Quantification of teeth is of clinical importance for various computer assisted procedures such as dental implant, orthodontic planning, face, jaw and cosmetic surgeries. In this regard, segmentation is a major step. In this paper, we propose a method for segmentation of teeth in volumetric computed tomography (CT) data using panoramic re-sampling of the dataset in the coronal view and variational level set. The proposed method consists of five steps as follows: first, we extract a mask in a CT images using Otsu thresholding. Second, the teeth are segmented from other bony tissues by utilizing anatomical knowledge of teeth in the jaws. Third, the proposed method is followed by estimating the arc of the upper and lower jaws and panoramic re-sampling of the dataset. Separation of upper and lower jaws and initial segmentation of teeth are performed by employing the horizontal and vertical projections of the panoramic dataset, respectively. Based the above mentioned procedures an initial mask for each tooth is obtained. Finally, we utilize the initial mask of teeth and apply a Variational level set to refine initial teeth boundaries to final contours. The proposed algorithm was evaluated in the presence of 30 multi-slice CT datasets including 3,600 images. Experimental results reveal the effectiveness of the proposed method. In the proposed algorithm, the variational level set technique was utilized to trace the contour of the teeth. In view of the fact that, this technique is based on the characteristic of the overall region of the teeth image, it is possible to extract a very smooth and accurate tooth contour using this technique. In the presence of the available datasets, the proposed technique was successful in teeth segmentation compared to previous techniques.

Segmentation of teeth in CT volumetric dataset by panoramic projection and variational level set

Virtual occlusion in planning orthognathic surgical procedures.

Rapid Automatic Segmentation and Visualization of Teeth in CT-Scan Data

Dental biomaterials Dental implantology Dental radiography Electronic health records Implant research Rapid prototyping and dental applications Software support in clinical dentistry Software support in oral surgery Tissue engineering of teeth Virtual reality dental simulator.

Dental Computing and Applications: Advanced Techniques for Clinical Dentistry

System and method for automatic construction of orthodontic reference objects, such as the occlusal plane, arch form, and the local occlusal plane for a patient's teeth are disclosed. In accordance with an exemplary embodiment, a computer-implemented system and method for automatic construction of orthodontic reference objects comprises receiving three dimensional data for the teeth, setting an initial direction for a normal of the occlusal plane, determining tips for selected teeth, calculating a plane that matches the determined tip, and determining a new normal for the calculated plane.

System and method for automatic construction of orthodontic reference objects

Purpose To develop an easy-to-use, dentition planning method which is based on three-dimensional (3D) computer planning technology to replace conventional plaster-cast occlusion planning techniques.

Dentition planning with image-based occlusion analysis

An interactive software module has been developed which can be used for 3D alignment of a graphical model of upper and lower dental arches. Using this module, special tools have been implemented for functional planning of dentition which can be compared to the CT image sequence of patients to create personalized results. The alignment procedure is made under the condition of centric occlusion, i.e., after bringing occlusal surfaces of mandibular and opposing maxillary arches into identical 3D position. The occlusal surfaces are approximated by triangles and used to build up the dentition curves around them. The presented procedure for dentition planning together with the implant positioning may serve as a flexible tool for image-guided prosthesis design. The involvement of function-related principles in dentition planning adds new optimization strategies in computer-assisted insertion of implants.

Ferenc Pongrácz

Papers

Dentition planning with image-based occlusion analysis

Dentition planning for image-guided implantology