Oral panorama reconstruction method based on pre-segmentation and Bezier function / 生物医学工程学杂志

For patients with partial jaw defects, cysts and dental implants, doctors need to take panoramic X-ray films or manually draw dental arch lines to generate Panorama images in order to observe their complete dentition information during oral diagnosis. In order to solve the problems of additional burden for patients to take panoramic X-ray films and time-consuming issue for doctors to manually segment dental arch lines, this paper proposes an automatic panorama reconstruction method based on cone beam computerized tomography (CBCT). The V-network (VNet) is used to pre-segment the teeth and the background to generate the corresponding binary image, and then the Bezier curve is used to define the best dental arch curve to generate the oral panorama. In addition, this research also addressed the issues of mistakenly recognizing the teeth and jaws as dental arches, incomplete coverage of the dental arch area by the generated dental arch lines, and low robustness, providing intelligent methods for dental diagnosis and improve the work efficiency of doctors.

Digital 3D anatomical modeling of the mandible with full teeth / 解剖学报

Objective To study and establish a high quality digital 3D anatomical modeling of the mandible with full teeth.Methods A set of accurate digital models of standard anatomical specimens of mandibular teeth were obtained by laser scanning, and the 3D mandible model was reconstructed by CT scan data;then, a registration deformation method based on the geometry and image anatomical landmark was employed to do the registration of each tooth to the mandible model, and finally the tooth enamel , dentin, periodontal ligament were generated .Results A high quality digital 3D anatomical modeling of the mandible with full teeth was built , each tooth had detail crown and whole root , the distinction between the enamel , dentin, periodontal ligament , and any anatomical regions can be zoomed and rotately displayed . Conclusion The digital 3D anatomical modeling of the mandible with full teeth has realistic 3D imaging view and convenient teaching-learning function , and has tremendous apllication futures in the stomatology , maxillofacial and other medical departments .

THE APPLICATION OF RAPID PROTOTYPING IN THE ORTHOGNATHIC SURGERY / 解剖学报

Objective To construct a geometric skull model by using three-dimensional reconstruction, computer tomography scanning and rapid prototyping technology and evaluate its significance in treatment of complex oral and maxillofacial deformities. Methods A cranial and a goldenhar syndrome patient with complex oral and maxillofacial deformities bone received continuous volumetric scanning of skull and the data acquisition was done by an electron computed tomography, by which reconstruction was performed and the obtained images saved as STL files. Then the data were input into rapid prototyping machine to make three-dimensional geometric model. Direct measurement, designation and surgery simulation could be done on this three-dimensional model. Then the mandibular mirror physical model was manufactured using rapid prototyping according to the normal side. Results A computer-aided model according to CT data could represent the three-dimensional anatomic structures and their relationships precisely. The replica exhibited dimensional errors ranging 0.02 mm to 0.53 mm. Which provided strong basis for accurate understanding of disease status and reasonable surgical plans and helped improve the curative effect of surgery. Conclusion Rapid prototyping can help surgeons in many ways for therapy of the complex oral and maxillofacial deformities.