Method For Making A Virtual Computer Model of the Jaws

Abstract

Methods and systems for making a computer model of a patient's jaws on the basis of digital information from computed tomography and non-radiographic digital imaging of the patient's teeth or dental casts of their teeth.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of an exemplary CT bite plate with bite registration material.

FIG. 2 is a schematic view illustrating the positioning of a patient in a cone beam CT machine with the CT bite plate in the mouth.

FIG. 3 is a flow chart showing an exemplary process for CT imaging the patient with the CT bite plate, the process of selecting points on radiographic markers, and process of eliminating teeth and radiographic scatter

FIGS. 4A and 4B are flow charts showing exemplary processes of non-radiographic imaging of a patient's teeth and radiographic markers. Joining CT data sets with obtained non-radiographic data sets is also illustrated.

FIG. 5 illustrates an exemplary cast holding device and exemplary reference plates.

FIG. 6 is a schematic of an exemplary non-radiographic imaging system.

FIG. 7 is a schematic of an exemplary radiographic marker.

FIGS. 8A and 8B are illustrations of exemplary rendered data from CT imaging with the radiograph scatter present (as in FIG. 8A) and removed (as in FIG. 8B).

FIG. 9 illustrates exemplary non-radiographic data set of the lower teeth being joined to an exemplary CT data set of the mandible using the radiographic markers for orientation.

FIG. 10 is a schematic of an exemplary perfected virtual model and the axis of rotation for the lower jaw.

FIGS. 1A and 11B are flow charts showing exemplary processes for creating movement for the lower jaw in a virtual model.

FIG. 12 is a schematic diagram of an exemplary digital recorder attached to the CT bite plate.

FIG. 13 is a schematic diagram of the exemplary digital recorder attached to the lower bite fork.

FIG. 14 is an illustration of movement of an exemplary lower jaw to record and locate the axis of rotation of the lower jaw.

FIGS. 15A and 15B are illustrations of an exemplary virtual model with soft and hard tissues rendered in relation to the horizontal plane.

FIG. 16 is a block diagram of an exemplary system usable to accomplish the methods disclosed herein.

Claims

1. A method of creating a virtual computer model of a patient's upper jaw and mandible for kinematic analysis, comprising: acquiring non-radiographic data representing a digital model of the patient's upper and lower teeth and representing radiographic markers;acquiring CT data representing the patient's upper jaw and mandible and representing radiographic markers;reformatting the CT data to generate a 3D CT image;eliminating radiographic scatter from the CT image;aligning the radiographic markers of the CT image with the radiographic markers of the digital model to move the digital model of the upper and lower teeth into a proper anatomic position in the CT image; andassessing kinematics of the mandible relative to upper jaw on the CT image.

2. The method of claim 1, wherein assessing kinematics includes determining a rotational center of the mandible of the CT image.

3. The method of claim 2, wherein the determining a rotational center of the mandible includes separating a mandible image from the CT image to allow for movement of the mandible image independent of the remaining CT image.

4. The method of claim 2, wherein the determining a rotational center includes determining an axis of rotation of the mandible using spatial positions of imaged condyles.

5. The method of claim 4, wherein the determining an axis of rotation includes selecting points with an input device on or around articulating surfaces of the imaged condyles.

6. The method of claim 5, including rotating the mandible image about the axis.

7. The method of claim 4, including determining lateral and protrusive movements of the mandible image relative to the remaining CT image.

8. The method of claim 2, wherein the determining a rotational center includes recording opening, lateral, and protrusive movements of the patient's mandible with a digital recorder.

9. The method of claim 8, wherein the recording opening, lateral and protrusive movements includes associating sensors with a CT bite plate associated with the mandible and moving the patient's mandible while recording displacement of the sensors.

10. The method of claim 1, wherein the radiographic markers are spheres and the aligning the radiographic markers includes aligning a specific point on the spheres.

11. The method of claim 1, wherein acquiring non-radiographic data includes directly scanning the patient's upper and lower teeth in the patient's mouth.

12. The method of claim 11, wherein scanning the patient's upper and lower teeth is accomplished with one of a photographic, light, laser, and holographic imaging system.

13. A method of creating a virtual computer model of a portion of a patient's head, comprising: placing a CT bite plate between upper and lower teeth in the patient's mouth, the CT bite plate having associated radiographic markers;imaging the teeth in the patient's mouth, without imaging casts of the teeth, using a non-radiographic imaging system to acquire non-radiographic data representing a digital model of the upper and lower teeth and the radiographic markers;formatting the non-radiographic data to generate a 3D digital model;acquiring CT data representing the patient's mandible and upper jaw and representing the radiographic markers;formatting the CT data to a 3D CT image;eliminating radiographic scatter from the CT image;aligning the radiographic markers of the CT image with the radiographic markers of the digital model to move the image of the digital model into a proper anatomic position in the CT image.

14. A dental apparatus, comprising: a bite registration section formed of a radiolucent material and being configured to fit within a patient's mouth and mate with the patient's teeth;a central forward projection extending from the bite registration section configured to extend between lips when the bite registration section is in the mouth;an exterior portion configured to reside outside the mouth, the exterior portion being attached to the central forward projection; andat least three non-linear radiographic markers disposed on the exterior portion and having a radiographic density that makes them visible in the CT data.

15. A method of creating a virtual computer model of a patient's head, comprising: placing a CT bite plate between upper and lower teeth in a patient's mouth, the CT bite plate having associated radiographic markers disposed to be above or below a plane of occlusion defined by the patient's upper and lower teeth;scanning the patient's teeth and the CT bite plate with a non-radiographic imaging system to acquire non-radiographic data representing a digital model of the upper and lower teeth and the radiographic markers;formatting the non-radiographic data to generate a 3D digital model;scanning the patient's upper and lower teeth, mandible, upper jaw, and the CT bite plate with a CT machine to acquire CT data representing the patient's teeth and surrounding tissue and representing the radiographic markers;formatting the CT data to a 3D CT image;eliminating radiographic scatter and the upper and lower teeth from the CT image;aligning specific points on the radiographic markers of the CT image with corresponding specific points on the radiographic markers of the digital model to move the image of the digital model into a proper anatomic position in the CT image;separating the mandible portion of the CT image from the upper jaw portion of the CT image to allow for movement of the mandible image independent of the upper jaw portion image;determining an axis of rotation of the mandible image corresponding to articulation points on the CT image;determining lateral and protrusive movements of the mandible image relative to the upper jaw portion image; androtating the mandible of the CT image about the axis of rotation.

16. A system for creating a virtual computer model of a patient's upper jaw and mandible for kinematic analysis, comprising: means for acquiring non-radiographic data representing a digital model of the patient's upper and lower teeth and representing radiographic markers;means for acquiring CT data representing the patient's upper jaw and mandible and representing radiographic markers;means for reformatting the CT data to generate a 3D CT image;means for eliminating radiographic scatter from the CT image;means for aligning the radiographic markers of the CT image with the radiographic markers of the digital model to move the digital model of the upper and lower teeth into a proper anatomic position in the CT image; andmeans for assessing kinematics of the mandible relative to upper jaw on the CT image.

17. A system for creating a virtual computer model of a patient's head, comprising: a bite plate disposable between teeth in a patient's mouth, the bite plate having associated radiographic markers;means for imaging the teeth in the patient's mouth, without imaging casts of the teeth, using a non-radiographic imaging system to acquire non-radiographic data representing a digital model of the upper and lower teeth and the radiographic markers;means for formatting the non-radiographic data to generate a 3D digital model;means for acquiring CT data representing the patient's mandible and upper jaw and representing the radiographic markers;means for formatting the CT data to a 3D CT image;means for eliminating radiographic scatter from the CT image; andmeans for aligning the radiographic markers of the CT image with the radiographic markers of the digital model to move the image of the digital model into a proper anatomic position in the CT image.

18. A method of creating a treatment plan for a dental patient, comprising: orienting the patient's head in a CT imaging system such that the position of the head is in a natural position relative to a horizontal reference;scanning the patient's head with the CT imaging system to acquire CT data;reformatting the CT data to create a 3D soft tissue model of the soft tissues and to create a 3D hard tissue model of the hard tissues of the head; andperforming aesthetic diagnostic evaluation using the soft tissue and hard tissue models of the patient's head in the natural position.

19. A method of reproducing in a computer model actual movement of a mandible relative to an upper jaw of a patient, comprising: attaching a first sensor to the patient's mandible;detecting the position of the first sensor relative to the upper jaw with a second sensor associated with the head of the patient;displacing the patient's mandible relative to the upper jaw in an open and close direction;recording first digital data representing the location of the upper jaw and mandible during the displacement of the patient's mandible in the open and close direction;displacing the patient's mandible relative to the upper jaw in a lateral direction and in a protrusive direction;recording second digital data representing the lateral and protrusive locations of the upper jaw and mandible during the displacement of the mandible in the lateral and protrusive directions;determining a rotational center of the mandible;recording the rotational center as third digital data;introducing the first, second, and third digital data to the computer model; andreproducing the movement of the mandible in the computer model using the first, second, and third digital data.

20. A method of creating a treatment plan for a dental patient, comprising: placing a CT bite plate in the patient's mouth prior to scanning the patient's head, the CT bite plate having radiographic markers disposed thereon;orienting the patient's head in a CT imaging system such that the position of the head is in a natural position relative to a horizontal reference;scanning the patient's head with the CT imaging system to acquire CT data;reformatting the CT data to create a 3D soft tissue model of the soft tissues and to create a 3D hard tissue model of the hard tissues of the head; anddetermining a rotational center of the mandible of the hard tissue model by separating a mandible image from the hard tissue model to allow for movement of the mandible image independent of the remaining hard tissue model;performing aesthetic diagnostic evaluation, including measuring spatial relationships between facial features on the hard tissue model and the soft tissue model in the natural position; anddetermining a treatment plan for the patient based upon the rotational center of the mandible and the measured spatial relationships.