阅读说明：本技术 用于正畸对准器的设计和改善其保持的系统和方法 (System and method for design of orthodontic aligner and improved retention thereof ) 是由 J·马 于 2018-06-15 设计创作，主要内容包括：公开了用于设计热成型的可移除正畸对准器并改善这种对准器对患者牙齿的保持的系统和方法。该系统通常包括构造成获取患者的牙列的数字图像的数字扫描仪；和计算环境，其构造成：接收该数字图像的副本；相对于数字图像中特征化的一个或多个牙齿创建参考平面；定位一条线，其从参考平面垂直地延伸并且与一个或多个牙齿中的每个牙齿的最大凸度的高度的相切地延伸；测量在该垂直线与一个或多个牙齿中的每个牙齿的外表面之间的倒凹的区域；沿着一个或多个牙齿中的每个牙齿的周边在多个点处重复上述步骤；以及，构建用于一个或多个牙齿中的每个牙齿的倒凹区域的三维模型。(Systems and methods for designing thermoformed removable orthodontic aligners and improving the retention of such aligners to a patient's teeth are disclosed. The system generally includes a digital scanner configured to acquire a digital image of a patient's dentition; and a computing environment configured to: receiving a copy of the digital image; creating a reference plane relative to one or more teeth characterized in the digital image; positioning a line extending perpendicularly from the reference plane and tangentially to a height of maximum convexity of each of the one or more teeth; measuring an area of undercut between the vertical line and an outer surface of each of the one or more teeth; repeating the above steps at a plurality of points along the periphery of each of the one or more teeth; and constructing a three-dimensional model of the undercut region for each of the one or more teeth.)

1. A system for designing a removable orthodontic aligner, the system comprising a digital scanner configured to obtain digital images of a patient's dentition and a computing environment comprising a central processor, memory, imaging software and a graphical user interface, wherein the system is configured to:

(a) receiving a copy of the digital image;

(b) creating a reference plane relative to one or more teeth characterized in the digital image;

(c) positioning a line extending perpendicularly from the reference plane and extending tangentially to a height of maximum convexity of each of the one or more teeth;

(d) measuring an area of undercut of an area contained between the vertical line and an outer surface of each of the one or more teeth;

(e) repeating steps (a) - (d) at a plurality of points along the periphery of each of the one or more teeth; and

(f) a three-dimensional model is constructed that represents a compilation of each undercut region calculated by the system for each of the one or more teeth.

2. The system of claim 1, further configured to transform the three-dimensional model into a set of dimensions related to a preferred internal dimension of a removable orthodontic aligner.

3. The system of claim 2, wherein the preferred internal dimensions of the removable orthodontic aligner are configured to mate with and retainingly seat adjacent to an inverted concave region for each of the one or more teeth.

4. The system of claim 3, further configured to identify a desired location, size, and configuration of an attachment device to be attached to the one or more teeth, wherein the attachment device is configured to enhance retention of the removable orthodontic aligner to the one or more teeth.

5. The system of claim 3, further configured to design and incorporate the preferred internal dimensions of the removable orthodontic aligner and one or more anti-reduction features into a production model of the removable orthodontic aligner, wherein the production model is configured to be used to manufacture the removable orthodontic aligner.

6. The system of claim 5, wherein the anti-repositioning feature is configured to resist or prevent repositioning movement of the underlying tooth.

7. The system of claim 6, wherein the anti-repositioning features comprise one or more protuberances, dots, dimples, indentations, depressions, ridges, or combinations thereof, in a configuration and positioned within the aligner to resist or prevent repositioning movement of the underlying tooth.

8. A method for designing a removable orthodontic aligner, the method comprising operating a digital scanner to obtain digital images of dentitions of a patient and operating a computing environment comprising a central processor, memory, imaging software, and a graphical user interface to:

(a) receiving a copy of the digital image;

(b) creating a reference plane relative to one or more teeth characterized in the digital image;

(c) positioning a line extending perpendicularly from the reference plane and extending tangentially to a height of maximum convexity of each of the one or more teeth;

(d) measuring an area of undercut between the vertical line and an outer surface of each of the one or more teeth;

(e) repeating steps (a) - (d) at a plurality of points along the periphery of each of the one or more teeth; and

(f) a three-dimensional model representing a compilation of each undercut region calculated by the system for each of the one or more teeth is constructed.

9. The method of claim 8, further comprising converting the three-dimensional model to a set of dimensions related to a preferred internal dimension of a removable orthodontic aligner.

10. The method of claim 9, wherein the preferred internal dimensions of the removable orthodontic aligner are configured to mate and retainingly seat the removable orthodontic aligner with the inverted concave region for each of the one or more teeth.

11. The method of claim 10, further comprising applying a dental restoration to one or more of the patient's teeth, wherein the dental restoration exhibits a desired and predetermined undercut.

12. The method of claim 11, wherein the prosthesis is a dental crown.

13. The method of claim 10, further comprising determining a desired location, size, and configuration of an attachment device to be attached to the one or more teeth, wherein the attachment device is configured to enhance retention of the removable orthodontic aligner to the one or more teeth.

14. A removable orthodontic aligner configured to mate with and remain contiguously disposed with a reverse-concave region of each of one or more teeth of a patient, wherein the removable orthodontic aligner is produced by the steps of:

(a) operating a digital scanner to obtain a digital image of a patient's dentition;

(b) operating a computing environment comprising a central processor, memory, imaging software, and a graphical user interface to:

(i) receiving a copy of the digital image;

(ii) creating a reference plane relative to one or more teeth characterized in the digital image;

(iii) positioning a line extending perpendicularly from the reference plane and extending tangentially to a height of maximum convexity of each of the one or more teeth;

(iv) measuring an area of undercut between the vertical line and an outer surface of each of the one or more teeth;

(v) (iii) repeating steps (i) - (iv) at a plurality of points along the periphery of each of the one or more teeth; and

(vi) constructing a three-dimensional model representing a compilation of each region of undercut calculated by the system for each of the one or more teeth; and

(c) producing a removable orthodontic aligner exhibiting an internal dimension configured to mate with and remain contiguously disposed with a reverse-recessed area for each of one or more teeth.

15. The removable orthodontic aligner of claim 14, further comprising an attachment device configured to (a) be attached to the one or more teeth and (b) enhance retention of the removable orthodontic aligner to the one or more teeth.

16. The removable orthodontic aligner of claim 15, wherein the size and configuration of the attachment device is optimized by the system.

17. The removable orthodontic aligner of claim 14, wherein the attachment device is configured to attach to the one or more teeth at a location optimized by the system.

18. The removable orthodontic aligner of claim 14, further comprising one or more anti-reduction features, wherein the anti-reduction features are configured to resist or prevent reduction movement of an underlying tooth.

19. The removable orthodontic aligner of claim 18, wherein the anti-reduction features comprise one or more bumps, dots, dimples, dents, depressions, ridges, or a combination of the foregoing in a configuration and positioned within the aligner to resist or prevent reduction movement of an underlying tooth.

Technical Field

Background

Removable orthodontic aligners are increasingly being used to impart orthodontic tooth movement (in connection with orthodontic treatment regimens). Such orthodontic aligners are generally superior to more conventional orthodontic appliances for various reasons, i.e., removable orthodontic aligners have been found to be visually more desirable, comfortable, and easier to use (as compared to conventional orthodontic appliances such as metal brackets). While removable orthodontic aligners have been shown to be effective in imparting desired tooth motion, challenges remain associated with maintaining such aligners on a patient's teeth. It has been shown that the retention of orthodontic aligners can be adversely affected by a variety of factors. In particular, it has been shown that variations in tooth morphology within the patient are often the cause of aligner retention deficiencies.

Accordingly, there is a continuing need for systems and methods for designing and manufacturing orthodontic aligners in a manner that meets patient-specific variations in tooth morphology and position. In addition, there is a continuing need for systems and methods for designing and positioning custom attachment devices (adapters) for teeth when such attachment devices are needed or desired to facilitate enhanced retention of a dental aligner to a patient's teeth. Such custom formed attachment devices may further promote desired tooth movement (i.e., improve the efficacy of the orthodontic treatment plan).

As will be demonstrated below, the invention described herein addresses this continuing need (as well as other needs).

Disclosure of Invention

In accordance with certain aspects of the present invention, systems for designing thermoformed removable orthodontic aligners and improving the retention of such aligners to a patient's teeth are disclosed. In certain embodiments, the system includes a digital scanner configured to obtain a digital image of a patient's dentition and a computing environment (with a graphical user interface) configured to receive (and analyze) a copy of the digital image. More specifically, within the computing environment and its associated graphical user interface, the system is further configured to create a reference plane relative to the one or more teeth characterized within the digital image (and locate a line extending perpendicularly from the reference plane that also extends tangentially to the height of the maximum convexity of each of the one or more teeth being analyzed by the system). Additionally, within the computing environment (and graphical user interface), the system is configured to subsequently measure the area of undercut between such a vertical line and the outer surface of each of the one or more teeth being analyzed. The system is preferably configured to repeat the above steps at a plurality of points along the periphery of each of the one or more teeth-and then construct a three-dimensional model of the inverted concave region for each of the analyzed one or more teeth. The three-dimensional model of the inverted concave region can then be used to design an interior region of the removable orthodontic aligner such that the interior dimension of the removable orthodontic aligner is configured to match and remain contiguously disposed with the inverted concave region for each of the one or more teeth.

According to another aspect of the invention, the invention includes methods of using the systems described herein (for designing thermoformed removable orthodontic aligners and improving the retention of such aligners to a patient's teeth) and removable orthodontic aligners designed and produced using the systems and methods described herein.

According to further aspects of the present invention, systems and methods are provided for designing and producing temporary or permanent dental restorations (e.g., crowns) that are customized to provide a desired restoration undercut for enhanced aligner retention and treatment.

According to still other embodiments of the present invention, systems and methods are provided for designing and producing aligners and prostheses customized to exhibit integrated anti-reduction features, such as dimples, ridges, depressions, and others.

The above and additional features of the invention are further illustrated in the detailed description contained herein.

Drawings

Fig. 1 is a graph showing changes in tooth morphology that are common in various types of teeth (e.g., incisors, canines, premolars, and molars).

Fig. 2 is a graph showing tooth morphology changes common in a single type of tooth, such as changes that are common between central incisors.

Fig. 3 is a diagram showing the application of temporary (carbon) marks or lines around the height (or first contact point) of the contour of a tooth using a dental gauge.

FIG. 4 is a diagram showing the system of the present invention used to (1) create a reference plane; (2) positioning a line perpendicular to the reference plane, the line also contacting the height of (or extending tangential to) the maximum convexity of the tooth; and (3) measuring the area of undercut between the vertical line and the tooth surface.

FIG. 5 is a flow chart summarizing certain methods of the present invention.

Fig. 6 is a diagram showing attachment devices (adapters) attached to teeth that may be used to further facilitate retention between the orthodontic aligner and the underlying teeth.

Fig. 7 is a diagram illustrating a crown preparation with minimal undercut.

Fig. 8 is a diagram showing another crown specifically designed with enough undercut (compared to the undercut of fig. 7) to enhance the retention of the aligner to the tooth.

FIG. 9 is a view showing a misaligned tooth (rotational misalignment); the malpositioned tooth in a counter-rotated/straightened position; the direction of the rotational reset force; and a map of the position of the anti-reset elevated ridges.

FIG. 10 is a view showing another malpositioned tooth (retrocline) malposition; the malpositioned tooth in an orthodontic position; the direction of the restorative force exerted on the corrected teeth; and a map of the position of the elevated ridges against repositioning.

FIG. 11 is a view showing yet another misaligned tooth (an invasive tooth); the malpositioned tooth in an orthodontic position; a direction of a restoring force exerted on the orthodontic teeth; and a map of the location of the anti-reduction (anti-crushing) features/ridges on the crown and aligner.

Detailed Description

Several preferred embodiments of the present invention will be described in detail below. These examples are provided by way of illustration only and should not unduly limit the scope of the present invention. Indeed, those skilled in the art will appreciate that many modifications and variations of the present invention are taught which can be made, used and made without departing from the scope and spirit of the invention as described herein.

Referring now to fig. 1 and 2, it is well known that a patient's teeth exhibit significantly different morphologies (i.e., when comparing the morphology of one tooth to another). For example, as shown in FIG. 1, morphological differences exist between the crown regions 10 of the teeth. In addition, as shown in FIG. 2, significant variations also exist in a single type of tooth, such as the variations that often exist between central incisors 12. Such changes in tooth morphology often compromise the holding ability of the orthodontic aligner. Accordingly, as noted above, it is an object of the present invention to provide a system and method that can be used to quantify this change in tooth morphology (and undercuts associated with each tooth within a set of teeth), allowing the internal dimensions of an orthodontic aligner to be designed and manufactured to more accurately accommodate differences in this morphology between a patient's teeth (which enhances the fit, retention, and efficacy of the orthodontic aligner).

Referring now to fig. 3, such differences in tooth morphology have traditionally been measured using a so-called dental gauge 14. More specifically, dental gauges 14 have been used to mark, identify and determine the amount of undercut of an individual tooth. Notably, conventional dental gauges 14 have been used in this capacity to assist in the design of partial dentures, but have not been used in the design of orthodontic appliances (e.g., removable orthodontic aligners). Referring to fig. 3, for example, such a dental gauge 14 (e.g., Jelenko carbon marker) may be used to mark (with a temporary carbon line 16) one or more teeth and then measure the height of the contour (or first contact point) between the different teeth. As shown in fig. 3, the dental gauge 14 may be used by moving the dental gauge 14 around the perimeter of the tooth in a single plane such that the dental gauge 14 is configured to apply a temporary (carbon) mark or line 16 around the height (or first contact point) of the contour. Such marking methods have been used later by clinicians to identify the amount of undercut (tooth morphology) of a particular tooth (furthermore, they have traditionally been used in the design of partial dentures).

The system and method of the present invention preferably employs the use of certain digital techniques to more accurately and efficiently identify and measure the amount of undercut (tooth morphology) for one or more teeth (rather than using a more basic dental measurer 14). More specifically, the present invention utilizes a computer/digital system to quantify the undercut and hold profile of one or more teeth. Referring now to FIG. 4, the system of the present invention is configured to create and utilize at least one reference plane 18. The present invention provides that such a reference plane 18 may for example represent a horizontal reference plane 18. However, the reference plane 18 need not necessarily exhibit a horizontal orientation (vertical or other orientations may also be employed).

The present invention provides that the system is configured to then position at least one line 20 extending perpendicularly from the reference plane 18, while the perpendicular line 20 is simultaneously positioned to contact (and extend tangentially to) each tooth at (and extending tangentially to) the most prominent position 22 of the tooth (the most prominent position of the tooth is also referred to as the "height of maximum convexity"). The system then uses the vertical line 20 to identify and quantify the area 24 that exists between the vertical line 20 and the variable/outer tooth surface. The present invention provides that a user of the system visualizes the reference plane 18 and the at least one line 20 extending perpendicularly from the reference plane 18 in a graphical user interface of the system.

Importantly, in certain embodiments, the system of the present invention is preferably configured to perform such procedures and analysis around the entire perimeter 26 of a particular tooth (e.g., at multiple points around the perimeter 26 of a particular tooth). That is, the system of the present invention is preferably configured to locate the vertical line 20 at various points around the periphery 26 of the tooth and then quantify the area 24 between the vertical line 20 and the variable/external tooth surface. The present invention provides that the system then uses the plurality of region 24 values to calculate and construct a three-dimensional model of the undercut/retention feature of each tooth, which can then be used to design and manufacture orthodontic aligners (the internal dimensions of the aligner are preferably configured to fit snugly and accommodate the exact three-dimensional undercut topography of each tooth). The present invention provides that the system is preferably configured to perform the above-described measurements and analysis on each tooth within the patient's dental arch (or a copy of the dental arch, e.g., a dental stone model or digital image of the patient's dental arch).

As noted above, the system and method of the present invention preferably employs the use of certain digital techniques to more accurately and efficiently identify and measure the amount of undercut (tooth morphology) for one or more teeth. The present invention provides the ability to employ various types of digital technologies. In certain preferred embodiments, for example, a three-dimensional digital image of a patient's dentition may be obtained, e.g., using digital scanning (camera) techniques. The present invention provides that the three-dimensional digital image can then be imported into a computing environment, such as a computer system that includes a central processor, memory, imaging software, and a graphical user interface. In a computing environment, the system can then be operated to perform the above-described measurements and analysis on each tooth (or those teeth to be covered by the orthodontic aligner) in the patient's arch using the three-dimensional digital image.

More specifically, within the computing environment, imaging software may be used that is configured to (1) create and locate at least one digital reference plane 18 for each tooth to be analyzed; (2) positioning at least one digit line 20 extending perpendicularly from the reference plane 18, which is further oriented to contact (and extend tangentially to) the tooth at a most prominent location 22 of the tooth (i.e., at its "height of greatest convexity"); (3) quantifying the area 24 between the vertical line 20 and the variable/outer tooth surface; and (4) repeating steps (1) - (3) for a plurality of locations around the perimeter 26 of the particular tooth to be analyzed.

The present invention provides that such measurements and systems can then be used to generate a three-dimensional model of the undercut region 24 for each of the one or more teeth (i.e., the three-dimensional model represents a compilation of each undercut region 24 that the system calculates for each of the one or more teeth). The present invention provides that the system is preferably configured to convert the three-dimensional model of the inverted concave region 24 for each of the one or more teeth into a set of dimensions related to the appropriate internal dimensions of the removable orthodontic aligner. In such embodiments, the preferred internal dimensions of the removable orthodontic aligner are configured to mate with and remain contiguously disposed with the inverted concave region of each of the one or more teeth. The present invention provides that these steps and methods of using the systems described herein are further encompassed by the present invention, as generally shown in fig. 5.

Referring now to fig. 6, when the system of the present invention is used for treatment planning and design of orthodontic aligners, the clinician may choose to fill this undercut region (identified and quantified by the system) by attaching tooth restoration material, attachment devices/brackets 28, or other materials to the teeth to facilitate adequate retention for effective tooth movement. More specifically, the present invention provides that a three-dimensional model of the undercut region 24 for each of one or more teeth can be used to identify a desired location (and size and configuration) of an attachment apparatus 28 (also referred to as an adapter) to which the attachment apparatus 28 can be attached to provide even greater retention between the orthodontic aligner and the patient's teeth. In such embodiments, the attachment devices 28 will provide additional tooth morphology so that the orthodontic aligner can better grip the underlying teeth. The present invention provides that such attachment devices 28 may further be used to facilitate various tooth movements, such as rotation, intrusion, squeezing, translation, tilting, and twisting.

Referring now to fig. 7-8, according to yet further embodiments, the systems and methods of the present invention are further configured to produce (and/or utilize) temporary or permanent dental restorations 30 (e.g., crowns) that are customized to provide a desired restorative undercut 32 for enhanced aligner retention and treatment. The present invention provides that a desired prosthetic undercut 32 can be built into the prosthesis 30 regardless of whether an aligner is used (e.g., the desired prosthetic undercut 32 can be built into the prosthesis 30 only for the possibility that the patient may select an aligner treatment at some future time).

More specifically, referring to FIG. 7, a relatively flat contoured tooth or restoration 30 (e.g., a crown) will exhibit a small amount of undercut 34 (which makes retention of the aligner more difficult); however, referring to fig. 8, a tooth or restoration 30 (e.g., a crown) having a spherical contour will exhibit a more desirable amount of undercut 32. As explained above, the larger/desired prosthetic undercut 32 (fig. 8) is used by the system to calculate a set of dimensions related to the preferred internal dimensions of the removable orthodontic aligner. In such embodiments, the preferred internal dimensions of the removable orthodontic aligner are configured to mate with and remain contiguously disposed with the desired inverted concave region 32 of each of the one or more prostheses 30. In such embodiments, a particular amount of the desired undercut region 32 for each tooth may be controlled by the clinician and operator of the system. Preferably, in such embodiments, the prosthesis 30 is made of aesthetic dental materials, such as ceramics and composite resins.

According to still other embodiments, the systems and methods of the present invention are further configured to produce aligners and prostheses that are customized to present integrated anti-reduction features (e.g., dimples, ridges, depressions, and others). In such a case, the anti-repositioning feature is configured to apply an anti-repositioning force in a particular region of the tooth (or otherwise make the repositioning motion more difficult). For example, a small bump or ridge on the distal lingual edge ridge of the tooth, located on the lower incisor (i.e., within the portion of the aligner or prosthesis applied to that area of the tooth), will prevent the tooth from undergoing rotational repositioning motion in that direction. Fig. 9-11 provide further examples of such embodiments.

In FIG. 9, for example, a rotationally misaligned tooth 36 is shown; showing the counter-rotated/corrected teeth 38 (such correction is achieved by conventional orthodontic methods); the direction of rotational reset force 40 is shown; and showing the location of the anti-reduction raised ridges 42 (in the portion of the aligner or restoration 44 applied to the orthodontic teeth 38). The present invention provides that when used to design and produce an aligner or prosthesis, the systems described herein can optionally include an anti-reduction feature of this type (to prevent the intended reduction motion). In the example shown in fig. 9, raised ridges 42 are integrally formed in portions of the aligner or prosthesis 44 to exhibit a size, configuration and position that (mechanically) counteracts the expected rotational repositioning force 40 of the underlying orthodontic teeth 38.

Similarly, fig. 10 shows another malpositioned tooth 46 (post malposition); orthodontic teeth 48; the direction of the restoring force 50 exerted on the orthodontic teeth 48; and the position of the reduction-resistant elevated ridge 52 of the aligner or prosthesis 44. In this example, the anti-reduction raised ridges 52 of the aligner 44 are configured to exhibit a magnitude and position to counteract the expected reduction force 50 of the underlying orthodontic teeth 48. Likewise, fig. 11 shows yet another malpositioned tooth 54 (an invasive tooth); orthodontic teeth 56; the direction of restoring force 58 exerted on orthodontic tooth 56; and the location of the reduction/anti-extrusion (bulging) feature 60 (and corresponding reduction/anti-extrusion feature 64) on the crown/restoration 62, the feature 64 being positioned on an aligner 66 mounted to the crown/restoration 62. The present invention provides that the foregoing examples are not exhaustive. Rather, the systems and methods described herein may be used to design and produce aligners and/or prostheses that may utilize a number of different anti-reduction features, such as ridges, dots, dimples, dents, depressions, ridges (vertical, horizontal, diagonal, and other directions), and combinations of these features, to apply a desired anti-reduction force on the underlying teeth.

The present invention provides that the systems and methods described herein preferably operate to generate a production model of the desired aligner (and/or prosthesis). For example, after a three-dimensional model of the undercut region 24 for each of one or more teeth is generated (as described above) and converted to the internal dimensions of the removable orthodontic aligner (and/or prosthesis), and likewise, once all of the desired geometry of the reduction-resistant features are defined, the system is configured to generate a production model of the desired aligner (and/or prosthesis). The production model will contain a complete digital three-dimensional model of the desired aligner (and/or prosthesis), defining all external and internal dimensions, which can then be used to produce the desired aligner (and/or prosthesis), for example, using various types of polymer and thermoforming methods known in the art.

The many aspects and advantages of the invention are apparent from the detailed specification, and thus, it is intended by the following claims to cover all such aspects and advantages of the invention which fall within the scope and spirit of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described herein. Accordingly, it is to be understood that all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed herein.