上顎骨 前方部 部分 骨折斷術後 齒髓 神經纖維 再生에 關한 組織學的 硏究

Histological study on the reinnervation of pulpal nerve fiber following anterior maxillary segmental ostetomy

The segmental osteotomy is one of the commonly used surgical procedure for the treatment of various dentofacial deformities involving the maxilla. Common complication after osteotomy was stabilization, inflamation, relapse, paresthesia, necrotic change of fragment and pulpal degeneration. The condition of the pulp after segmental maxillary osteotomics in human has only been studied in a few clinical investigations. Many investiga+ors believe that subsequent reinnervation and vascularization is accomplished, however, few clinical studies have been directed at evaluating this phenomonen. Conflicting results have also been reported of tooth response after segmental osteotomy procedures in the maxilla. Studies in patients show the incidence of non-responsive teeth to electrical stimulation varying from 6 to 43%. Animal studies have also reported wide variation in the effect on the pulp, varying from nil to marked cellular changes by 13e11(1969), Poswillo(1972), Ohzeki & Takahashi(1980) and Nanda(1982). The purpose of the present study was to determine the degeneration and reinnervation of pulpal nerve fiber after the segmental maxillary anterior osteotomy. The reinnervation of anterior maxillary teeth (]enervated by segmental osteotomy has been investigated in clogs by using light and electron microscopy, The extracted teeth from segmental fragment were cut off at right angle to the long axis of the tooth at the apical 1 mm portion on 1, 2, 4, 8, 24 weeks after osteotomy. The following observation were made : 1. One week after osteotomy, most pulpal axon showed sign of degeneration and decreased the number about 74% axons compare with control group. 2. Two weeks after osteotomy, only alomost intact two myelinated fibers and few degenerated unmyelinated fibers were presented. 3. Four weeks after osteotomy, all axons were disappeared. 4. Eight weeks after osteotomy, a myelinated and unmyelinated axon were presented. 5. Twenty four weeks after osteotomy, numerous myelinated and unmyelinated axons were presented. The total axons were about 33% of control group. The ratio of unmyelinate axon was about 45%.