가토 하악골 신장시 신연 방법에 따른 하악 과두의 조직학적 연구

Abstract

The purpose of this study was to investigate the histologic change of the mandibular condyle according to the various methods of mandibular lengthening. The osteotomy was performed on the left mandibular body, then unilateral distraction device was placed. Before lengthening of mandible a 5-day-latency period was allowed. The mandible was lengthened 0.5mm once a day for 6days(Group 1), 0.5mm twice a day for 3days(Group 2), 0.5mm once a day for 10 days(Group 3), 0.5mm twice a day for 5 days. Then 14-day- consolidation period was allowed. After consolidation, rabbits were sacrificed and microscopic and immunohistochemical examination of the mandibular condyle was performed. The result of this study were as follows: 1. There was no degenerative change of craniomandibular joint in all groups. 2. Histologic findings ; In distraction side, it showed thickened hypertrophic cartilage zone, enhanced endochondranous ossification and increased osteoblastic activity in 3, 4. In non distraction side, there was no considerable change, except the increased osteoclastic activities in Group 3, 4. 3. Immunohistochemical findings ; Tenascin immunoreactivity was observed in bone marrow mesenchymal cells in distraction side in Group 4, this is pointed that chondrocyte was more increased in Group 4. Connexin immunoreactivity was no remarkable change in all groups. Osteocalcin expression was observed in distraction side in Group 2, this is pointed that bone formations more increased. Nitric oxide synthase 2 immunoreactivity was observed in distraction side in Group 2, this is pointed that stress and inflammation is related. It was suggested that as the distraction amount and rhythm was more increased, hypertrophic cartilage zone was more thickened and endochondranous ossification was more cleared. However, there were no degenerative changes.