Surgical Management of Mandibular Intraosseous Schwannomas
Intraosseous schwannomas of the mandible are rare tumors that usually arise from peripheral nerve sheaths of the main trunk or branches of the inferior alveolar nerve (IAN).
A systematic review of the English literature through PubMed was conducted from 1945 to 2016. Forty-nine patients of mandibular intraosseous schwannomas were identified. The most common location of the tumor was the posterior mandible (61.2%). There were 28 patients in whom the tumor involved the IAN (57.1%). The most commonly performed procedures included enucleation through a mucoperiosteal flap and a bone window (73%), curettage (10%), segmental mandibulectomy (10%), and sagittal split ramus osteotomy (6%). The recurrence rate was 6%: all 3 recurrent patients occurred in the posterior area. The authors report a 72-year-old female with a schwannoma of the IAN which was removed through a sagittal split of the mandible, although there was a bony defect of the external cortex after biopsy of the lesion. The nerve was reconstructed with a sural nerve graft.
Due to the slow growing nature and encapsulation of schwannomas, surgical resection seems the best treatment with optimal functional outcomes and low recurrence rate even with a minimally invasive approach. Sagittal split ramus osteotomy and segmental mandibulectomy are reserved to large or posterior lesions to aid with radical resection or improve exposure and reconstruction.