Anatomic position of the lingual nerve in the mandibular third molar region as potential risk factors for nerve palsy.

Palsy of the lingual nerve (LN) during third molar extractions, ramus osteotomies, anesthetic injections, procedures of orthognathic, preprosthetic, and periodontal surgery are important complications reported with varying frequency. The purpose of this study is to present quantitative data describing the position and shape of the LN in the third molar area. In the course of dissection, the LN was noted, as well as the furcation pattern, position, course, and anatomic relations under 2.5X loupe magnification in 21 adult male human cadavers. The distance of the junction of the LN and the chorda tympani from the foramen ovale was measured as average 15.1 +/- 5.8mm. The 4 furcation patterns of the LN and the inferior alveolar nerve (IAN) were observed based on their relative positions. Bifurcation of them above the level of the mandibular notch (type I) was observed in 66.7% of the specimens. The horizontal distance of the LN from the lingual plate of the mandible was greater in this study than in previous studies. This study provided measurable objective criteria for the relationship of LN in the third molar region. The knowledge of the relationship between the LN and third molar region is useful for the surgeon in avoiding unexpected complications.