Application of cone-beam X-ray CT in dento-maxillofacial region

Abstract

3-dimensional imaging system using a 2-dimensional detector and cone-beam x-ray was developed for dental field. This method reconstructs an isotropic 3-dimensional image from a set of projection images acquired during one rotation scan (9.6 Sec scan time). This system uses high-speed high-precision CCD television camera and Image Intensifier (4.0, 7.0 and 9.0 inches) as a detector and has new techniques to improve image quality and reduce x-ray dose. This system can reconstruct 5l2x5l2x5l2-voxel (130 milion-voxel) image with 0.20–0.35 mm/voxel resolution. Conventional X-ray images such as dental X-ray, panoramic, and cephalogram were reconstructed from volumetric data by image processing software. The application of this new method in dental field was examined with volunteers. From the results, the detailed structures of dento-maxillofacial region (from foramen mentale to TMJ) could be visualized in the 3D images. Bucco-labial extension of periapical lesion, related position of mandibular canal and dental implants, and position of impacted teeth were easy to detect more than conventional x-ray image. Accurate 3-dimensional image of dental arch was also reproduced from serial axial image. This system is widely applicable in dental field and can be used to derive clinically useful information about 3-dimensional maxillofacial structure, tooth position and bone quality.