Location of the mandibular canal and the topography of its neurovascular structures.

The major complication in dental implant surgery is loss of sensation due to damage to the inferior alveolar nerve resulting from poor characterization of the location of the mandibular canal and the traveling course of the inferior alveolar nerve, artery, and vein therein. The purposes of this study were to determine the buccolingual location of the mandibular canal and to verify the topography of the inferior alveolar nerve, artery, and vein therein by three-dimensional reconstruction of these structures. Sixty-two mandible sides were used for this study. The buccolingual location of the mandibular canal was classified into 3 types: type 1 (70%), where the canal follows the lingual cortical plate at the mandibular ramus and body; type 2 (15%), where the canal follows the middle of the ramus behind the second molar and the lingual plate passing through the second and first molars; and type 3 (15%), where the canal follows the middle or the lingual one third of the mandible from the ramus to the body. Three-dimensional reconstruction of the mandibular canal revealed that the inferior alveolar vessel traveled above the inferior alveolar nerve in 8 cases (80%), with the inferior alveolar artery being lingual to the inferior alveolar vein, and in 2 cases (20%) where the inferior alveolar vessel was buccal to the nerve.