Abstract
The pathology of mandibular nerve tissue underlying mandibular diseases was investigated on the basis of operative findings and histopathological observation of raected specimens to clinically determine the surgical limitations topreservation of the inferior alveolar nerve. The study was performed on 14 patients with cyst, 28 with tumor (19 benign and 9 malignant tumors) and 8 with osteomyelitis. Benign tumors consisted of 11 cystic type ameloblastomas, 5 solid type ameloblastomas, 2 myxofibromas and 1 cementoma. Osteomyelites consisted of 5 chronic osteomyelites of the lower jaw and 3 radiation osteomyelites.
In cystic diseases, though nerves were frequently compressed to the cystic wall, the inferior alveolar nerve was distinctly separated from the cyst without any histopathological abnormality of the nerve tissue, indicating that preservation of the inferior alveolar nerve was possible. In cystic type ameloblastomas, despite marked compression of the nerve tissue by severely developed tumors, the tumor and nerve tissue were clearly demarcated. Notwithstanding histopathological evidence of minor fibrosis around the epineurium, no abnormal pathology existed in the nerve tissue, indicating the possibilityof preservation. In solid type ameloblastomas, the nerve tissue was surrounded by the tumor with partial adhesion, which precluded preservation. In rnolignant tumors, severe fibrosis and hyalinization were histopathologically found to surround the nerve tissue. Preservation was impossible because of severe perineurial adhesion to the surrounding fibrous connective tissue, close contact with the tumor and tumor infiltration. In osteomyelites, macroscopical changes were demonstrable, and histopathological examination disclosed severe fibrosis around the nerve tissue and also severe hyalinization and degeneration along the perincurium. Preservation also proved to be impossible.
