Inferior alveolar nerve dissection/repositioning during SSRO in hemimandibular hyperplasia: cases report and...

Inferior alveolar nerve (IAN) dissection and repositioning is critical for preventing iatrogenic IAN injury during combined mandibular border resection and sagittal split ramus osteotomy (SSRO) in patients with severe hemimandibular hyperplasia (HH). Traditional IAN repositioning includes two-stage and concurrent one-stage procedures. This study introduces a modified one-stage technique and compares the respective advantages and disadvantages of these three surgical protocols.

Four patients with HH were enrolled and treated with three different surgical protocols: one two-stage procedure, one conventional one-stage procedure, and two modified one-stage procedures. The modified technique features a vertical osteotomy placed 5 mm anterior to the mental foramen to protect the anterior loop of the IAN.

All patients achieved satisfactory facial symmetry and aesthetic improvement postoperatively. Neurosensory assessment at 6-month follow-up confirmed complete recovery of lower lip sensation without persistent numbness. Compared with the two-stage and conventional one-stage approaches, the modified technique effectively preserved the IAN anterior loop, simplified surgical procedures, and minimized bony defects by maintaining buccal cortical bone integrity.

The modified one-stage approach is a simplified and effective technique that provides reliable neuroprotection for the anterior loop of the IAN while minimizing bony defects during SSRO in HH patients. Given the limited sample size of this case series, further large-sample and long-term studies are required to fully validate tits efficacy, long-term stability, and complication profile.