A method for designing implant positions in edentulous regions using artificial intelligence technology

Abstract

The application discloses a design method for implant position in edentulous area by using artificial intelligence technology, and comprises the following steps: step 1, establishing a standard crown; step 2, constructing a standard dentition form; step 3, acquiring patient's anatomical information and identifying personalized dentition; step 4, determining the future crown position in the edentulous area; and step 5, acquiring the crown center axis, i.e. the future ideal implant axis position. The application avoids the influence of factors such as measurement error and subjective speculation on the preoperative implantation, guarantees the scientificity, accuracy and feasibility of the preoperative design, automatically presents the best posture of the implant position and angle in the three-dimensional space, more intuitively displays the design of the implantation scheme, is beneficial to the communication between doctors and patients, and saves the clinical working time of doctors and improves the working efficiency.

Description

Technical Field

[0001] This invention relates to the field of oral medical technology, and more specifically to a method for designing implant placement in edentulous areas using artificial intelligence technology. Background Technology

[0002] Dental implants correctly restore the shape and function of teeth, providing good retention, support, and stability. They are beneficial to the health of oral soft and hard tissues, durable, and achieve a harmonious and aesthetically pleasing appearance. The number and size of dental implants affect the type of superstructure and the design of the support force in the implant prosthesis. Implant placement is a fundamental condition for assessing implant success. Based on the principles of developing an implant plan according to the restoration plan, the implant placement design in dental implant restoration should consider the following aspects: 1. To prevent nerve damage, the bone thickness at the base of the implant should be greater than 1-2 mm from the upper edge of the mandibular nerve canal wall and the upper edge of the mental foramen; 2. The thickness of the buccal and lingual bone plates in the implant placement area should exceed the implant diameter by at least 2 mm, i.e., at least 1.5 mm on the buccal side and at least 0.5 mm on the lingual side; 3. The optimal distance between the implant and the adjacent natural tooth should be greater than 1.5 mm, the distance between the axes of the two implants should be greater than 6-8 mm, and the distance between the jaw and gum should be greater than 6 mm.

[0003] Currently, there are still some problems with implant placement design in clinical practice: 1. Clinicians often subjectively plan the implant procedure based on their professional knowledge and the patient's bone volume; 2. There are no reference boundaries for designing and adjusting the mesial, distal, buccal, and lingual distances of the implant; 3. The design process is subject to not only manual errors by the operator but also measurement errors due to the two-dimensional perspective. To address these issues, based on our oral professional knowledge and combined with digital intelligent technology, we have developed software that can automatically design implants. The aim of this software is to avoid subjective assumptions and minimize errors caused by subjective placement and manual measurement. Furthermore, it automatically presents the optimal position and angle of the implant in three-dimensional space, providing a more intuitive display of the implant design and facilitating communication between clinicians and patients. Summary of the Invention

[0004] The purpose of this invention is to provide a method for designing implant placement in edentulous areas using artificial intelligence technology, in order to solve the above-mentioned problems.

[0005] This invention provides a method for designing implant placement in edentulous areas using artificial intelligence technology, comprising the following steps: Step 1: Create a standard dental crown; Step 2: Constructing the standard dentition morphology Based on the length and width of the dentition, the β function is used to fit the normal occlusal arch morphology or the Bonwill-Hawley arch morphology diagram is used to construct the parabolic arch morphology. Based on the standard crowns obtained in step 1, the teeth are arranged to construct the standard dentition morphology. Step 3: Obtain patient anatomical information and identify personalized dentition. Step 4: Determine the patient's occlusal plane, and then match the digital standard dentition with the patient's dentition morphology to determine the future crown position in the edentulous area; Step 5: Obtain the central axis of the crown, i.e., the ideal axis position of the future implant. Once the future crown position is determined, the edges of each cross-section of the crown are identified, and the center point of the image is automatically calculated. The center point of each layer can be displayed in three-dimensional space. The straight line closest to these points is calculated using the least squares method, which is the axis of the crown. The crown axis is extended further to become the center line of the implant's long axis, thus determining the implant position.

[0006] As a further preferred option of the above scheme In step 2, the method of fitting the normal occlusal arch shape with a β function to construct the parabolic shape of the dental arch is as follows: the contact point of the central incisor, the cusps of the bilateral canines, and the distobuccal cusps of the bilateral second molars are selected; the curve is determined by five points: the contact point of the central incisor, the cusps of the bilateral canines, and the distobuccal cusps of the bilateral second permanent molars. The general form of the β function is: Y = D[1 - (2X / D)] 2 ] e Where: D is the width of the second permanent molar, which is the distance between the distal buccal cusps of the two second permanent molars; w is the depth of the second permanent molar, which is the distance from the incisor contact point to the line connecting the distal buccal cusps of the two second permanent molars; e is obtained by solving for the position of the canines, so that the distance from the curve to the cusps of the two canines is the shortest and equal.

[0007] As a further preferred option of the above scheme The method for constructing the parabolic shape of the dental arch using the Bonwill-Hawley dental arch morphology diagram in step 2 is as follows: First, construct the x and y coordinate axes. Then, construct points A and C according to AC = (total width of the two anterior teeth + 3 mm) / 2. With point H(0, -AC) as the center and AC as the radius, construct an arc with a central angle ranging from 30° to 150°. Then, with point A as the center and 57.15 mm as the radius, construct an arc with a central angle ranging from 180° to 360°. The resulting curve is the basic morphology diagram of the individual dental arch.

[0008] As a further preferred option of the above scheme In step 2, the length of the dentition is the vertical distance between the line connecting the most prominent points of the labial side of the left and right central incisors and the line connecting the most prominent points of the distal side of the last teeth on the left and right sides of the dentition, and the width of the dentition is the distance between the distal buccal apex points of the bilateral second permanent molars.

[0009] As a further preferred option of the above scheme The method for obtaining the patient's anatomical information in step 3 is as follows: The patient wears a facebow and assumes the occlusal position. The physician places the external auditory canal support ball into both external auditory canals and slowly applies pressure. The patient is instructed to signal the physician when they feel slight pressure. The screws between the facebow and the bow body are tightened to prevent it from moving left or right. At this time, the front part of the facebow is parallel to the line connecting the pupils on both sides, and the side part is parallel to the line connecting the nasal ala and tragus on the same side, and the height of both sides is kept consistent. The patient bites down on the optical resin occlusal plate, and a CBCT scan is taken to obtain information on the patient's jawbone, dentition, and occlusal plane.

[0010] As a further preferred option of the above scheme The method for matching the digital standard dentition with the patient's dentition morphology in step 4 is as follows: a phase correlation matching algorithm is used for coarse matching, and then least squares and phase correlation matching are used to correct the corresponding point pairs of the coarse matching under the sequence image window. The correlation coefficient is calculated and compared, and the magnitude of the correlation coefficient is used as an indicator to measure whether the corresponding matching is correct. The matching result with the largest correlation coefficient is selected as the final result.

[0011] The beneficial effects of this invention are as follows: 1. Each step in this software development plan is based on professional oral knowledge and is restoration-oriented in defining the future implant position. Combined with digital intelligent technology, it automatically generates the ideal implant center axis, avoiding subjective assumptions and minimizing errors caused by subjective placement, manual measurement, and other steps, thus ensuring the scientific and accurate implant position. 2. The software automatically completes the implantation design, which greatly shortens the preoperative design time and reduces the workload of clinicians; at the same time, it retains the manual design function, which allows clinicians to confirm and modify the implantation position given by the software according to the patient's characteristics, thus further ensuring the accuracy and feasibility of the implantation position. 3. Furthermore, it automatically presents the optimal position and angle of the implant in three-dimensional space, providing a more intuitive display of the implantation plan design and facilitating clinical doctor-patient communication. Detailed Implementation

[0012] The present invention will be further illustrated below with reference to specific embodiments. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0013] Example 1 This embodiment provides a method for designing implant placement in edentulous areas using artificial intelligence technology, including the following steps: Step 1: Establishment of a standard dental crown Based on the anatomical shape of permanent teeth described in "Plaster Tooth Carving Training Tutorial" and "Oral Anatomy and Physiology" (carving parameters such as crown length, crown width, crown thickness, mesial and distal diameter bisectors of the labial surface, proximal long axis, neck height marking line, crown length marking line, etc.), a standard three-dimensional shape of 28 permanent teeth that can be scaled proportionally was designed. Step 2: Construction of standard dentition morphology (1) Constructing the parabolic shape of the dental arch The vertical distance between the line connecting the most prominent labial points of the left and right central incisors and the line connecting the most prominent distal points of the last teeth on both sides of the dentition is called the dentition length. The distance between the distal buccal cusps of the bilateral second permanent molars is called the dentition width. The intercuspal distance of the canines represents the anterior dentition width, the interfossa distance of the first premolars represents the middle dentition width, and the interfossa distance of the first molars represents the posterior dentition width. In Chinese people, the maxillary permanent dentition is approximately 55 mm wide and 50 mm long; the mandibular permanent dentition is approximately 52 mm wide and 41 mm long.

[0014] Based on the length and width of the dentition, a parabolic shape of the dental arch is constructed using a β function to fit the normal occlusal arch morphology. Specifically, the contact point of the central incisor, the cusps of the bilateral canines, and the distobuccal cusps of the bilateral second molars are selected; the curve is determined by these five points. The general form of the β function can be simplified to: Y = D[1 - (2X / D)] 2 ] e Where: D is the width of the second permanent molar, i.e., the distance between the distobuccal cusps of the two second permanent molars. w is the depth of the second permanent molar, i.e., the distance from the incisor contact point to the line connecting the distobuccal cusps of the two second permanent molars. e is calculated based on the position of the canines, minimizing and equalizing the distance from the curve to the cusps of the two canines.

[0015] (2) Tooth arrangement Once the parabolic shape of the dental arch is determined, refer to Chapter 7 of "Prosthodontics" for complete dentures for missing teeth. The specific method for tooth alignment restoration involves constructing a standard dentition morphology based on the standard crowns obtained in step 1.

[0016] Step 3: Obtaining Patient Anatomical Information The patient wears a facebow (such as the Artex facebow system), assumes a resting jaw position, and the dentist inserts the external auditory canal support bulb into both external auditory canals, slowly applying pressure. The patient is instructed to signal the dentist when they feel slight pressure. The screws between the facebow and the bow body are then tightened to prevent lateral movement. At this point, the front of the facebow is parallel to the line connecting the pupils on both sides, and the side is parallel to the ipsilateral nasal-tragus line (the midpoint of the nasal ala to the midpoint of the tragus, the midpoint of the nasal ala to the upper point of the tragus, and the lower point of the nasal ala to the lower point of the tragus are all approximately parallel to the jaw plane and can be used as landmark lines for locating the jaw plane), maintaining consistent height on both sides. The patient bites down on the optical resin occlusal plate, and a CBCT scan is taken. This obtains information about the patient's jawbone, dentition, and (occlusal) plane. The occlusal plate needs to be visualized on the CBCT or have visible markers to allow for the extraction of the patient's (occlusal) plane information on the CBCT.

[0017] Step 4: Personalized Tooth Arch Recognition The method for identifying the patient's dental arch and establishing a personalized dentition is as follows: Based on the standard length and width of the dental arch in Chinese people, a rectangular coordinate system is established with the dental arch width as the X-axis, the perpendicular line from the midpoint of the dental arch width to the X-axis as the Y-axis, and the midpoint of the crown width as the origin. In this coordinate system, the coordinates A(x1,0) and B(x2,0) and the midpoint coordinates C(0,y3) can be obtained based on the dental arch width. A quadratic equation is then solved based on these three coordinates: Maxillary lateral: y = -0.066x² + 50, medial: y = -0.09x² + 42.9; Mandibular lateral: y = -0.061x² + 41, medial: y = -0.082x² + 35.3. The length and width of the patient's dental arch are obtained from CBCT images, and these are substituted into the equation to obtain the dental arch morphology.

[0018] Step 5: Determine the future crown position in the edentulous area. The specific steps are as follows: (1) Determine the patient's (occlusal) plane To determine the occlusal plane, when a patient lacks reference teeth such as the maxillary central incisors, bilateral first molars, or bilateral second molars, or when all dentition is missing, a facebow can be used. The patient wears the facebow and undergoes CBCT imaging. The facebow's occlusal plate needs to be made of radiopaque material or have radiopaque markers to determine its occlusal plane position (the occlusal plane is the plane where the occlusal plate is located). Secondly, when the patient has the maxillary central incisors and bilateral first molars, an imaginary plane is formed by the mesial incisal angle of the maxillary central incisors to the mesial buccal apex of the bilateral first molars. This plane is parallel to the nasolabial line and essentially bisects the intermaxillary distance (i.e., the distance between the upper and lower alveolar ridges when in centric occlusion). In literature reports, some have also used the mesial lingual apex or distal buccal apex of the bilateral second molars as a location point to define the occlusal plane. (2) Matching digital standard dentition with the patient's dentition morphology The matching method is as follows: a phase correlation matching algorithm is used for coarse matching, and then least squares and phase correlation matching are used to correct the coarsely matched corresponding point pairs in the sequence image window. The correlation coefficient is calculated and compared, and the magnitude of the correlation coefficient is used as an indicator to measure whether the corresponding point pair is correct. The matching result with the largest correlation coefficient is selected as the final result. Experiments verify that this method can correct the coarsely matched corresponding point pairs and improve the matching accuracy.

[0019] The aforementioned least squares matching algorithm is a typical algorithm among gray-scale matching algorithms. It solves for geometric distortion parameters and radiometric distortion parameters in the image by minimizing the covariance, and uses the minimum covariance as the condition for iteration to ultimately minimize the sum of squared errors in the image.

[0020] The aforementioned phase correlation algorithm first performs scale transformation on the original image to obtain a scale space representation sequence of the image at multiple scales, and then extracts the main contour to obtain feature vectors. Then, it finds the extreme points of the difference of Gaussian pyramid by comparing each pixel with its neighboring points to complete the preliminary detection of key points. (3) Determine the future crown position in the edentulous area After the digital standard dentition is initially fitted to the patient's dentition, the approximate location of the future crown in the edentulous area is determined. Then, by combining the Andrews six criteria (molar relationship, crown angle, axial tilt, crown inclination, and crown torque) and the definition of contact and contact position in "Oral Anatomy and Physiology": two adjacent teeth are in close contact by their proximal surface convexity, and the point of contact is called the contact point; the proximal surface convexity of the anterior and posterior teeth is at the incisal 1 / 3 and (occlusal) 1 / 3, respectively; the mesiodistal contact area of ​​the first and second premolars and the mesiodistal contact area of ​​the first molar are both at the occlusal 1 / 3 on the buccal side; the distal contact area of ​​the first molar and the proximal contact areas of the remaining teeth are hidden in the middle 1 / 3 of the mesiodistal margin, etc., boundary conditions are set, and the final position of the future crown is determined by the anti-tooth collision and gap detection functions designed in the computer. Step 6: Obtain the central axis of the crown, i.e., the ideal axis position of the future implant. Following the restorative implant principle, once the future crown position is determined, the software automatically identifies the edges of each cross-section of the crown and automatically calculates the center point of the image. The center point of each layer can be displayed in three-dimensional space, and the straight line closest to these points is calculated using the least squares method; this line is the axis of the crown. Based on the concept of the long axis of the tooth, it is assumed that the crown and implant axes should be the same straight line; that is, the extended axis of the crown is the center line of the implant's long axis, thus determining the implant position.

[0021] Step 7: Reasonable inspection of mechanical anti-collision Referring to "Oral and Maxillofacial Surgery", the following aspects should be considered in the implant design for implant-supported prosthodontic restoration: 1. To prevent nerve damage, the bone thickness at the base of the implant should be greater than 1-2 mm from the upper edge of the mandibular nerve canal wall and the upper edge of the mental foramen; 2. The thickness of the buccal and lingual bone plates in the implantation area should exceed the implant diameter by at least 2 mm, that is, at least 1.5 mm of bone plate thickness on the buccal side and at least 0.5 mm of bone plate thickness on the lingual side; 3. The optimal distance between the implant and the adjacent natural tooth should be greater than 1.5 mm, the distance between the axes of the two implants should be greater than 6-8 mm, and the distance between the jaw and gingiva should be greater than 6 mm.

[0022] The system performs online checks on the alignment of the tooth roots and alveolar bone after tooth placement, ensuring the implants are properly positioned within the alveolar bone without bone cracking or fenestration. If a tooth root protrudes from the jawbone and is parallel to the jawbone, software commands can be executed to move the entire root until it is contained within the jawbone.

[0023] Step 8: Manual review and confirmation function.

[0024] After completing the implant placement design using the steps outlined in this embodiment, the clinician needs to review the final placement. If it meets the implant placement requirements, it will be adopted. If it does not meet the requirements, such as bone cracking or bone fenestration, the overall axis needs to be manually adjusted to ensure that the implant is contained within the jawbone.

[0025] Example 2 Based on Example 1, the difference in this example is that in step 2, the Bonwill-Hawley dental arch morphology diagram is used to construct the parabolic shape of the dental arch. Specifically, the sum of the widths of the six anterior teeth not only determines the radius and arc length of the anterior arc, but the isosceles triangle constructed by it also determines the direction of the line segments on both sides of the posterior part. Finally, the line segments representing the positions of the second and third molars should turn slightly towards the midline. First, the x and y coordinate axes are drawn, and then points A and C are drawn according to AC = (total width of the two anterior teeth + 3mm) / 2. Since HC = HA = AC, ∠CHA = 60°. With H as the center (coordinate (0, -AC)) and AC as the radius, an arc with a central angle range of 30° to 150° is drawn. Then, with point A as the center and 57.15 mm as the radius, an arc with a central angle range of 180° to 360° is drawn. The curve is the basic morphology diagram of the individual dental arch (Bonwill-Hawley diagram).

[0026] Example 3 Based on Example 1, the difference in this example is that in step 4, the method for establishing a personalized dental arch is as follows: the inner and outer boundaries of the alveolar bone are found by comparing gray values ​​(brightness and darkness), and the dental arch shape is formed by repeatedly identifying and fitting selected points using matrix or least squares method.

[0027] Example 4 Based on Example 1, the difference in this example is that in step 4, the method for establishing a personalized dentition is as follows: based on CBCT image data information, piecewise linear transformation and median filtering are used for image enhancement and noise reduction, and maximum density projection is used to select the tooth boundary region. Example 5 Based on Example 1, the difference in this example is that, in step 4, the method for establishing a personalized dental arch is: a panoramic image synthesis algorithm that suppresses non-interest tissues, image enhancement processing based on filtering, and improvement of the contrast of the panoramic image.

[0028] Example 6 Based on Example 1, the difference in this example is that in step 5, the matching method used when matching the morphology of the digitized standard dentition with the patient's dentition is as follows: The feature point matching of the image is completed by combining the SIFT feature description operator and the nearest neighbor distance ratio algorithm. This involves dividing the pixels within a certain range around the feature point into blocks, calculating the gradient histogram within the block interval, generating a feature vector describing each feature point, and then using the nearest neighbor distance ratio algorithm to find matching point pairs.

[0029] The present invention has been described in detail with reference to the foregoing embodiments. Those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for designing implant placement in edentulous areas using artificial intelligence technology, characterized in that, Includes the following steps: Step 1: Create a standard dental crown; Step 2: Constructing the standard dentition morphology: Based on the length and width of the dentition, the β function is used to fit the normal dental arch morphology or the Bonwill-Hawley dental arch morphology diagram is used to construct the parabolic shape of the dental arch. Based on the standard crowns obtained in step 1, the teeth are arranged to construct the standard dentition morphology. Step 3: Obtain patient anatomical information and identify personalized dentition: Based on the standard length and width of the dental arch in Chinese people, a rectangular coordinate system is established with the width of the dental arch as the X-axis, the perpendicular line from the midpoint of the dental arch width to the X-axis as the Y-axis, and the midpoint of the crown width as the origin. In this coordinate system, the coordinates A(x1,0) and B(x2,0) and the midpoint coordinates C(0,y3) can be obtained from the dental arch width. Based on these three coordinates, a quadratic equation is solved: Maxillary lateral: y = -0.066x² + 50, medial: y = -0.09x² + 42.9; Mandibular lateral: y = -0.061x² + 41, medial: y = -0.082x² + 35.

3. The length and width of the patient's dental arch are obtained from CBCT images, and the dental arch morphology is obtained by substituting them into the equation. Step 4: Determine the patient's occlusal plane, and then match the digital standard dentition with the patient's dentition morphology to determine the future crown position in the edentulous area; Step 5: Obtain the central axis of the crown, i.e., the ideal axis position for the future implant: Once the future crown position is determined, the edges of each cross-section of the crown are identified, and the center point of the image is automatically calculated. The center point of each layer can be displayed in three-dimensional space. The straight line closest to these points is calculated using the least squares method, which is the axis of the crown. The crown axis is extended further to become the center line of the implant's long axis, thus determining the implant position.

2. The method for designing implant placement in edentulous areas using artificial intelligence technology according to claim 1, characterized in that, In step 2, the method of fitting the normal dental arch morphology with the β function to construct the parabolic shape of the dental arch is as follows: the contact point of the central incisor, the cusps of the bilateral canines, and the distobuccal cusps of the bilateral second molars are selected; the curve is determined by five points: the contact point of the central incisor, the cusps of the bilateral canines, and the distobuccal cusps of the bilateral second permanent molars. The form of the β function is: Y = D[1 - (2X / W)] 2 ] e Where: D is the width of the second permanent molar, which is the distance between the distal buccal cusps of the two second permanent molars; W is the depth of the second permanent molar, which is the distance from the incisor contact point to the line connecting the distal buccal cusps of the two second permanent molars; e is obtained by solving for the position of the canines, so that the distance from the curve to the cusps of the two canines is the shortest and equal.

3. The method for designing implant placement in edentulous areas using artificial intelligence technology according to claim 1, characterized in that, The method for constructing the parabolic shape of the dental arch using the Bonwill-Hawley dental arch morphology diagram in step 2 is as follows: First, draw the x and y coordinate axes. Then, according to AC = (total width of the two anterior teeth + 3mm) / 2, draw points A and C. With point H(0, -AC) as the center and AC as the radius, draw an arc with a central angle ranging from 30° to 150°. Then, with point A as the center and 57.15 mm as the radius, draw an arc with a central angle ranging from 180° to 360°. The resulting curve is the basic morphology diagram of the individual dental arch.

4. The method for designing implant placement in edentulous areas using artificial intelligence technology according to claim 1, characterized in that, In step 2, the length of the dentition is the vertical distance between the line connecting the most prominent points of the labial side of the left and right central incisors and the line connecting the most prominent points of the distal side of the last tooth on both sides of the dentition, and the width of the dentition is the distance between the distal buccal apex points of the second permanent molars on both sides.

5. The method for designing implant placement in edentulous areas using artificial intelligence technology according to claim 1, characterized in that, The method for obtaining the patient's anatomical information in step 3 is as follows: The patient wears a facebow and assumes the occlusal position. The physician places the external auditory canal support ball into both external auditory canals and slowly applies pressure. The patient is instructed to signal the physician when they feel slight pressure. The screws between the facebow and the bow body are tightened to prevent it from moving left or right. At this time, the front part of the facebow is parallel to the line connecting the pupils on both sides, and the side part is parallel to the line connecting the nasal ala and tragus on the same side, and the height of both sides is kept consistent. The patient bites down on the optical resin occlusal plate, and a CBCT scan is taken to obtain information on the patient's jawbone, dentition, and occlusal plane.

6. The method for designing implant placement in edentulous areas using artificial intelligence technology according to claim 1, characterized in that, The method for matching the digital standard dentition with the patient's dentition morphology in step 4 is as follows: a phase correlation matching algorithm is used for coarse matching, and then least squares and phase correlation matching are used to correct the corresponding point pairs of the coarse matching under the sequence image window. The correlation coefficient is calculated and compared, and the magnitude of the correlation coefficient is used as an indicator to measure whether the corresponding matching is correct. The matching result with the largest correlation coefficient is selected as the final result.