A standardizing measuring device for measuring the thickness of a transparent tooth cover and a method for manufacturing the same

Abstract

The application provides a standardizing measuring transparent tooth cover thickness calibration device and a preparation method thereof. The preparation method of the calibration device is based on a tooth row digital model corresponding to the transparent tooth cover, a measuring needle digital model of a needle type thickness gauge is obtained, a measuring point of the tooth row digital model or the tooth cover digital model is determined and labeled, a measuring direction is determined and labeled based on the measuring point, the measuring needle digital model is placed according to the measuring point and the measuring direction, a measuring needle navigation channel is created on the tooth row digital model according to a model part overlapped by the tooth row digital model and the measuring needle digital model, and finally the calibration device is completed. The calibration device is used for assisting in measuring the thickness of different points of the transparent tooth cover in a fixed point, a fixed direction and a fixed depth, so that accurate and repeatable measurement is realized.

Description

Technical Field

[0001] This invention belongs to the field of orthodontic instrument calibration technology, and relates to a standardized calibration device for measuring the thickness of clear braces and its preparation method. Background Technology

[0002] Clinically, patients often report that while membrane retainers are aesthetically pleasing, they are still not comfortable enough, mainly because they feel thick and hard after wearing them. Most literature indicates that poor patient compliance with retainers is primarily due to loss, discomfort, and speech impairment. Similarly, these issues also exist with different brands of clear aligners (hereinafter referred to as "membrane retainers" and "clear aligners").

[0003] The thickness of clear aligners significantly affects compliance and comfort. The thickness of the cusps and surfaces can affect occlusion, impacting functions such as swallowing and speech. The silver edge comes into contact with the gums and other oral mucosa, affecting the comfort of the clear aligners and causing sensations such as a foreign body feeling and nausea.

[0004] The thickness of clear aligners is primarily determined by the thickness of the fabricated diaphragm (typically 0.75–2 mm), and is also influenced by the dental arch model used during pressing and other manufacturing conditions (such as the placement angle of the dental arch model and the heating time of the diaphragm). Due to the irregular shape of clear aligners, it is difficult to define and measure their overall thickness. Current research focuses more on the thickness of the diaphragm itself before pressing, and there is no unified standard or method for measuring the thickness of the finished clear aligner. Existing literature describes measurement methods for clear aligners including spraying a special contrast agent onto the aligner surface and scanning it into a digital model using a desktop or intraoral scanner for measurement; manual measurement using an electronic digital thickness gauge; and surface measurement using a coordinate measuring machine and scanning probe.

[0005] The methods described above can be broadly categorized into two types: one involves scanning the braces into a digital model, and the other involves manual measurement using electronic measuring instruments. Both methods have their own problems: the reagents and instruments required for digital scanning are large and expensive, resulting in high purchase costs for primary healthcare institutions and high usage costs for patients; furthermore, the entire analysis process is time-consuming, making it more suitable for scientific research and not for widespread clinical use as a quality control method.

[0006] It should be noted that due to the transparent nature of clear aligners, it is very difficult to scientifically and accurately measure the thickness at fixed points using low-cost technologies such as conventional 3D scanning. On the one hand, conventional 3D scanning cannot directly scan the clear aligners to form a digital model; it usually requires powder spraying before scanning. The uniformity of powder spraying depends on the operator's experience, and the thickness of the powder layer is difficult to control and measure. On the other hand, the scanned aligner model also has a significant margin of error due to scanning accuracy issues.

[0007] When using manual measurement, the thinness of the braces necessitates high precision and a wide measurement range from the electronic thickness gauge. Furthermore, the irregular shape and semi-enclosed structure of the braces require a unique probe that can penetrate deep into the crown. During manual measurement using an electronic thickness gauge (Guanglu, Guangxi, China) (using a 0.75mm diaphragm vacuum-pressed transparent braces), we found that even with fixed measurement points on the tooth surface (marked with a marker), the space at the crown allows the probe to be swung left and right within a certain range around the measurement point, changing the measurement direction and angle. When the measurement direction and angle are uncertain, the measured data varies significantly and exceeds the acceptable error range (±0.02mm). Manually measured data shows large initial deviations that decrease later; currently, determining the measurement direction and angle relies heavily on researchers' experience accumulated through extensive measurements. Summary of the Invention

[0008] The purpose of this invention is to solve the problems in the background art mentioned above, and to provide a standardized calibration device for measuring the thickness of clear aligners and its preparation method. This calibration device is used to assist in measuring the thickness of clear aligners at different points by fixing the point, orientation, and depth, so as to achieve accurate and repeatable measurement. Its preparation method is simple and has good promotion benefits, and can provide useful guidance and assistance for the clinical use of clear aligners and pressure-film retainers.

[0009] To achieve the above objectives, the present invention employs a technical solution consisting of the following technical measures.

[0010] A method for preparing a standardized calibration device for measuring the thickness of clear aligners includes the following steps:

[0011] (1) Obtain a digital model of the clear braces and a digital model of the dentition corresponding to the clear braces;

[0012] Obtain the digital model of the measuring needle of the needle thickness gauge. The selected needle thickness gauge measures thickness using two measuring needles, one of which is L-shaped.

[0013] (2) Identify and label the measurement sites in the digital model of the dental arch or the digital model of the braces;

[0014] (3) Determine and mark the measurement direction based on the measurement sites obtained in step (2);

[0015] (4) Based on the measurement site and measurement direction, place the digital model of the measuring needle so that the digital model of the measuring needle presents a state in which the measurement site is measured in the measurement direction;

[0016] (5) Assemble the digital model of the braces and the digital model of the dental arch according to the conventional installation method of transparent braces, and create a measurement needle navigation channel on the digital model of the dental arch based on the overlapping part of the model of the digital model of the dental arch and the digital model of the measuring needle.

[0017] (6) Based on the digital model of the dental arch with a measuring needle navigation channel, the alignment device is made.

[0018] In this article, the digital model of the clear aligners can be obtained through the digital fabrication process of the clear aligners, or it can be obtained by modeling or 3D scanning based on an existing clear aligner.

[0019] In this article, the dentition digital model of the clear aligners can be a dentition digital model obtained during the digital fabrication of clear aligners or other orthodontic treatments, or it can be a dentition digital model obtained by modeling or 3D scanning based on human dentition.

[0020] In this paper, the selected needle thickness gauge measures thickness using two measuring needles, one of which is L-shaped. The needle thickness gauge mentioned is the commonly used needle thickness gauge in the field of orthodontics, and it can perform insertion measurement using an L-shaped measuring needle (which can also be equivalent to a measuring needle with an L-shaped hook tip). Examples include Guanglu's 315-181 model pointed digital caliper, Sanliang JD203 pointer thickness gauge, and Yalen Hercules hook digital thickness gauge.

[0021] In this paper, the digital model of the measuring needle of the needle thickness gauge is obtained by modeling or 3D scanning based on an existing needle thickness gauge. The digital model of the measuring needle includes digital models of two measuring needles, one of which is an L-shaped digital model of the measuring needle. The digital model of the measuring needle formed by the two measuring needles maintains the original spatial position and angle on the needle thickness gauge.

[0022] In this paper, the measurement sites for determining and marking the digital model of the dentition or the digital model of the braces in step (2) are determined based on the fact that the braces and dentition are in a close fit during actual use. Therefore, the measurement sites can be marked on either the digital model of the dentition or the digital model of the braces. Furthermore, since the accuracy of the digital model of the clear dentition is usually lower than that of the digital model of the dentition, it is preferred to mark the sites on the digital model of the dentition. The measurement sites can be the measurement sites conventionally used in this technical field for measuring the thickness of clear dentitions, or they can be custom measurement sites.

[0023] In one preferred technical solution, in order to further improve the standardized measurement of the thickness of the clear aligners and to further contribute to the research on the comfort, durability, and orthodontic effect of clear aligners, the measurement sites in step (2) include the midpoint of the incisal edge of tooth 11, the cusp of tooth 13, the buccal cusp of tooth 14, the mesiobuccal cusp of tooth 16, the mesilingual cusp of tooth 16, the midpoint of the labial / buccal surface of tooth 11, the midpoint of the labial / buccal surface of tooth 16, the midpoint of the lingual / palatal surface of tooth 11, the midpoint of the lingual / palatal surface of tooth 16, the labial / buccal-gingival margin of tooth 11, and the labial / buccal-gingival margin of tooth 16. 11. Tooth lingual / palatal gingival margin point, 16. Tooth lingual / palatal gingival margin point; wherein, the midpoint of the labial / buccal surface and the midpoint of the lingual / palatal surface are the intersections of the mesial-distal midpoint and the occlusal-gingival midpoint of the crown of the tooth, that is, the intersection of the vertical line and the horizontal line that bisects the tooth surface, and are the clinical crown center on teeth with healthy gingiva; the labial / buccal gingival margin point and the lingual / palatal gingival margin point are the most concave points of the gingival margin of the labial / buccal and lingual / palatal surfaces of the crown, respectively. The remaining measurement points are standard terms used in this technical field, and those skilled in the art can know their locations through textbooks in this field.

[0024] In this paper, the measurement direction is determined and marked based on the measurement site obtained in step (2) in step (3). The measurement direction can be the measurement direction commonly used in this technical field for measuring the thickness of transparent braces, or it can be a custom measurement direction.

[0025] In one of the preferred technical solutions, in order to further improve the standardized measurement of the thickness of the clear aligners and to further contribute to the research on the comfort, durability and orthodontic effect of wearing clear aligners, the measurement direction in step (3) includes the incisal direction, the cusp direction and the labial and lingual direction. The incisal direction is based on the measurement point being parallel to the bisector of the angle between the labial and lingual surfaces of the tooth. The cusp direction is based on the measurement point being parallel to the bisector of the angle between the two surfaces that make up the cusp. The labial and lingual direction is based on the measurement point being perpendicular to the labial or lingual surface of the tooth.

[0026] In this paper, step (3) describes placing the digital model of the measuring needle according to the measurement site and measurement direction, so that the digital model of the measuring needle is in a state of measuring the measurement site in the measurement direction. Usually, the central axis of one of the non-L-shaped measuring needles of the digital model of the measuring needle passes through the measurement site and is placed in the same direction as the measurement direction. It should be noted that, apart from the measurement site, the digital model of the measuring needle should not overlap with the digital model of the braces after it is placed.

[0027] In one of the technical solutions, step (3) involves placing a digital model of the measuring needle according to the measurement site and measurement direction. When the L-shaped measuring needle is placed on the side of the dental digital model that fits the tooth (i.e., the L-shaped measuring needle overlaps with the dental digital model in step (5)), the long axis of the L-shaped measuring needle is parallel to or minimizes the angle between the long axis of the corresponding tooth and the tooth.

[0028] In this document, step (5) describes creating a measurement needle navigation channel on the dental arch digital model. The measurement needle navigation channel and the corresponding measurement needle are dynamically coupled to facilitate the measurement needle to extend and be positioned through the measurement needle navigation channel.

[0029] In one technical solution, in order to make the measuring needle extend into the measuring needle navigation channel more smoothly and without deviating from the angle, the optimal diameter size can be determined by repeatedly making measuring needle navigation channel solid models of different diameters based on the accuracy of the digital model when making the physical model (e.g., using 3D printing).

[0030] In one technical solution, when the L-shaped measuring needle in the digital model of the measuring needle overlaps with the digital model of the dental arch, the measuring needle navigation channel is constructed based on the fact that the L-shaped measuring needle can extend in at a constant angle.

[0031] In this paper, step (6) describes the creation of a calibration device based on a digital model of a dental arch with a measuring needle navigation channel. This involves creating a physical model based on the digital model using conventional methods, such as 3D printing.

[0032] In one technical solution, to facilitate use and extend the measurement needle navigation channel, the digital dental arch model is provided with a base in the gingival direction. The base can be constructed based on the actual gingival portion or can be a base with a geometric configuration. The measurement needle navigation channel is extended and passes through the base.

[0033] To better illustrate the present invention and provide a measurement method using the alignment device, the method includes the following steps:

[0034] (I) Assemble and install the alignment device and the clear braces in the same way as the conventional clear braces;

[0035] (II) Insert one of the measuring needles of the needle thickness gauge into the measuring needle navigation channel of the alignment device until it touches the bottom. At this time, the measuring tip of the measuring needle is exactly against the measuring point of the transparent dental brace.

[0036] (III) The thickness of the transparent dental braces was measured using a needle thickness gauge.

[0037] In one technical solution, to facilitate real-time observation of the measurement site and direction when using a calibration device for measurement, the dentition digital model with a measuring needle navigation channel described in step (6) further includes removing the tooth model corresponding to the measuring needle navigation channel from the dentition digital model to form a dentition digital model state similar to "missing teeth". Because the transparent braces are transparent, by removing the teeth, the real-time state of the measuring needle of the needle thickness gauge at the measurement site can be observed more clearly.

[0038] In one technical solution, the completed alignment device can be a 3D printed object generated based on a digital model.

[0039] It should be noted that because clear aligners are designed and manufactured according to the shape of human teeth in the field of orthodontic technology, their specific shape is not consistent. Therefore, for different clear aligners, the measurement points are obviously in different spatial positions. Similarly, the measurement direction is usually related to the angle of each surface of the teeth. Therefore, for different clear aligners, the measurement direction is obviously different.

[0040] The inventive point of this invention is that the selected measurement sites are mainly the central incisors and the first permanent molars, based on their major role in aesthetics and occlusal function, and the areas or sites in which the corresponding braces frequently experience breakage and wear.

[0041] Simultaneously, measuring the thickness of clear aligners requires correct measurement direction for both clinical and research significance. During normal treatment, only the clinical crown is visible in the oral cavity. The direction from the most prominent point of the cervical margin to the midpoint of the incisal edge / cusp is chosen as the coronal plane orientation of the clinical crown. This is then adjusted using a digital 3D tooth model to adjust the sagittal and transverse plane orientations, thus inferring the approximate direction of the tooth's long axis. This direction represents the transmission of occlusal force during normal tooth contact in oral functional movements. When teeth perform functional movements, a correct occlusal force transmission direction reduces the horizontal component of force, protecting the normal structure of periodontal tissues and their adaptive functional changes, while also ensuring stable retention of the clear aligners. A major advantage of clear aligners during orthodontic treatment is their indentation effect on the teeth, specifically the direction of occlusal force transmission and the primary direction of tooth indentation under pressure. Furthermore, frequent occlusal contact also leads to greater wear on the clear aligners at this point. The varying degrees of wear at different points on clear aligners can alter a patient's occlusion and rest-occlusion gaps, affecting not only the treatment or retention of the aligners but also potentially damaging the function of the patient's maxillofacial tissues.

[0042] The location and orientation of study points on fixed clear aligners are crucial for research on clear aligners, both in design and fabrication, as well as in functional movement. Studying the thickness of the clear aligner in this orientation not only makes measurements more accurate and reduces errors, but also allows for occlusal force analysis, which is significant in oral medicine research. Improved occlusal function is an important criterion for evaluating pre- and post-treatment effects and is a commonly used indicator in prosthodontics and orthodontics. Because clear aligners are thin and require high precision, even with fixed points, the measured thickness varies considerably when not fixed in orientation, lacking clinical and research significance. This could even provide incorrect data in studies related to the design and fabrication of clear aligners, resulting in results without medical value.

[0043] The present invention has the following beneficial effects:

[0044] (1) The calibration device provided by the present invention is used to assist in measuring the thickness of different points of transparent braces by fixing the point, orientation and depth, so as to achieve accurate and repeatable measurement.

[0045] (2) The method for preparing the calibration device provided by the present invention is simple and has good promotion benefits. The process conditions adopted are relatively conventional and can be promoted and used in hospitals and clinics of different levels.

[0046] (3) The measurement of the thickness of transparent braces based on the calibration device provided by the present invention can provide useful guidance and assistance for the clinical use of transparent braces and pressure film retainers. Attached Figure Description

[0047] Figure 1 This is a photograph of the calibration device prepared according to Example 1 of the present invention.

[0048] Figure 2 This is a photograph of the calibration device prepared in Example 2 of the present invention.

[0049] Figure 3 The image shows a photograph of a needle-type thickness gauge commonly used in the field of orthodontics, as described in a specific embodiment of the present invention. From left to right, the image shows a Guanglu 315-181 model pointed digital caliper, a Sanliang JD203 pointer-type thickness gauge, and an Aaron Hercules hook-type digital thickness gauge. It is evident from the image that each gauge has two measuring needles, one of which is L-shaped.

[0050] Figure 4 This is an example illustration of some measurement sites in a specific embodiment of the present invention.

[0051] Figure 5 This is an example illustration of some measurement sites in a specific embodiment of the present invention.

[0052] Figure 6 This is an example illustration of some measurement sites in a specific embodiment of the present invention.

[0053] Figure 7 This is an example illustration of a specific embodiment of the present invention where the measurement direction is the incisal edge direction. In the figure, the measurement point is the midpoint of the incisal edge, which is the tip of the measuring needle. The coronal plane, in which the central axis of the measuring needle points, is from the most prominent point of the cervical region of the tooth towards the midpoint of the incisal edge, and the sagittal plane is on the bisector of the angle formed by the labial and lingual surfaces of the tooth.

[0054] Figure 8 This is an example illustration of a specific embodiment of the present invention where the measurement direction is the cusp direction. In the figure, the measurement site is the mesiobuccal cusp, which is the tip of the measuring needle. The coronal plane, in which the central axis of the measuring needle faces, is the bisector of the angle formed by the mesial and distal oblique edges of the cusp, and the sagittal plane is the bisector of the angle formed by the mesiobuccal axial crest and the mesiobuccal triangular crest.

[0055] Figure 9 This is an example illustration of a specific embodiment of the present invention where the measurement direction is labial or lingual. In the figure, the measurement point is the midpoint of the labial surface of the tooth, which is the tip of the measuring needle. The coronal plane in which the central axis of the measuring needle faces is from the most prominent point of the cervical region of the tooth towards the midpoint of the incisal edge / buccal groove (clinical crown long axis). The sagittal plane is the line formed by the two measuring needle tips, which is perpendicular to the tooth surface.

[0056] Figure 10This is another example illustration of the measurement direction in a specific embodiment of the present invention, which is the labial-lingual direction. In the figure, the measurement point is the midpoint of the lingual surface of the tooth, which is the tip of the measuring needle. The coronal plane, in which the central axis of the measuring needle faces, is the highest point of the occlusal plane from the most prominent point of the cervical region of the tooth towards the midpoint of the incisal edge / cusp. The sagittal plane is the line formed by the two measuring needle tips, which is perpendicular to the tooth surface. Detailed Implementation

[0057] To further understand the present invention, preferred embodiments are described below with reference to examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, and not for limiting the scope of the claims. Those skilled in the art can refer to the content of this document to appropriately improve the process parameters. In particular, it should be noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included within the scope of the present invention. The methods and applications of the present invention have been described through preferred embodiments, and those skilled in the art can obviously make modifications or appropriate changes and combinations to the methods and applications described herein without departing from the content, spirit and scope of the present invention to realize and apply the technology of the present invention. Although it is believed that those skilled in the art will fully understand the following terms, the following definitions are set forth to help illustrate the subject matter disclosed in the present invention.

[0058] A method for preparing a standardized calibration device for measuring the thickness of clear aligners includes the following steps:

[0059] (1) Obtain a digital model of the clear braces and a digital model of the dentition corresponding to the clear braces;

[0060] Obtain the digital model of the measuring needle of the needle thickness gauge. The selected needle thickness gauge measures thickness using two measuring needles, one of which is L-shaped.

[0061] (2) Identify and label the measurement sites in the digital model of the dentition or the digital model of the braces;

[0062] (3) Determine and mark the measurement direction based on the measurement sites obtained in step (2);

[0063] (4) Based on the measurement site and measurement direction, place the digital model of the measuring needle so that the digital model of the measuring needle presents a state in which the measurement site is measured in the measurement direction;

[0064] (5) Assemble the digital model of the braces and the digital model of the dental arch according to the conventional installation method of transparent braces, and create a measurement needle navigation channel on the digital model of the dental arch based on the overlapping part of the model of the digital model of the dental arch and the digital model of the measuring needle.

[0065] (6) Based on the digital model of the dental arch with a measuring needle navigation channel, the alignment device is made.

[0066] In this article, the digital model of the clear aligners can be obtained through the digital fabrication process of the clear aligners, or it can be obtained by modeling or 3D scanning based on an existing clear aligner.

[0067] In this article, the dentition digital model of the clear aligners can be a dentition digital model obtained during the digital fabrication of clear aligners or other orthodontic treatments, or it can be a dentition digital model obtained by modeling or 3D scanning based on human dentition.

[0068] In this paper, the selected needle thickness gauge measures thickness using two measuring needles, one of which is L-shaped. This needle thickness gauge is a commonly used type in orthodontics and allows for insertion-type measurement using the L-shaped measuring needle (which can also be equivalent to a measuring needle with an L-shaped hook tip). In one implementation, examples include the Guanglu 315-181 model pointed digital caliper, the Sanliang JD203 pointer thickness gauge, and the Aaron Hercules hook-type digital thickness gauge, etc., as shown in the appendix. Figure 3 As shown.

[0069] In this paper, the digital model of the measuring needle of the needle thickness gauge is obtained by modeling or 3D scanning based on an existing needle thickness gauge. The digital model of the measuring needle includes digital models of two measuring needles, one of which is an L-shaped digital model of the measuring needle. The digital model of the measuring needle formed by the two measuring needles maintains the original spatial position and angle on the needle thickness gauge.

[0070] In this paper, the measurement sites for determining and marking the digital model of the dentition or the digital model of the braces in step (2) are determined based on the fact that the braces and dentition are in a close fit during actual use. Therefore, the measurement sites can be marked on either the digital model of the dentition or the digital model of the braces. Furthermore, since the accuracy of the digital model of the clear dentition is usually lower than that of the digital model of the dentition, it is preferred to mark the sites on the digital model of the dentition. The measurement sites can be the measurement sites conventionally used in this technical field for measuring the thickness of clear dentitions, or they can be custom measurement sites.

[0071] In one preferred embodiment, to further improve the standardized measurement of the thickness of the clear aligners and to further contribute to the research on the comfort, durability, and orthodontic effect of clear aligners, the measurement sites in step (2) include the midpoint of the incisal edge of tooth 11, the cusp of tooth 13, the buccal cusp of tooth 14, the mesiobuccal cusp of tooth 16, the mesilingual cusp of tooth 16, the midpoint of the labial / buccal surface of tooth 11, the midpoint of the labial / buccal surface of tooth 16, the midpoint of the lingual / palatal surface of tooth 11, the midpoint of the lingual / palatal surface of tooth 16, the labial / buccal-gingival margin of tooth 11, and the labial / buccal-gingival margin of tooth 16. 11. Tooth lingual / palatal gingival margin point; 16. Tooth lingual / palatal gingival margin point; wherein, the midpoint of the labial / buccal surface and the midpoint of the lingual / palatal surface are the intersections of the mesial-distal midpoint and the occlusal-gingival midpoint of the crown on the labial / buccal and lingual / palatal surfaces, respectively, that is, the intersection of the vertical line and the horizontal line bisecting the tooth surface, which is the clinical crown center on teeth with healthy gingiva; the labial / buccal gingival margin point and the lingual / palatal gingival margin point are the most concave points of the gingival margin on the labial / buccal and lingual / palatal surfaces of the crown, respectively. The remaining measurement sites are standard terms used in this technical field, and those skilled in the art can learn their locations from textbooks in this field. The above measurement sites can be combined with the appendix. Figures 4-6 To aid understanding.

[0072] In this paper, the measurement direction is determined and marked based on the measurement site obtained in step (2) in step (3). The measurement direction can be the measurement direction commonly used in this technical field for measuring the thickness of transparent braces, or it can be a custom measurement direction.

[0073] In one preferred embodiment, to further improve the standardized measurement of the thickness of clear aligners and to further contribute to the research on the comfort, durability, and orthodontic effect of clear aligners, the measurement directions in step (3) include the incisal direction, the cusp direction, and the labiolingual direction. The incisal direction is based on the measurement point being parallel to the bisector of the angle between the labiolingual and cusp surfaces. The cusp direction is based on the measurement point being parallel to the bisector of the angle between the two surfaces constituting the cusp. The labiolingual direction is based on the measurement point being perpendicular to the labial or lingual surface. The above measurement directions can be combined with the attached... Figures 7-10 To aid understanding.

[0074] In this paper, step (3) describes placing the digital model of the measuring needle according to the measurement site and measurement direction, so that the digital model of the measuring needle is in a state of measuring the measurement site in the measurement direction. Usually, the central axis of one of the non-L-shaped measuring needles of the digital model of the measuring needle passes through the measurement site and is placed in the same direction as the measurement direction. It should be noted that, apart from the measurement site, the digital model of the measuring needle should not overlap with the digital model of the braces after it is placed.

[0075] In one embodiment, step (3) involves placing a digital model of the measuring needle according to the measurement site and measurement direction. When the L-shaped measuring needle is placed on the side of the dental digital model that fits the tooth (i.e., the L-shaped measuring needle overlaps with the dental digital model in step (5)), the long axis of the L-shaped measuring needle is parallel to or minimizes the angle between the long axis of the corresponding tooth and the tooth.

[0076] In this document, step (5) describes creating a measurement needle navigation channel on the dental arch digital model. The measurement needle navigation channel and the corresponding measurement needle are dynamically coupled to facilitate the measurement needle to extend and be positioned through the measurement needle navigation channel.

[0077] In one embodiment, in order to make the measuring needle extend into the measuring needle navigation channel more smoothly and without deviating from the angle, the optimal diameter size can be determined by repeatedly making measuring needle navigation channel solid models of different diameters based on the accuracy of the digital model when making the physical model (e.g., using 3D printing).

[0078] In one embodiment, when the L-shaped measuring needle in the digital model of the measuring needle overlaps with the digital model of the dental arch, the measuring needle navigation channel is constructed based on the fact that the L-shaped measuring needle can be inserted at a constant angle. For example, the measuring needle navigation channel is constructed by maintaining a translational insertion method, which is equivalent to a "wider measuring needle" being inserted.

[0079] In this paper, step (6) describes the creation of a calibration device based on a digital model of a dental arch with a measuring needle navigation channel. This involves creating a physical model based on the digital model using conventional methods, such as 3D printing.

[0080] In one embodiment, to facilitate use and extend the measurement needle navigation channel, the digital dental arch model is provided with a base in the gingival direction. The base may be constructed based on the actual gingival portion or may be a base with a specific geometric configuration. The measurement needle navigation channel is extended and passes through the base.

[0081] To better illustrate the present invention and provide a measurement method using the alignment device, the method includes the following steps:

[0082] (I) Assemble and install the alignment device and the clear braces in the same way as the conventional clear braces;

[0083] (II) Insert one of the measuring needles of the needle thickness gauge into the measuring needle navigation channel of the alignment device until it touches the bottom. At this time, the measuring tip of the measuring needle is exactly against the measuring point of the transparent dental brace.

[0084] (III) The thickness of the transparent dental braces was measured using a needle thickness gauge.

[0085] In one embodiment, to facilitate real-time observation of the measurement site and direction during measurement using the alignment device, the dentition digital model with the measuring needle navigation channel described in step (6) further includes removing the tooth model corresponding to the measuring needle navigation channel from the dentition digital model, forming a dentition digital model state similar to "missing teeth". Because the transparent braces are transparent, by removing the teeth, the real-time state of the measuring needle of the needle thickness gauge at the measurement site can be observed more clearly.

[0086] In one embodiment, the completed alignment device can be a 3D printed object generated based on a digital model.

[0087] It should be noted that because clear aligners are designed and manufactured according to the shape of human teeth in the field of orthodontic technology, their specific shape is not consistent. Therefore, for different clear aligners, the measurement points are obviously in different spatial positions. Similarly, the measurement direction is usually related to the angle of each surface of the teeth. Therefore, for different clear aligners, the measurement direction is obviously different.

[0088] The inventive point of this invention is that the selected measurement sites are mainly the central incisors and the first permanent molars, based on their major role in aesthetics and occlusal function, and the areas or sites in which the corresponding braces frequently experience breakage and wear.

[0089] Simultaneously, measuring the thickness of clear aligners requires correct measurement direction for both clinical and research significance. During normal treatment, only the clinical crown is visible in the oral cavity. The direction from the most prominent point of the cervical margin to the midpoint of the incisal edge / cusp is chosen as the coronal plane orientation of the clinical crown. This is then adjusted using a digital 3D tooth model to adjust the sagittal and transverse plane orientations, thus inferring the approximate direction of the tooth's long axis. This direction represents the transmission of occlusal force during normal tooth contact in oral functional movements. When teeth perform functional movements, a correct occlusal force transmission direction reduces the horizontal component of force, protecting the normal structure of periodontal tissues and their adaptive functional changes, while also ensuring stable retention of the clear aligners. A major advantage of clear aligners during orthodontic treatment is their indentation effect on the teeth, specifically the direction of occlusal force transmission and the primary direction of tooth indentation under pressure. Furthermore, frequent occlusal contact also leads to greater wear on the clear aligners at this point. The varying degrees of wear at different points on clear aligners can alter a patient's occlusion and rest-occlusion gaps, affecting not only the treatment or retention of the aligners but also potentially damaging the function of the patient's maxillofacial tissues.

[0090] The location and orientation of study points on fixed clear aligners are crucial for research on clear aligners, both in design and fabrication, as well as in functional movement. Studying the thickness of the clear aligner in this orientation not only makes measurements more accurate and reduces errors, but also allows for occlusal force analysis, which is significant in oral medicine research. Improved occlusal function is an important criterion for evaluating pre- and post-treatment effects and is a commonly used indicator in prosthodontics and orthodontics. Because clear aligners are thin and require high precision, even with fixed points, the measured thickness varies considerably when not fixed in orientation, lacking clinical and research significance. This could even provide incorrect data in studies related to the design and fabrication of clear aligners, resulting in results without medical value.

[0091] The present application will be further explained in detail below with reference to embodiments. However, those skilled in the art should understand that these embodiments are provided for illustrative purposes only and are not intended to limit the present application.

[0092] Example 1

[0093] This embodiment describes a method for preparing a standardized calibration device for measuring the thickness of clear aligners, comprising the following steps:

[0094] (1) Obtain a digital model of the clear braces and a digital model of the dentition corresponding to the clear braces;

[0095] Obtain the digital model of the measuring needle of the needle thickness gauge. The selected needle thickness gauge measures thickness using two measuring needles, one of which is L-shaped.

[0096] (2) Determine and mark the measurement sites of the digital dental model: midpoint of the incisal edge of tooth 11, cusp of tooth 13, buccal cusp of tooth 14, mesobuccal cusp of tooth 16, and mesoblingual cusp of tooth 16;

[0097] (3) Determine and mark the measurement direction based on the measurement sites obtained in step (2):

[0098] The measurement point 11 is the midpoint of the incisal edge of the tooth. The coronal plane is the direction from the most prominent point of the cervical region of the tooth toward the midpoint of the incisal edge of the tooth, and the sagittal plane is the direction of the angle bisector of the angle formed by the labial and lingual surfaces of the tooth.

[0099] The measurement site for tooth cusp 13 is as follows: the coronal plane is the direction from the most prominent point of the cervical region of the tooth toward the cusp of the tooth, and the sagittal plane is the direction of the angle bisector of the angle formed by the labial and lingual surfaces of the tooth;

[0100] The measurement site for the buccal cusp of tooth 14 is as follows: the coronal plane is the direction from the most prominent point of the cervical region of the tooth toward the buccal cusp of that tooth, and the sagittal plane is the direction of the angle bisector of the angle formed by the buccal axial crest and the buccal cusp triangular crest.

[0101] The measurement site for the mesiobuccal cusp of tooth 16 is as follows: the coronal plane is the direction of the angle bisector of the angle formed by the mesial and distal oblique edges of the cusp, and the sagittal plane is the direction of the angle bisector of the angle formed by the mesiobuccal axial crest and the mesiobuccal cusp triangular crest.

[0102] The measurement site for the mesial lingual cusp of tooth 16 is as follows: the coronal plane is the direction of the angle bisector of the angle formed by the mesial and distal oblique edges of the cusp, and the sagittal plane is the direction of the angle bisector of the angle formed by the mesial lingual ridge and the mesial lingual cusp triangular ridge.

[0103] (4) Based on the measurement site and measurement direction, place the digital model of the measuring needle so that the digital model of the measuring needle presents a state in which the measurement site is measured in the measurement direction;

[0104] (5) Assemble the digital model of the braces and the digital model of the dental arch according to the conventional installation method of transparent braces, and create a measurement needle navigation channel on the digital model of the dental arch based on the overlapping part of the model of the digital model of the dental arch and the digital model of the measuring needle.

[0105] (6) A base is provided in the gingival direction according to the digital model of the dentition with a measuring needle navigation channel. The base is a base with a geometric configuration, and the measuring needle navigation channel extends and passes through the base.

[0106] On the digital dental arch model, the tooth model corresponding to the measurement needle navigation channel is removed to form a digital dental arch model state similar to "missing teeth";

[0107] The alignment device was finally fabricated using 3D printing, such as... Figure 1 As shown.

[0108] Example 2

[0109] This embodiment describes a method for preparing a standardized calibration device for measuring the thickness of clear aligners, comprising the following steps:

[0110] (1) Obtain a digital model of the clear braces and a digital model of a portion of the dentition corresponding to the clear braces;

[0111] Obtain the digital model of the measuring needle of the needle thickness gauge. The selected needle thickness gauge measures thickness using two measuring needles, one of which is L-shaped.

[0112] (2) Determine and mark the measurement points of the digital model of the braces: midpoint of the labial surface of tooth 11, midpoint of the buccal surface of tooth 16, midpoint of the lingual surface of tooth 11, midpoint of the palatal surface of tooth 16, labial gingival margin of tooth 11, buccal gingival margin of tooth 16, lingual gingival margin of tooth 11, and palatal gingival margin of tooth 16.

[0113] (3) Determine and mark the measurement direction based on the measurement sites obtained in step (2):

[0114] The measurement point 11 is the midpoint of the labial surface of the tooth: the coronal plane is the direction from the most prominent point of the cervical region of the tooth toward the midpoint of the incisal edge, and the sagittal plane is the line formed by the tips of the two measuring needles perpendicular to the labial surface;

[0115] The midpoint of the buccal surface of tooth 16 is the measurement site: the coronal plane is the direction from the most prominent point of the cervical region of the tooth toward the buccal groove (clinical long axis of the crown), and the sagittal plane is the line formed by the tips of the two measuring needles perpendicular to the buccal surface;

[0116] The midpoint of the lingual surface of the tooth at measurement point 11 is: the coronal plane is the direction from the most prominent point of the cervical region toward the midpoint of the incisal edge, and the sagittal plane is the direction perpendicular to the tooth surface by the line formed by the tips of the two measuring needles.

[0117] The midpoint of the palatal surface of tooth 16 is measured at the following locations: the coronal plane is the direction from the most prominent point of the cervical region of the tooth toward the lingual groove (clinical crown long axis), and the sagittal plane is the line formed by the tips of the two measuring needles perpendicular to the tooth surface.

[0118] The measurement site 11, the labial-gingival margin point, is as follows: in the coronal plane, it is the direction from the most prominent point of the cervical region of the tooth toward the midpoint of the incisal margin; in the sagittal plane, it is the line formed by the tips of the two measuring needles that is perpendicular to the labial surface.

[0119] The measurement site for tooth 16, the buccal gingival margin, is as follows: in the coronal plane, it is the direction from the most prominent point of the cervical region of the tooth toward the buccal groove (clinical long axis of the crown); in the sagittal plane, it is the line formed by the tips of the two measuring needles perpendicular to the buccal surface.

[0120] Measurement point 11, the lingual gingival margin point, is: in the coronal plane, it is the direction from the most prominent point of the cervical region of the tooth toward the midpoint of the incisal margin; in the sagittal plane, it is the line formed by the tips of the two measuring needles perpendicular to the tooth surface.

[0121] The measurement point for tooth 16 is the palatogingival margin: the coronal plane is the direction from the most prominent point of the tooth neck towards the lingual groove (clinical crown long axis), and the sagittal plane is the line formed by the tips of the two measuring needles perpendicular to the tooth surface;

[0122] (4) Based on the measurement site and measurement direction, place the digital model of the measuring needle so that the digital model of the measuring needle presents a state in which the measurement site is measured in the measurement direction;

[0123] (5) The digital model of the dental braces and the digital model of part of the dental arch are assembled and installed in the same way as the conventional transparent dental braces. Based on the overlapping part of the digital model of the dental arch and the digital model of the measuring needle, a measuring needle navigation channel is created on the digital model of the dental arch.

[0124] (6) A base is provided in the gingival direction according to the digital model of the dentition with a measuring needle navigation channel. The base is a base with a geometric configuration, and the measuring needle navigation channel extends and passes through the base.

[0125] On the digital dental arch model, the tooth model corresponding to the measurement needle navigation channel is removed to form a digital dental arch model state similar to "missing teeth";

[0126] The alignment device was finally fabricated using 3D printing, such as... Figure 2 As shown.

[0127] The embodiments of this application will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be construed as limiting the scope of this application. Where specific conditions are not specified in the examples, conventional conditions or conditions recommended by the manufacturer shall apply. Where the manufacturers of reagents or instruments are not specified, they are all commercially available conventional products. This application should not be construed as being limited to the specific embodiments described.

Claims

1. A method for preparing a standardized calibration device for measuring the thickness of clear aligners, characterized in that... Includes the following steps: (1) Obtain a digital model of the clear braces and a digital model of the dentition corresponding to the clear braces; Obtain the digital model of the measuring needle of the needle thickness gauge. The selected needle thickness gauge measures thickness using two measuring needles, one of which is L-shaped. (2) Identify and label the measurement sites of the digital model of the dental arch or the digital model of the braces; (3) Determine and mark the measurement direction based on the measurement sites obtained in step (2); (4) Based on the measurement site and measurement direction, place the digital model of the measuring needle so that the digital model of the measuring needle is in a state of measuring the measurement site in the measurement direction; (5) Assemble the digital model of the dental braces and the digital model of the dental arch according to the conventional installation method of transparent dental braces, and create a measurement needle navigation channel on the digital model of the dental arch based on the overlapping part of the model of the digital model of the dental arch and the digital model of the measurement needle; (6) Based on the digital model of the dental arch with a measuring needle navigation channel, the alignment device is made.

2. The preparation method according to claim 1, characterized in that: The measurement sites in step (2) include the midpoint of the incisal edge of tooth 11, the cusp of tooth 13, the buccal cusp of tooth 14, the mesiobuccal cusp of tooth 16, the mesilingual cusp of tooth 16, the midpoint of the labial / buccal surface of tooth 11, the midpoint of the labial / buccal surface of tooth 16, the midpoint of the lingual / palatal surface of tooth 11, the midpoint of the lingual / palatal surface of tooth 16, the labial / buccal-gingival margin of tooth 11, the labial / buccal-gingival margin of tooth 16, the lingual / palatal-gingival margin of tooth 11, and the lingual / palatal-gingival margin of tooth 16. Among them, the midpoint of the labial / buccal surface and the midpoint of the lingual / palatal surface are the intersections of the mesial-distal midpoint and the occlusal-gingival midpoint of the crown of the tooth, that is, the intersection of the vertical line and the horizontal line that bisect the tooth surface, which is the clinical crown center on a tooth with healthy gingiva; the labial / buccal gingival margin point and the lingual / palatal gingival margin point are the most concave points of the gingival margin of the labial / buccal and lingual / palatal surfaces of the crown.

3. The preparation method according to claim 1, characterized in that: In step (3), the measurement directions include the incisal direction, the cusp direction, and the labial / lingual direction. The incisal direction is based on the measurement point being parallel to the bisector of the angle between the labial / lingual surfaces of the tooth. The cusp direction is based on the measurement point being parallel to the bisector of the angle between the two surfaces that make up the cusp. The labial / lingual direction is based on the measurement point being perpendicular to the labial or lingual surface of the tooth.

4. The preparation method according to claim 1, characterized in that: In step (3), the digital model of the measuring needle is placed according to the measurement site and measurement direction. When the L-shaped measuring needle is placed on the side of the dental aligner digital model that fits the tooth, the long axis of the L-shaped measuring needle is parallel to the long axis of the corresponding tooth or the angle between them is minimized.

5. The preparation method according to claim 1, characterized in that: When the L-shaped measuring needle in the digital model of the measuring needle overlaps with the digital model of the dental arch, the measuring needle navigation channel is constructed based on the fact that the L-shaped measuring needle can extend in at a constant angle.

6. The preparation method according to claim 1, characterized in that: The digital dental arch model has a base in the gingival direction. The base can be constructed based on the actual gingival portion or it can be a base with a geometric configuration. The measuring needle navigation channel extends and passes through the base.

7. The preparation method according to claim 1, characterized in that: The dentition digital model with measuring needle navigation channel described in step (6) also includes removing the tooth model corresponding to the measuring needle navigation channel from the dentition digital model.

8. A leveling device, characterized in that... It is prepared by the preparation method of the standardization device for measuring the thickness of transparent dental braces as described in claim 1.

9. The alignment device according to claim 8, characterized in that... The measurement method includes the following steps: (I) Assemble and install the alignment device and the clear braces in the same way as the conventional clear braces; (II) Insert one of the measuring needles of the needle thickness gauge into the measuring needle navigation channel of the alignment device until it touches the bottom. At this time, the measuring tip of the measuring needle is exactly against the measuring point of the transparent dental brace. (III) The thickness of the transparent dental braces was measured using a needle thickness gauge.

10. The application of the alignment device of claim 8 in the measurement of the thickness of clear dental braces.

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