分块的LeFortI型截骨术术后截骨块、牙髓血供变化的实验研究

EXPERIMENTAL STUDY OF BLOOD SUPPLY CHANGES OF MAXILLARY AND TOOTH PULPFOLLOWINGSEGMENTALLE FORTIOSTEOTOMY

给１２只成年猕猴施行标准的ＬｅＦｏｒｔＩ型截骨术的同时，行右上前颌分块截骨术，分成单牙骨块和双牙骨块，井结扎两侧腭降动脉。另外用４只成年猕猴作为正常对照，不施行任何手术。术后采用放射性核素９９ｍＴｃ－ＭＤＰ对术后截骨块、牙髓血供作动态性研究。术后２ｈ截骨块、牙髓的血供分别比正常减少７２％～８２％、７４％～９３％，术后３个月比正常增加了５５％～１１４％、６％～３３％，６个月后截骨块血供恢复正常，与正常比无统计学差异。比较左、右两侧上颌截骨块和牙髓的血供无显著性差异，但６个月后牙髓的血供有下降趋势，是否可视为牙髓开始发生或已经发生病理组织学改变的一个信号仍有待于作更进一步研究。

Segmental Le Fort I Osteotomywas performed in 12 adults rhesus monkeys.The descending palatine Vessels txlere ligated in all experimental animals.ntravenous injection of 99mTc-MDP was used to measure the blood flow of the maxillarv and tooth pulp at variousintervals during the period of 6 months after operation. The results showed that the blood flowto the osteotomized maxillary segment and tooth pulp decreased 72%～83% and 74%～ 93%respectively 2 hours after operation, increased 55%～114% and 6%～33% respectively 3months after operation,and gradually returned to normal 6 months after operation. There wereno statistically sigriificant differences in the blood flow changes between the lett and tne rigntosteotoinized maxillary seginents in all the experimental groups. The results of our study indi-cate that the collateral cirulation within the maxillary and its enveioping soft tissue,and thenumerous vascuiar anastomoses in the anterlor and plsterior of the maxillary,are sumcient tomaintain the blood circuiation with the technique used in this investigatlon and also permit va-rious modifications.