CT画像による下顎管の位置と下顎枝矢状分割術後の下唇知覚障害との関係 Relations between location of the mandibular canal on CT images and sensory disturbances of the lower lip after sagittal splitting ramus osteotomy
Sagittal splitting ramus osteotomy is widely used to repair maxillofacial deformities. Postoperative sensory disturbances of the lower lip, however, are becoming an important clinical problem. The most important factor related to this complication is thought to be injury of the inferior alveolar nerve during osteotomy. This study was designed to obtain clinical evidence to support this hypothesis. We studied the relations between the developmentof postoperative sensory disturbances of the lower lip and topographic anatomy of the mandibular canal on preoperative standardized CT images in 30 patients (60 sides) with prognathism. The distance from the medial border of the lateral cortex of the mandibular ramus tothe mandibular canal was 2.49±1.24mm (mean±S. D.). The peak distribution (17sides) was within the range of equal to or greater than 3.0mm to less than 4.0mm. Postoperative sensory disturbances of the lower lip developed in 20 sides. Seven sides were within the peak distribution range of equal to or greater than 1.0mm to less than 2.0mm for thedistance between the lateral cortex and the mandibular canal. Our findings indicate that the greater the distance from the lateral cortex of the mandibular ramus to the mandibular canal, the lower is the frequency of sensory disturbances of the lower lip. Innovation andrefinement of surgical techniques to reduce injury to the mandibular canal during sagittalsplitting ramus osteotomy are considered to have substantially contributed to reducting postoperative sensory disturbances of the lower lip.
日本口腔外科学会雑誌 52(3), 167-171, 2006-03-20
Japanese Society of Oral and Maxillofacial Surgeons