Methods of Forming Orthodontic Appliances

Abstract

Processes for forming orthodontic appliances and other dental inserts comprise scanning a patient's dental arch or a mould of a dental arch such as a traditional plaster mould, to form a digital dental arch file corresponding to the size and position of the patient's dental arch. The digital dental arch file contains data corresponding to a plurality of dimensions corresponding to portions of the patient's dental arch. The disclosed methods include the step of modifying the digital dental arch file to decrease at least one of said dimensions and then utilizing the modified digital dental arch file to form the desired orthodontic appliance and other dental insert.

Claims

1. A method of forming an orthodontic appliance comprising the steps of: scanning a patient's dental arch to form a digital dental arch file corresponding to the size and position of the patient's dental arch, said digital dental arch file containing data corresponding to a plurality of dimensions corresponding to portions of the patient's dental arch; modifying the digital dental arch file to decrease at least one of said dimensions; and utilizing said modified digital dental arch file to form a dental appliance.

2. A method of forming an orthodontic appliance according to claim 1 wherein said utilizing step comprises 3D printing.

3. A method of forming an orthodontic appliance according to claim 1 wherein said plurality of dimensions correspond to anterior, posterior, right lateral and left lateral positions of portions of the patient's dental arch.

4. A method of forming an orthodontic appliance according to claim 1 wherein said digital dental arch file comprises data corresponding to the anterior-to-posterior dimension of at least one portion of the patient's dental arch.

5. A method of forming an orthodontic appliance according to claim 1 wherein said modifying step comprises reducing the anterior-to-posterior dimension of at least one portion of the patient's dental arch.

6. A method of forming an orthodontic appliance according to claim 5 wherein said digital dental arch file comprises data corresponding to the right lateral-to-left lateral dimension of at least one portion of the patient's dental arch.

7. A method of forming an orthodontic appliance according to claim 6 wherein said modifying step comprises reducing a lateral dimension of at least one portion of the patient's dental arch.

8. A method of forming an orthodontic appliance according to claim 1 wherein said digital dental arch file comprises data corresponding to the right lateral-to-left lateral dimension of at least one portion of the patient's dental arch.

9. A method of forming an orthodontic appliance according to claim 8 wherein said modifying step comprises reducing a lateral dimension of at least one portion of the patient's dental arch.

10. A method of forming an orthodontic appliance comprising the steps of: forming a mould of a patient's dental arch; digitally scanning said mould to form a digital dental arch file corresponding to the size and position of at least a portion of said mould, said digital dental arch file containing data corresponding to a plurality of dimensions corresponding to portions of the mould; modifying the digital dental arch file to decrease at least one of said dimensions; and utilizing said modified digital dental arch file to form a dental appliance.

11. A method of forming an orthodontic appliance according to claim 10 wherein said utilizing step comprises 3D printing.

12. A method of forming an orthodontic appliance according to claim 10 wherein said plurality of dimensions correspond to anterior, posterior, right lateral and left lateral positions of portions of the patient's dental arch.

13. A method of forming an orthodontic appliance according to claim 10 wherein said digital dental arch file comprises data corresponding to the anterior-to-posterior dimension of at least one portion of the mould.

14. A method of forming an orthodontic appliance according to claim 10 wherein said modifying step comprises reducing the anterior-to-posterior dimension of at least one portion of the mould.

15. A method of forming an orthodontic appliance according to claim 14 wherein said digital dental arch file comprises data corresponding to the right lateral-to-left lateral dimension of at least one portion of the mould.

16. A method of forming an orthodontic appliance according to claim 15 wherein said modifying step comprises reducing a lateral dimension of at least one portion of the mould.

17. A method of forming an orthodontic appliance according to claim 10 wherein said digital dental arch file comprises data corresponding to the right lateral-to-left lateral dimension of at least one portion of the mould.

18. A method of forming an orthodontic appliance according to claim 17 wherein said modifying step comprises reducing a lateral dimension of at least one portion of the mould.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG. 1 shows a clinical dental arch.

[0011] FIG. 2 illustrates a conventional 3D model of the clinical dental arch shown in FIG. 1.

[0012] FIG. 3 shows a computer processor for forming a digital dental arch file and for processing the digital dental arch file to impart the desired shrinkage.

[0013] FIG. 4 shows the 3D model resulting from the processing to impart dimensional shrinkage.

[0014] FIG. 5 shows the printing of the shrunk scan using a 3D printer.

[0015] FIG. 6 shows the improved “shrunken” printed mould 2

[0016] FIG. 7 shows the clear orthodontic appliance 3 formed over a shrunken printed mould 2

[0017] FIG. 8 shows the clear orthodontic appliance 3 isolated from the shrunken mould 2

[0018] FIG. 9 shows the clear orthodontic appliance 3 fitted snugly on the clinical dental arch shown in FIG. 1.

[0019] FIG. 10 illustrates a dental arch without shrinkage.

[0020] FIG. 11 illustrates a dental arch model formed with shrinkage and an orthodontic appliance (aligner) formed on top of the shrunken model.

[0021] FIG. 12 illustrates a screen shot of a processor applying shrinkage.

DETAILED DESCRIPTION

[0022] FIG. 1 illustrates a clinical arch 1 with malocclusion (mild crowding) which requires orthodontic treatment for levelling and alignment.

[0023] FIG. 2 illustrates the initial intraoral raw scan of the clinical arch 1. An intraoral scan is taken by a dentist or orthodontist over which a functional orthodontic appliance is made. This “scan” is a positive mould which is the product of the 3D printing process.

[0024] FIG. 3 illustrates the processing of initial data which is in the form of raw intraoral scan sent from a dentist or an orthodontist. The initial scan is referred to herein as a digital dental arch file. The digital dental arch file contains data corresponding to a plurality of dimensions corresponding to portions of the patient's dental arch. A percentage shrinkage or a predetermined dimensional shrinkage, e.g. 0.15 mm is applied to at least a portion of the initial digital dental arch file before the last stage of processing i.e. 3D printing. The percentage of shrinkage is preferably about 0.5 to about 3 percent. A dimensional shrinkage is preferably about 0.02 mm to about 0.25 mm, and more preferably about 0.10 to about 0.20 mm.

[0025] According to one method, shrinkage is applied to reduce the overall dimensions of teeth & surrounding tissues.

[0026] According to another method, shrinkage is applied about a central anterior-posterior axis running through the center of the dental arch.

[0027] According to a still further method, shrinkage is applied to the portions of the digital dental arch file around the center of each tooth so that the resulting appliance fits more snuggly on each tooth but the centered spacing between each tooth does not change.

[0028] FIG. 4 illustrates the shrunken 3D scan. A very slight change in dimensions is done to improve retention of appliance only.

[0029] FIG. 5 illustrates the printing of shrunken 3D scan using a 3D printer into physical mould 2 over which orthodontic appliance will be thermoformed.

[0030] FIG. 6 illustrates the printed shrunken mould 2. This is a template for fabrication of an orthodontic appliance.

[0031] FIG. 7 illustrates the orthodontic appliance 3 thermoformed over the shrunken mould 2.

[0032] FIG. 8 illustrates the orthodontic appliance 3 isolated from the shrunken mould 2.

[0033] FIG. 9 illustrates orthodontic appliance 3 which was formed over the shrunken mould 2, now placed over the patient's clinical dental arch 1 of relatively larger size. As the size of clinical arch 1 is larger and the appliance 3 is slightly shrunk, the appliance is tightly adapted onto the clinical arch 1.

[0034] FIG. 10 illustrates a dental arch without shrinkage.

[0035] FIG. 11 illustrates a dental arch model formed with shrinkage and an orthodontic appliance (aligner) formed on top of the shrunken model.

[0036] FIG. 12 illustrates a screen shot of a processor applying shrinkage along the x-axis and the y-axis, but not the z-axis, to an entire dental arch. As illustrated by this screenshot, with a computer interface the extent of shrinkage applied can be controlled by the doctor or technician. The person providing the input can determine to which portions of the resulting dental arch the shrinkage will be applied. In this illustrated example, shrinkage is being applied to the entire dental arch along the x-axis and the y-axis, but not along the z-axis. In each instance, 0.15 mm of shrinkage is being applied.

[0037] By adding a relatively minor percentage or dimensional amount of shrinkage in initial scan before printing the file into the positive dental mould which will be used for fabrication of an appliance provides the formation of a more retentive (snug fit) appliance having enhanced contact with the patient's teeth. This snug fit appliance is capable of exerting more optimum orthodontic forces (functionally improved) for better treatment outcomes