Anatomical and topographic classification of the mandibular canal with bone atrophy caused by the loss of the masticatory teeth

Abstract

The loss of teeth leads to disorders of the maxillofacial system, primarily causing bone atrophy, which by its destructive and morphological changes, affects the topographic features of the mandibular canal(s), causing a vector of restrictions in planning the rehabilitation of such patients. To clarify these features, we conducted a study with the analysis of 2,457 3D digital images and a detailed morphometric study of 136 CT scans with the creation of 3D reconstruction models of the mandibular canal(s). The identified anatomical variants and their systematization led to the aim to develop an informative anatomical and topographic classification of the mandibular canal with bone atrophy caused by the loss of the masticatory teeth for implementation in daily clinical practice. In the body of the lower jaw, with a preserved dentition, the most common manifestations of the variant anatomy are bifid branches of the mandibular canal and, less often – trifid modifications that have a clear X-ray visualization. Also, additional independent canals with separate exit foramina on the outer surface of the chin area are diagnosed. However, their visualization is lost in the jaw with bone atrophy, leaving a reference point for the main trunk of the canal. The results obtained confirm the expediency of creating an anatomical and topographic classification as an effective diagnostic tool to solve the problems of reconstructive, minimally invasive surgery presented in this paper.