Abstract
The purpose of this study was to clarify the distribution of the inferior alveolar artery (IAA) and its dental branches in the mandibular canal and surrounding tissues in both dentulous and edentulous mandibles using a Micro-CT system.
Twenty-six sides of 18 mandibles from Japanese cadavers were examined. Contrast medium was injected into the maxillary artery of the examined specimens to obtain the Micro-CT and 3-D reconstruction images. Maximum vertical length and horizontal breadth of the mandibular canal were measured to determine the position of IAA in the canal. The angle of the dental branches against IAA and the inside diameter of IAA were also examined.
The vertical position of IAA in the molar area was higher in the edentulous than that in the dentulous mandible. There was, however, no significant difference in the horizontal position. The retromolar ramus, in which the dental branches were distributed at the retromolar region, was usually observed to run toward the buccal just after separating from IAA. The inside diameter of IAA was smaller in the edentulous than that in the dentulous mandible.
These results suggest that positional change of IAA in the mandibular canal and decrease of inside diameter may be caused by absorption of alveolar bone following tooth loss and subsequently morphological change of the mandibular canal. However, the running direction of the retromolar ramus did not change.
