Determination of anatomical position of inferior alveolar nerve canal in relation to buccal cortical bone in patients with different mandibular skeletal relationships.

Introduction: The anatomic relationship between the mandibular canal, cortices and molar apices are critical in preventing nerve damage during various mandibular orthognathic surgeries. The purpose of this study was to determine the relationship between the position of the inferior alveolar canal and the buccal cortex. Analyzing the variation of the nerve position in patient with different mandibular skeletal relationships like prognathic and retrognathic mandible is critical for better prognosis of the surgery.

Methods: A total of 45 patients including 15 in class I, class II & class III skeletal mandibular relationships were included in this study. The measurement of buccal and lingual cortical plate thickness was done using CBCT.

Results: For the distance from the outer buccal cortex to the IAN canal at the level of the mandibular first, second and third molar regions, the mean distance was observed to be 4.605±0.98, 738±1.313, 4.994±1.584 respectively. The distance from the outer lingual cortex to IAN canal at the level of the mandibular first, second and third molars were observed to be 1.848±0.399, 1.550±0.307 and 1.370±0.395 respectively.

Conclusion: The mean buccal cortical thickness was least in the class III group at mandibular first, second, and third molar regions. The lingual cortical thickness was least in the class II group, suggesting that the cut maybe given at the second molar region where the buccal cortical thickness is highest in order to prevent IAN injury. Hence, suggesting that precise osteotomy cuts may be customized to each patient using CBCT as an analyzing tool.