Double Hough Transform for Estimating the Position of the Mandibular Canal in Dental Radiographs

In this work, a multiple generalized anisotropic Hough transform (AGHT) is used to detect the mandibular canal in dental panoramic radiographs. The proposed method relies on a sequential application of the Hough transform that we call double Hough transform. The recognition of the mandibular canal is based on a double template matching compared with the clinical detection using the fact that the shape of the mandibular canal is usually the same and it is situated inside the mandibular bone. The experiments performed on real orthopantomographic images shown that the risk of false detection is significantly decreased, while the recognition is not affected by occlusion and by the presence of additional structures, e.g., teeth, projection errors.