thereof. For example, one or more operations of method 800 may be performed by a computing device such as computing device 1101 of FIG. 11. Additionally, some operations may be performed by a manufacturing device based on instructions received from the processing logic. Some operations may alternatively be performed by a user.

[0032] At block 805 of method 800, the shape is determined from a mold of a dental arch for the patient. The shape may be determined by digitally planning an intermediate or final target arrangement of the patient's teeth and manufacturing a mold of the dental arch that reflects the intermediate or final target arrangement. Alternatively, the shape may be determined by taking an impression of the patient's arch and generating a mold from the impression. Thus, the mold or model may be generated from a dental impression or a scanning (e.g., of the patient's intraoral cavity, of a positive or negative model of the patient's intraoral cavity, or of a dental impression cast from the patient's intraoral cavity).

[0033] Aligner manufacturing or design may utilize one or more physical or digital representations of the patient's teeth. The representation of the patient's teeth may comprise a representation of the patient's teeth in their current arrangement and may further comprise a representation of the patient's teeth positioned in one or more stages. A treatment stage may include a desired or target arrangement of the patient's teeth, such as a desired final arrangement of the teeth. A treatment stage may also include one or more intermediate arrangements of the teeth (e.g., planned intermediate arrangements) representing the arrangement of the patient's teeth as they progress from a first arrangement (e.g., initial arrangement) toward a second or desired arrangement (desired final arrangement).

[0034] In one embodiment, a digital representation of the patient's teeth is received at block 808. The digital representation may include surface topography data for the patient's intra-oral cavity (including the teeth, gum tissue, etc.). The surface topography data may be generated by direct scanning of the intra-oral cavity, by a physical model (positive or negative) of the intra-oral cavity, or by an impression of the intra-oral cavity using a suitable scanning device (e.g., a handheld scanner, a desktop scanner, etc.).

[0035] In one embodiment, at block 809, one or more treatment stages are generated based on the digital representation of the teeth. The treatment stages may be gradual repositioning stages of an orthodontic procedure designed to move one or more of the patient's teeth from an initial alignment to a target alignment. For example, the treatment stages may be generated by determining an initial tooth alignment indicated by the digital representation, by determining a target tooth alignment, and by determining a movement path of one or more teeth in the initial alignment required to achieve the target tooth alignment. The movement path may be optimized based on minimizing the total movement distance, based on preventing collisions between teeth, based on avoiding tooth movements that are more difficult to achieve, or based on other suitable criteria.

[0036] At block 810, a mold is manufactured based on the determined shape. This may include using a three-dimensional virtual model of the dental arch and sending instructions to a rapid prototyping machine (e.g., a three-dimensional printer) to manufacture the mold. In one embodiment, the fragile mold is manufactured using a rapid prototyping technique. One example of a rapid manufacturing technique is three-dimensional printing. Three-dimensional printing involves several layer-based additive manufacturing steps. The three-dimensional printer can receive an input of a three-dimensional virtual model of the mold (e.g., as a computer-aided drafting (CAD) file or a three-dimensional printable file such as a stereolithography (STL) file) and can use the three-dimensional virtual model to generate the mold. Three-dimensional printing can be done in an additive process, where successive layers of material are molded in the prescribed shape. Three-dimensional printing can be done using extrusion deposition, granular binding, lamination, photopolymerization, or other techniques.

[0037] In one embodiment, stereolithography (SLA), also known as optical fabrication solid imaging, is used to fabricate the SLA mold. In SLA, the mold is fabricated by successively printing thin layers of a photocurable material (e.g., polymeric resin) on top of one another. A platform rests in a bath of liquid photopolymer or in the resin just below the surface of the bath. A light source (e.g., an ultraviolet laser) traces a pattern on the platform to mold the first layer of the mold, curing the photopolymer at which the light source is directed. The platform is gradually lowered, and the light source traces a new pattern on the platform to mold the other layers of the mold at each stage. This process is repeated until the mold is completely fabricated. Each layer can be between 25 microns and 200 microns thick. Once all of the layers of the mold are fabricated, the mold can be washed and cured.

[0038] At block 815, a plastic orthodontic aligner is formed in the mold. This may include sending instructions to a pressure forming or thermoforming device to pressure form or thermoform a sheet of material in the mold to form the body of the aligner. The sheet may be, for example, a sheet of plastic (e.g., a thermoplastic). To thermoform the shell or aligner in the mold, the sheet of material may be heated to a temperature at which the sheet becomes pliable. Pressure may be simultaneously applied to the sheet to form the now pliable sheet around the frangible mold. When the sheet cools, it has a shape that matches the mold. In one embodiment, a release agent (e.g., a non-stick material) is applied to the mold prior to forming the aligner. This may facilitate later removal of the mold from the aligner. The plastic orthodontic aligner may include a first segment and a second segment that are molded together (e.g., molded together). In some embodiments, a connector may also be molded together in the arrangement of the first and second segments.

[0039] Other exemplary methods for manufacturing the aligner or separation segments and / or connectors of the aligner include rapid prototyping, stereography, or computer numerical control (CNC) milling. The material of the aligner or shell segments can be translucent, such as a translucent polymer.

[0040] At block 820, the plastic orthodontic aligner is cut to separate the aligner into at least two segments separated by a connector. This may include sending commands to a cutting tool to cause the cutting tool to cut the aligner at specific coordinates. The cutting tool may be, for example, a laser cutter, a plasma cutter, or a mill. The at least two segments and the connector are part of a single continuous plastic body. Each single shell segment includes one or more cavities shaped to receive at least a portion of a tooth. The shell segments can collectively receive a continuous length of the tooth. The number and shape of the shell segments can be selected to tailor the desired tooth movement, and the connectors can isolate forces to allow different tooth movements to different sets of teeth. The aligner may also be marked and / or trimmed along the gingival cut line.

[0041] A set of aligners can be manufactured, each shaped to accommodate the tooth alignment identified by one of the treatment stages, such that the aligners can be worn sequentially by the patient to gradually reposition the teeth from an initial alignment to a target alignment. The set of aligners can comprise one or more segmented aligners as described herein. The characteristics (e.g., number, geometry, configuration, material properties) of the shell segments and connectors of such segmented aligners can be selected to elicit the tooth movement identified by the corresponding treatment stage. At least some of these characteristics can be determined by suitable computer software or a digitally based approach. Manufacturing the aligners can include generating a digital model of the aligner to be used as input to a computer controlled manufacturing system.

[0042] FIG. 9 illustrates a flow diagram of another embodiment for a method 900 of manufacturing a segmented aligner with connectors that isolate force transmission between segments. In some embodiments, one or more operations of the method 900 are performed by processing logic of a computing device. The processing logic may comprise hardware (e.g., circuitry, dedicated logic, programmable logic, microcode, etc.), software (e.g., instructions executed by a processing device), firmware, or a combination thereof. For example, one or more operations of the method 900 may be performed by a computing device such as computing device 1101 of FIG. 11. Additionally, some operations may be performed by a manufacturing device based on instructions received from the processing logic. Some operations may alternatively be performed by a user (e.g., based on user interaction with a mold modeling module or a drafting program).

[0043] At block 905 of method 900, a shape is determined for a mold of a dental arch for a patient. The shape is determined by digitally planning an intermediate or final target arrangement of the patient's teeth and digitally manufacturing a mold of the dental arch that reflects the intermediate or final target arrangement. Alternatively, the shape may be determined by taking an impression of the patient's arch and generating the mold from the impression. At block 910, the mold is manufactured based on the determined shape (based on sending instructions to a rapid prototyping machine). This may include using a three-dimensional virtual model of the dental arch and a rapid prototyping machine (e.g., a three-dimensional printer) to manufacture the mold.

[0044] At block 915, a plastic orthodontic aligner is formed in the mold (based on sending instructions to a pressure forming or thermoforming device). In one embodiment, the plastic orthodontic aligner is pressure formed or thermoformed in the mold. Other exemplary methods for manufacturing the aligner or separation segments and / or connectors of the aligner include rapid prototyping, stereolithography, or computer numerical control (CNC) milling. The material of the aligner or shell segments can be translucent, such as a translucent polymer. Alternatively, the material can have any other desired color or colors.

[0045] At block 920, the plastic orthodontic aligner is cut (e.g., based on sending instructions to a cutting tool) to separate the aligner into at least two segments separated by a connector. The aligner may be cut using a laser cutter, a plasma cutter, a mill, or a mechanical cutter. The aligner is cut to separate the aligner into multiple separate segments that are not connected.

[0046] At block 925, the separate shell segments are joined using a connector (or multiple connectors), thus forming a single aligner shell. In one embodiment, commands are sent to the device to cause it to join the segments to the connectors. Alternatively, prompts can be output to a display to instruct the user to manually connect the segments to the connectors. The connectors can be an elastic material. Alternatively, the connectors can be plastic, such as semi-rigid plastic. Other elastic or semi-rigid materials can also be used. In many embodiments, the connectors are translucent. The connectors can be strips, bands, sheets, meshes, coatings, layers, tubes, elastic adhesives, or suitable combinations thereof, and can be manufactured from any suitable material. Exemplary manufacturing methods for elastic materials include extrusion, rapid prototyping, spraying, thermoforming, or suitable combinations thereof. The properties of the connectors (e.g., length, width, thickness, area, shape, cross-section, stiffness) can be homogenous or can vary throughout the bulk of the elastic material. For example, different portions of the connector can have different thicknesses, which changes the local compliance of the aligner. Also, in some cases, the connector can have anisotropic properties. As an example, the connector can be relatively compliant along a first direction and less compliant (or not compliant) along a second direction. The directional flexibility of the connector can be used to reduce the transmission of forces between the teeth while providing structure and security to the aligner.

[0047] The connectors may be bonded to the segments using a suitable adhesive or restraining agent. In some cases, the connectors may have adhesive properties, thus allowing the connectors to be bonded directly to the shell segments without the use of additional topical agents. Exemplary methods of providing the connectors to the shell segments include extrusion, spraying, coating, dipping, or suitable combinations thereof. The connectors may also be physically connected to the segments using snaps, claps, locks, and the like. For example, the connectors may have male ends of snaps, and the retention features on the segments may have female ends of snaps. In one embodiment, additional information may be sent to one or more devices to cause the devices to mold the retention features on the segments. The retention features may be for holding elastic bands that may later be provided to the retention features and to other retention features on other aligners, segments of aligners, or teeth. In one embodiment, molding the retention features includes cutting slits or grooves in the segments of the aligner.

[0048] FIG. 10 illustrates a flow diagram of another embodiment for a method of manufacturing a segmented aligner with connectors that isolate, reduce or eliminate force transmission between segments. In some embodiments, one or more operations of method 1000 are performed by processing logic of a computing device. The processing logic may comprise hardware (e.g., circuitry, dedicated logic, programmable logic, microcode, etc.), software (e.g., instructions executed by a processing device), firmware, or a combination thereof. For example, one or more operations of method 1000 may be performed by a computing device such as computing device 1101 of FIG. 11. Additionally, some operations may be performed by a manufacturing device based on instructions received from the processing logic. Some operations may alternatively be performed by a user (e.g., in a mold modeling module or a drafting program).

[0049] At block 1005 of method 1000, a shape is determined for a first mold of a first dental arch and for a second mold of a second portion of the dental arch. The first mold may represent a first set of the patient's teeth and the second mold may represent a second set of the patient's teeth. The shape may be determined by digitally planning an intermediate or final target arrangement of the patient's teeth. Alternatively, the shape may be determined by taking an impression of the patient's arch. At block 1010, a mold is manufactured based on the determined shape. This may include using a three-dimensional virtual model of the dental arch and a rapid prototyping device (e.g., a three-dimensional printer) to manufacture the mold.

[0050] At block 1015, a first segment of a plastic orthodontic aligner is formed in a first mold. In one embodiment, the first segment of the plastic orthodontic aligner is thermoformed or pressure formed in the mold. At block 1020, a second segment of the plastic orthodontic aligner is formed in a second mold. Exemplary methods for manufacturing the segments include thermoforming, rapid prototyping, stereolithography, or computer numerical control (CNC) milling.

[0051] At block 1025, the separate shell segments are joined using a connector (or multiple connectors) to form a unitary aligner shell. The connector can be an elastic material. Alternatively, the connector can be a plastic, such as a semi-rigid plastic. Other elastic or semi-rigid materials can also be used.

[0052] 11 is a schematic block diagram of a system 1100 that may be used in performing the methods and processes described herein. The system 1100 typically includes a computing device 1101, a scanner 1120, and / or a manufacturing device 1122 connected to a network 1124. The computing device 1101 may be connected (e.g., networked) to other devices in a local network (LAN), an intranet, an extranet, or the Internet. For example, the computing device 1101 may be networked to a manufacturing device 1122, which may be a rapid prototyping device such as a 3D printer or an SLA device. The computing device 1101 may operate in the capacity of a server or client device in a client-server network environment, or may operate as a peer device in a peer-to-peer (or distributed) network environment. Computing device 1101 may be a personal computer (PC), a tablet computer, a set-top box (STB), a personal digital assistant (PDA), a mobile phone, a web application, a server, a network router, switch or bridge, or any other device capable of executing a set of instructions that specify actions to be performed by the device (either serially or otherwise). Also, although only a single device is illustrated, the term computing device should also be interpreted to include any collection of devices (e.g., computers) that individually or in conjunction execute a set (or multiple sets) of instructions to perform one or more of the methods described herein.

[0053] Computing device 1101 includes at least one processing unit 1102 that communicates with one or more peripheral devices via bus subsystem 1104. Processing unit 1102 represents one or more general purpose processors, such as a microprocessor, a central processing unit, or the like. In particular, processing unit 1102 may be a complex instruction set computing (CISC) microprocessor, a reduced instruction set computing (RISC) microprocessor, a very long instruction word (VLIW) microprocessor, a processor implementing other instruction sets, or a processor implementing a combination of instruction sets. Processing unit 1102 may also be one or more special purpose processing units, such as an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a digital signal processor (DSP), a network processor, or the like. Processing unit 1102 is configured to execute processing logic (instructions) for performing the operations and steps described herein.

[0054] Peripheral devices typically connected to the processing unit 1102 include a storage subsystem 1106 (a memory subsystem 1108 and a file storage subsystem 1114), a set of user interface input and output devices 1118, and an interface to an external network 1116. This interface is shown diagrammatically as a "network interface" block 1116, and is connected to corresponding interface devices in other data processing systems via a communications network interface 1124.

[0055] User interface input devices 1118 are not limited to any particular device and may typically comprise, for example, a keyboard, a pointing device, a mouse, a scanner, an interactive display, a touchpad, a joystick, etc. Similarly, a variety of user interface output devices may be employed in the inventive system, which may include, for example, one or more printers, display (e.g., visual, non-visual) systems / subsystems, controllers, projection devices, audio outputs, etc.

[0056] The storage subsystem 1106 comprises a computer-readable medium that manages the basic programming of the computing device 1101 and that contains instructions (e.g., operating instructions, etc.) and data structures. Program modules described herein are typically stored in the storage subsystem 1106. The storage subsystem 1106 typically comprises a memory subsystem 1108 and a file storage subsystem 1114. The memory subsystem 1108 typically comprises a number of memories (e.g., RAM 1110, ROM 1112, etc.) that include computer-readable memory for storage of fixed instructions, instructions and data during program execution, basic input / output systems, etc. The file storage subsystem 1114 comprises permanent (non-volatile) storage for program and data files and may comprise one or more readable or fixed devices or media, hard disks, floppy disks, CD-ROMs, DVDs, optical devices, etc.

[0057] The file storage subsystem 1114 may comprise a device-readable storage medium (or, more specifically, a non-volatile computer-readable storage medium) on which one or more sets of instructions employing one or more of the techniques or functions described herein are stored. A non-volatile storage medium refers to a storage medium other than a carrier wave. The instructions may reside, completely or at least partially, within the memory subsystem 1108 and / or within the processing unit 1102 during processing by the computing device 1101, the memory subsystem 1108, and the processing unit 1102, which also include computer-readable storage media.

[0058] The computer readable storage medium may also be used to store one or more virtual 3D model and / or segmented aligner generation modules 1150 that may perform one or more operations of the methods 800-1000 described with respect to Figures 8-10. The term "computer readable storage medium" should be understood to include a single medium or multiple media (e.g., a centralized or distributed database and / or associated caches and servers) that store one or more sets of instructions. The term "computer readable storage medium" should also be understood to include any medium other than a carrier wave that is capable of storing or encoding a set of instructions for execution by a device that causes the device to perform one or more of the techniques of the present invention. The term "computer readable storage medium" should therefore be understood to include, but is not limited to, solid-state memories and optical and mechanical media.

[0059] One or more storage systems, drives, etc. may be provided at remote locations, such as connected via a server in a network or via the Internet / World Wide Web. As used herein, the term "bus system" is used broadly to include any mechanism for allowing the various elements and subsystems to communicate with each other as intended, and may comprise any suitable element / system known or recognized as suitable for use herein. It is to be understood that the various elements of the system need not necessarily be in the same physical location, but may be connected via various local or wide area network mediums, transmission systems, etc.

[0060] The scanner 1120 includes several techniques for acquiring a digital representation (e.g., images, surface topography data, etc.) of the patient's teeth (e.g., by scanning a physical model of the teeth such as a cast, by scanning an impression taken of the teeth, or by directly scanning the patient's oral cavity). The scanner 1120 can receive and generate dental arch data 1121 (which can be data usable to generate a three-dimensional virtual model of the patient's dental arch) and can provide such dental arch data 1121 to the computing device 1101. The scanner 1120 can be located remotely with respect to other elements of the system and can communicate image data and / or information to the computing device 1101, for example, via a network interface 1124. The manufacturing system 1122 manufactures orthodontic aligners 1123 based on the treatment plan, which includes the data set information received from the computing device 1101. The manufacturing device 1122 can be located remotely, for example, and can receive the data set information from the computing device 1101 via a network interface 1124.

[0061] It is to be understood that the foregoing is intended to be illustrative, and not restrictive. Numerous other embodiments will clarify the reading and understanding of the above. Although embodiments of the present invention have been described with reference to certain exemplary embodiments, it will be understood that the invention is not limited to the described embodiments, but that modifications and alternatives can be made within the spirit and scope of the appended claims. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense. The scope of the invention should therefore be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

[0062] [Appendix 1] molding a first segment of a plastic orthodontic aligner for moving a first set of the patient's teeth; molding a second segment of the plastic orthodontic aligner; coupling the first segment of the plastic orthodontic aligner to the second segment of the plastic orthodontic aligner with a connector configured to minimize force transmission between the first segment and the second segment; The method includes: [Appendix 2] The step of molding the first segment of the plastic orthodontic aligner comprises: generating a first mold of a first portion of a dental arch including a model of the first set of teeth; and thermoforming or pressure forming the first segment into the first mold; The step of molding the second segment of the plastic orthodontic aligner comprises: generating a second mold of a second portion of the dental arch including a model of a second set of teeth; and thermoforming or pressure forming the second segment into the second mold. The method described in Appendix 1. [Appendix 3] The steps of molding the first segment and molding the second segment include: generating a mold of the patient's dental arch; thermoforming or pressure forming plastic in the mold to form the plastic orthodontic aligner; cutting the plastic orthodontic aligner to separate the plastic orthodontic aligner into the first segment and the second segment; carried out together in a process comprising: The method described in Appendix 1. [Appendix 4] the connector includes an elastic adhesive constraining the first segment at a first end and the second segment at a second end; The method described in Appendix 1. [Appendix 5] the connector is for minimizing the transmission of forces in a first direction without minimizing the transmission of forces in a second direction; The method described in Appendix 1. [Appendix 6] a first plastic segment having a first shape that conforms to a first portion of a patient's dental arch, the first plastic segment configured to apply a force to a first set of teeth in the first portion of the dental arch; and a second plastic segment having a second shape that conforms to a second portion of the patient's dental arch; and a connector coupling the first plastic segment to the second plastic segment, the connector being for minimizing the transmission of forces between the first plastic segment and the second plastic segment; and An orthodontic aligner comprising: [Appendix 7] the connector is for minimizing the transmission of forces in a first direction without minimizing the transmission of forces in a second direction; 11. An orthodontic aligner as described in appended claim 6. [Appendix 8] the connector comprises at least one of a semi-rigid thermoset, a semi-rigid thermoplastic, or a semi-rigid metal; 11. An orthodontic aligner as described in appended claim 6. [Appendix 9] the first segment, the second segment, and the connector are part of a single continuous plastic body. 11. An orthodontic aligner as described in appended claim 6. [Appendix 10] the orthodontic aligner is configured to apply a first spacing force to a first set of teeth at the first portion of the dental arch via the first segment and a second spacing force to a second set of teeth at the second portion of the dental arch via the second segment. 11. An orthodontic aligner as described in appended claim 6. [Appendix 11] the connector is configured to span a gap between the first segment and the second segment, the gap corresponding to the position of one or more additional teeth in the dental arch that are not intended to be subjected to clinically significant forces; 11. An orthodontic aligner as described in appended claim 6. [Appendix 12] the connector comprises a corrugated shape for bending prior to application of a force between the first plastic segment and the second plastic segment. 11. An orthodontic aligner as described in appended claim 6. [Appendix 13] one or more additional segments, the one or more additional segments having additional shapes to fit over additional portions of the patient's dental arch; and one or more additional connectors coupling the one or more additional segments to at least one of the first segments to the second segments. 11. An orthodontic aligner as described in appended claim 6. [Appendix 14] a retention feature on the first plastic segment configured to receive an elastic band for applying one of a distal force or a mesial force to the first set of teeth without applying a force to the patient's second set of teeth. 11. An orthodontic aligner as described in appended claim 6. [Appendix 15] the first plastic segment has a first shape configured to hold a first end of the connector, and the second plastic segment has a second shape configured to hold a second end of the connector. 11. An orthodontic aligner as described in appended claim 6. [Appendix 16] A non-transitory computer-readable storage medium storing instructions that, when executed by a processor, receiving, by the processing device, a digital three-dimensional model of a patient's dental arch; the processing device sending first instructions to a rapid prototyping device to cause the rapid prototyping device to generate a physical mold of the dental arch based on the digital three-dimensional model; after the physical mold is formed, sending second instructions to the thermoforming or pressure forming device to generate an orthodontic aligner based on thermoforming or pressure forming a plastic sheet into the physical mold; sending third instructions to a cutting tool by the processing device to cause the cutting tool to cut the orthodontic aligner into at least a first segment and a second segment, the cutting tool applying a force to a first set of anterior teeth of the patient's dental arch to the second segment without applying any force to a second set of posterior teeth of the patient's dental arch; causing the processing device to perform operations including A non-transitory computer-readable storage medium. [Appendix 17] The operation comprises: sending a command to provide a connector between the first segment and the second segment, the connector for isolating forces between the first segment and the second segment; 17. A non-transitory computer-readable storage medium as described in claim 16. [Appendix 18] the digital three-dimensional model comprises a first shape that causes a first segment to have a first retention shape configured to hold a first end of the connector, and a second shape that causes a second segment to have a second retention shape configured to hold a second end of the connector. 18. A non-transitory computer-readable storage medium as described in claim 17. [Appendix 19] the third instruction causes a portion of the orthodontic aligner between the first segment and the second segment to be a connector between the first segment and the second segment that isolates forces between the first segment and the second segment. 17. A non-transitory computer-readable storage medium as described in claim 16. [Appendix 20] The operation comprises: sending a fourth command to the device to cause the device to mold a retaining shape in the first plastic segment configured to receive an elastic band for applying a distal force to the first set of teeth without applying a force to a second set of teeth of the patient. 17. A non-transitory computer-readable storage medium as described in claim 16.

Claims

1. A set of removable orthodontic aligners, A first orthodontic aligner for fitting to a first dental arch of the patient, the first dental arch being either an upper dental arch or a lower dental arch of the patient, a first plastic segment having a first shape to fit over a first posterior portion of the patient's first dental arch, the first plastic segment configured to apply a first force to a first set of teeth in the first posterior portion of the first dental arch; a second plastic segment having a second shape that fits over a second posterior portion of the patient's first dental arch; and a connector disposed between the first plastic segment and the second plastic segment and shaped to conform to a lingual side of one or more additional teeth along an anterior portion of the first dental arch without exerting clinically significant forces on the one or more additional teeth of the patient, the connector spanning the one or more additional teeth in a gap between the first plastic segment and the second plastic segment, the gap corresponding to the one or more additional teeth that are not subjected to the clinically significant forces; the first orthodontic aligner, the first plastic segment having a first retention shape and the second plastic segment having a second retention shape; a second orthodontic aligner for fitting to a second dental arch of the patient, the second dental arch being an opposing dental arch to the first dental arch, the second orthodontic aligner having a first retention shape and a second retention shape; Equipped with a first elastic band configured to connect the first orthodontic aligner and the second orthodontic aligner, a first end of the first elastic band being connected to the first retention feature of the first plastic segment of the first orthodontic aligner and a second end of the first elastic band being connected to the first retention feature of the second orthodontic aligner; a second elastic band configured to connect the first orthodontic aligner and the second orthodontic aligner, a first end of the second elastic band being connected to the second retention feature of the second plastic segment of the first orthodontic aligner and a second end of the second elastic band being connected to the second retention feature of the second orthodontic aligner; A set of removable orthodontic aligners.

2. 10. The set of removable orthodontic aligners of claim 1, wherein the first plastic segment, the second plastic segment, and the connector are parts of a single continuous plastic body.

3. 10. The set of removable orthodontic aligners of claim 1, wherein the connectors comprise at least one of an elastomer, a semi-rigid thermoset, or a semi-rigid thermoplastic, the connectors comprising a plastic material that at least one of bends, moves, and changes shape in response to an applied force.

4. A set of removable orthodontic aligners as described in claim 1, wherein the second plastic segment is configured to apply a second force to a second set of teeth in the second posterior portion of the first dental arch, and the connector is configured to isolate the first force applied to the first set of teeth from the second force applied to the second set of teeth.

5. forming a first orthodontic aligner for fitting to the first dental arch of the patient, the first plastic segment having a first shape to fit over a first posterior portion of a first dental arch of the patient, the first plastic segment configured to apply a first force to a first set of teeth in the first posterior portion of the first dental arch, and a second plastic segment having a second shape to fit over a second posterior portion of the first dental arch of the patient; cutting a portion of the first orthodontic aligner covering a buccal region of the anterior portion of the first dental arch to form a connector disposed between the first plastic segment and the second plastic segment and having a shape that conforms to a lingual side of one or more additional teeth along the anterior portion of the first dental arch without exerting clinically significant forces on one or more additional teeth of the patient, the connector spanning the one or more additional teeth in a gap between the first plastic segment and the second plastic segment, the gap corresponding to the one or more additional teeth that are not subjected to the clinically significant forces; forming a second orthodontic aligner for fitting to a second dental arch of the patient opposite the first dental arch, the second orthodontic aligner comprising (1) a first retention shape and a second retention shape, or (2) a first discontinuity and a second discontinuity; (a) a first elastic band configured to connect the first orthodontic aligner and the second orthodontic aligner, a first end of the first elastic band being connected to the first retention feature of the first plastic segment of the first orthodontic aligner and a second end of the first elastic band being connected to the first retention feature of the second orthodontic aligner; a second elastic band configured to connect the first orthodontic aligner and the second orthodontic aligner, a first end of the second elastic band being connected to the second retention feature of the second plastic segment of the first orthodontic aligner and a second end of the second elastic band being connected to the second retention feature of the second orthodontic aligner; or (b) the first elastic band is configured to couple the first orthodontic aligner and the second dental arch, the first end of the first elastic band being coupled to the first retention feature of the first plastic segment of the first orthodontic aligner and the second end of the first elastic band being coupled to a first retention feature coupled to a first tooth of the patient and exposed by the first discontinuity of the second orthodontic aligner when the second orthodontic aligner is worn by the patient; the second elastic band is configured to couple the first orthodontic aligner and the second dental arch, the first end of the second elastic band being coupled to the second retention feature of the second plastic segment of the first orthodontic aligner, and the second end of the second elastic band being coupled to a second retention feature coupled to a second tooth of the patient and exposed by the second discontinuity of the second orthodontic aligner when the second orthodontic aligner is worn by the patient. Manufacturing method.

6. The method of claim 5 , wherein the first plastic segment, the second plastic segment, and the connector are part of a single continuous plastic body.

7. The method of claim 5 , wherein the connector comprises at least one of an elastomer, a semi-rigid thermoset, or a semi-rigid thermoplastic.

8. 6. The method of claim 5, wherein the connector is configured to isolate the first force applied to the first set of teeth in the first posterior portion of the first dental arch from a second force applied to a second set of teeth in the second posterior portion of the first dental arch.

9. A computer readable storage medium comprising instructions which, when executed by a processor, cause the processor to perform the manufacturing method of any one of claims 5 to 8.

10. memory; and A processing unit coupled to said memory, said processing unit performing the method of any one of claims 5 to 8; A system comprising:

11. the first retention feature and the second retention feature comprise a notch; 10. The set of removable orthodontic aligners of claim 1.

12. the first retention feature and the second retention feature comprise a protrusion; 10. The set of removable orthodontic aligners of claim 1.

13. A set of removable orthodontic aligners, A first orthodontic aligner for fitting to a first dental arch of the patient, the first dental arch being either an upper dental arch or a lower dental arch of the patient, a first plastic segment having a first shape to fit over a first posterior portion of the patient's first dental arch, the first plastic segment configured to apply a force to a first set of teeth in the first posterior portion of the first dental arch; a second plastic segment having a second shape that fits over a second posterior portion of the patient's first dental arch; and a connector disposed between the first plastic segment and the second plastic segment and shaped to conform to a lingual side of one or more additional teeth along an anterior portion of the first dental arch without exerting clinically significant forces on the one or more additional teeth of the patient, the connector spanning the one or more additional teeth in a gap between the first plastic segment and the second plastic segment, the gap corresponding to the one or more additional teeth that are not subjected to the clinically significant forces; the first orthodontic aligner, the first plastic segment having a first retention shape and the second plastic segment having a second retention shape; a second orthodontic aligner for wear on a second dental arch of the patient, the second dental arch being an opposing dental arch to the first dental arch, the second orthodontic aligner comprising a first discontinuity and a second discontinuity; Equipped with a first elastic band configured to couple the first orthodontic aligner and the second dental arch, a first end of the first elastic band coupled to the first retention feature of the first plastic segment of the first orthodontic aligner, a second end of the first elastic band coupled to a first retention feature exposed by the first discontinuity of the second orthodontic aligner when the second orthodontic aligner is worn by the patient, the first retention feature being coupled to a first tooth of the patient; a second elastic band configured to couple the first orthodontic aligner and the second dental arch, a first end of the second elastic band coupled to the second retention feature of the second plastic segment of the first orthodontic aligner, a second end of the second elastic band coupled to a second retention feature exposed by the second discontinuity of the second orthodontic aligner when the second orthodontic aligner is worn by the patient, and the second retention feature coupled to a second tooth of the patient; A set of removable orthodontic aligners.

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