Systems and processes for forming anatomical features in dentures

Abstract

The system of a preferred embodiment uses a process whereby a true replication of the patient's jaw structure is created in a digital three dimensional model. This true replication is then used to precisely locate and/or copy the anatomical landmarks of the patient for use in fabricating a denture base for use in a denture for the individual patient. This system is able to create a denture with precisely located features corresponding to the anatomical landmarks of the patient with little manual intervention.

Claims

1. A computer-implemented method for creating anatomical features in a denture, the method comprising: creating a three dimensional digital model of the mouth and jaw structure of a patient; identifying anatomical landmarks of the patient on the digital model via a software system or a user of the software system, the step of identifying anatomical landmarks selected from the group comprising identifying a labial frenum or identifying a buccal frenum; creating a digital model of a denture base that includes anatomical features based upon the anatomical landmarks, wherein the anatomical features is selected from a group comprising of a notch based upon the labial frenum or a notch based upon the buccal frenum; and fabricating a denture base that corresponds to the digital model of the denture base; wherein said step of identifying the anatomical landmarks includes: identifying the buccal reflection; and the step of creating a digital model of a denture base that includes the identified anatomical landmarks further comprises creating an undercut adjacent a buccal roll corresponding to the buccal reflection.

2. The method of claim 1 wherein said step of identifying the anatomical landmarks includes: identifying a line between the hard and soft palates; and the step of creating a digital model of a denture base that includes the anatomical features further comprises creating a post dam on the denture base model.

3. The method of claim 1 wherein said step of identifying the anatomical landmarks includes: identifying a trim line; and the step of creating a digital model of a denture base that includes the identified anatomical landmarks further comprises creating a margin or trim line along a buccal reflection.

4. The method of claim 1 wherein said step of identifying the anatomical landmarks includes: identifying rugae; and the step of creating a digital model of a denture base that includes the identified anatomical landmarks further comprises creating a true rugae on the digital model.

5. The method of claim 1 wherein said step of identifying the anatomical landmarks includes: identifying areas for thinning on the digital model of the denture base; and the step of creating a digital model of a denture base that further comprises the identified anatomical landmarks includes selectively thinning the denture base on the digital model of the denture base.

6. The method of claim 1 wherein said step of identifying the anatomical landmarks includes: identifying areas of soft tissue around the teeth of the digital model; and the step of creating a digital model of a denture base that includes the identified anatomical landmarks further comprises creating soft tissue lines around a gum line around the teeth to simulate roots of the tooth.

7. The method of claim 1 wherein said step of identifying the anatomical landmarks includes: identifying areas for placement of implant supports on the digital model; and the step of creating a digital model of a denture base that includes the identified anatomical landmarks further comprises locations for implant-supports on the digital model.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 illustrates a workflow diagram of an embodiment of the present invention.

(2) FIG. 2 is an inner and outer scan of a bite impression.

(3) FIG. 3 is a rendition of a three dimensional model of a denture base.

(4) FIG. 4 is an illustration of the mandibular arch

(5) FIG. 5 is an illustration of the maxillary arch.

(6) FIG. 6 is an illustration of a rear perspective view of a denture base of a preferred embodiment of the present invention.

(7) FIG. 7 is a front perspective view of the denture base.

(8) FIG. 8 is top perspective view of the denture base.

(9) FIG. 9 is a rear view of the denture base.

(10) FIG. 10 is a top view of the lower denture base.

(11) FIG. 11 is an illustration of a denture base with implant housings.

DETAILED DESCRIPTION

(12) The present invention provides systems and process for the fabrication of dentures that correspond to anatomical landmarks of the patient. Descriptive embodiments are provided before for explanatory purposes. It is to be expressly understood that the present invention is not be limited to these descriptive embodiments. Other embodiments are considered to be within the scope of the present invention, including without limitation the use of the present invention for other applications, such as denture duplication, dental implants, and other dental and orthodontic applications. The descriptions below discuss the systems of the present invention as used in dental labs, but it is to be expressly understood that these systems could also be implemented in the dentist office or through a network allowing interaction between the dentist and the dental lab through the systems. The processes and systems of the present invention may also be used in combination with all or parts of the following co pending applications filed on Nov. 3, 2010, entitled System and Process for Optimization for Dentures, Ser. No. 13/823,662; System and Process for Duplication of Dentures, Ser. No. 13/823,466; Combination Tool for Measuring Dental Anatomical Features, Ser. No. 13/249,910; and Removable Tool for Denture Uses, Ser. No. 12/939,143; all of which are hereby incorporated herein by reference.

(13) Overview

(14) The terms denture base generally refers to the part of a denture that fits the oral mucosa of the basal seat, restores the normal contours of the soft tissues of the dentulous mouth, and supports the artificial teeth. The term denture refers to the denture base with the artificial teeth attached. The term anatomical landmarks refers to the structures on the anatomy of the wearer that define the periphery of the denture. The term anatomical features includes the features corresponding to the anatomical landmarks of the wearer as well as functional and aesthetic features that are created in the denture.

(15) The system of a preferred embodiment uses a process whereby a true replication of the patient's jaw structure is created in a digital three dimensional model. This true replication is then used to precisely locate and/or copy the anatomical landmarks of the patient for use in fabricating a denture base for use in a denture for the individual patient.

(16) In one preferred embodiment as described in the flow chart of FIG. 1, cans of the patient's bite impressions are taken and a number of measurements from the patient on their initial visit. These measurements are based on the anatomical features of the patient. The dentist may also provide information regarding to the selection of the teeth. This information is transmitted to the dental lab where the system creates a digital three dimensional model of the patient's jaw structure from the scans and from the measurements. It is to be expressly understood that other methods of creating a digital three dimensional model of the jaw structure may be used as well. The process described herein is only one embodiment for doing so.

(17) Once the digital model has been created, denture teeth are selected from a library or fabricated directly for that digital model. This can be based on using a library and selecting the best denture teeth, through an optimization process as described in the above identified co pending application, or through another process.

(18) The system of a preferred embodiment of the present invention either creates a digital denture base or modifies an existing digital denture base to create the best fit in the patient by precise use of the anatomical landmarks of the patient. These include locating the ideal location of the post dam, locating and forming the notches for the labial and buccal frenums, creating the idealized margins along the buccal reflection, creating the idealized gum line and root structures, creating a true copy of the patient's palatial rugae and duplicating that structure on the denture base, locating the soft tissue lines of the patients mouth, locating areas for dental implant structures and any other features that are useful or desirable from either a functional or aesthetic standpoint.

(19) A description of one process and system for preforming the claimed inventions is described below. In this preferred embodiment, a digital three dimensional model of the patient's mouth and jaw structure is created from scanned bite impressions and from precise measurements of the anatomical features of the patient.

(20) Measurement Process

(21) The dentist obtains data regarding several anatomical landmarks of the patient to send to the dental lab. First, the dentist takes the bite impressions. This can be done by using an upper bite impression tray, a lower bite impression tray and a centric relationship tray or a triple bite impression tray that simultaneously takes upper and lower and centric bite impressions. The resulting bite impressions are digitally scanned as shown in FIG. 2 and transmitted to the lab or directly into the system. The bite impressions provide the bite registration, the prepared area and the opposing teeth. Alternatively, or in conjunction with this process, an intraoral digital scanning may be done.

(22) The dentist also takes additional measurements of anatomical features of the patient. These include, without limitation, the vertical height relation to the upper and lower bite alignment; the lip support of the patient; the smile line of the patient; the centric relationship of the patient; and the midline measurement. Other measurements may be taken as well.

(23) The lip line measurement is intended to provide a measurement of the upper lip from the anterior papilla at rest. This is traditionally measured by a papillameter which consist of a vestibule shield, incisive papilla rest and an vertical handle with measurement increments.

(24) The smile line measurement can also be determined by the papillameter. The device is inserted into position and the patient is requested to smile so that the lip line at that position from the anterior papilla can be measured.

(25) The midline is determined from typically from the existing intraoral anatomic structures, usually the maxillary anterior labial frenum.

(26) The vertical height dimension is typically determined from measurements taken from nose and chin reference points. Measurements of the vertical height are taken at rest and of the vertical dimension of occlusion.

(27) A centric tray is commonly used to take a double arch registration to record vertical and centric jaw registration.

(28) The occlusal plane is an orientation of the position of an imaginary occlusal plane which theoretically touches the incisal edges of the incisors and tips of the occluding surface of the posterior teeth. A normal occlusal plane extends parallel to a line drawn from the tragus of the ear to the ala of the nose and parallel to the interpupillary line (Kamper's Line). This ensures that the patient will not dislodge the lower denture, particularly while eating and not bite the lateral borders of the tongue. Tools for measuring the occlusal plane typically include a thin flat plane have a curved bite piece and a pair of laterally and distally extending wings projecting from the bite piece.

(29) There are individual tools for each of these measurements. A single tool for obtaining all of these measurements is disclosed in co-pending application Ser. No. 14/798,717 and is incorporated by herein above. In a preferred embodiment of the present invention, this tool is used to supply the necessary measurements for the optimization process for designing a denture mold.

(30) The dentist also selects the teeth to be fitted into the denture base. Typically, the dentist will use a facial meter, anterior tooth selection guide and a library catalog to determine the appropriate teeth. Other methods may be used as well along with the determination of the appropriate shading of the teeth.

(31) The scan, measurements and teeth selection are then transmitted to the dental lab or directly into the system.

(32) System

(33) The scanned images 12, 14 of the bite impressions and the measurements are then transmitted into a system that will process this information to create the digital three dimensional model. Systems for creating such digital three dimensional models are disclosed in U.S. Pat. No. 6,616,444, assigned to Ormco Corporation and patents relating to that patent, U.S. Pat. No. 6,851,949, assigned to OraMetrix, Inc. and patents relating to that patent; and U.S. Pat. No. 7,433,810, assigned to Align Technology, Inc. and patents relating to that patent, all of the above cited patents and patents and published patent applications relating to them are incorporated herein by reference. These systems are disclosed for use with orthodontic appliances. The present invention takes the information from these systems and utilizes the additional information described above in regard to the measurements of the patient's anatomy and impressions to create a digital model 20 as shown in FIG. 3 for use with creating and optimizing a denture base.

(34) The system of a preferred embodiment further includes the capability to uniquely distinguish certain anatomical landmarks of the patient from this digital model. These landmarks are used to create features that are registered to ensue their incorporation into the digital model of a denture base from which a denture base is fabricated. The anatomical landmarks of the mandibular arch, as shown in FIG. 4 and of the maxillary arch as shown in FIG. 5 are critical for the proper fit of the denture.

(35) One anatomical landmark that is determined preferably by the system, but alternatively by a technician using the system is the line 50 as shown in FIG. 5 between the hard and soft palates. This line is irregular and difficult to determine precisely using current techniques. This line can be determined from the digital model based on the pressure or density in which the bite impressions are formed. For example, the impression will have a greater density at the hard palate due to the greater pressure applied upon it compared to the pressure exerted by the soft palate when the patient bites down on the impression compound. The line may also be readily noticeable simply due to this change in pressure between the palates on the impression compound. This can show up as different colors on the digital model or simply be registered by the system. Other techniques may be used as well. The system then is able to create the post dam along that line of demarcation. This will ensure a tight seal to create a vacuum between the denture and palate to secure the denture.

(36) Another anatomical landmark that is determined is the labial frenum 52. The precise location of the labial frenum can be registered for the creation of the notch 72 in the denture base as shown in FIG. 7. The buccal frenums 54, 56 are also located and registered to create notches 74, 76 in the denture base for these frenums as well. This minimizes dislocation of the denture during speech and improves the comfort, fit and aesthetics of the denture.

(37) The buccal reflection 66 of the patient can be located as well by changes in density due to changes in pressure on the impression compound or simply by the change in structure of the impression. From this precise location of the buccal reflection, the buccal roll 59 can be formed on the denture base. Then, an undercut can be formed in the denture base on the buccal roll. The tissue and muscles surrounding the buccal roll will engage into the undercut to form a gripping region to further secure the denture.

(38) The margin, or trim line along the buccal reflection 66, as shown in FIG. 4 can be precisely located. This reduces the time for technician to carve or trim the denture base after molding and improves the comfort. This margin line can also be registered by the system to be included into the digital denture base and denture base.

(39) The soft tissue lines are also determined from the digital model so that they can be registered and included into the denture base for fabricating the base. In particular, the gingival margin where the gum ends on the teeth and the soft tissue surrounding the roots of the teeth below the gum are mimicked on the denture base. These soft tissue lines are largely for aesthetic reasons but also may improve the comfort to the patient.

(40) The rugae 78 of the individual patient can also be uniquely copied for use in the denture base. Each rugae is unique to an individual and affect the speech and comfort of the individual. The rugae is also used to identify individuals for forensic purposes. The rugae is copied on the tissue side and mimicked on the teeth side. The rugae can also be accentuated or diminished as needed to improve the speech or comfort of the patient. The rugae is registered by the system for copying into the digital denture base.

(41) The digital denture model can also be used to identify locations on the optimal denture base for implant supports to be inserted. These supports can be housings such as housings 90 shown in FIG. 11 or bars or other types of supports.

(42) The digital denture model can also be used to identify areas on the denture base which can be thinned to increase comfort while not compromising the structural integrity of the denture base. This can be in the arch, the palatial region and around the teeth pockets. A finite element analysis can also be used to determine these areas.

(43) Other features can be identified and registered by the system if desired. In one embodiment, denture teeth are selected from a library that best fits the digital denture base and modified if necessary. In an alternative embodiment, the denture teeth are fabricated directly from information based on the digital denture base model.

(44) Examples of a denture base with the features formed therein are illustrated in FIGS. 6-11. Denture base 70 includes a notch 72 for the labial frenum as well as notches 74, 76 for the buccal frenum. A true rugae 78 that mirrors the patient's rugae is formed as well. Pockets 80 are formed, preferably by milling or rapid prototyping, for the installation of the teeth. The geometry of these pockets has been critically designed for the best occlusal fit of the teeth. Post dam 82 has been formed precisely along the line of between the hard and soft palate. The margins or gum lines 84 and root structures 87 have also been created as well. Critical areas have also been selected to thin the denture base, particularly along the arch palate and teeth pockets. An buccal roll 86 in FIG. 8 may also be formed for engagement along the buccal reflection 66 as well. A lower denture 100 is also shown in FIG. 10.

(45) The denture base is selected or fabricated and the teeth are temporarily installed. This try-in denture is then shipped to the dentist for a patient try-in. If the fit is not satisfactory, then the denture is used as a secondary impression tray and a new impression is created and scanned. This scan along with any additional changes in measurement data is put back into the system. A new denture base is created. The teeth are once again temporarily installed and the denture is ready for another try-in with the patient.

(46) This process is continued until the patient and dentist are satisfied with the denture. Once the denture has been deemed satisfactory, the denture is shipped back to the lab so that the teeth can be permanently installed and the final finish and polish procedures are performed. The finished denture is then shipped to the dentist for the patient final try-in and acceptance.

(47) The system of a preferred embodiment of the present invention can be implemented in many forms. The above description below is simply one example of an implementation of the system.

(48) It is to be expressly understood that the above description is intended only for explanatory purposes and is not meant to limit the scope of the claimed inventions. Other embodiments are considered to be within the scope of the claimed inventions.