牙支抗牵张成骨中牙髓和牙周改变的实验研究

Dental pulp and periodontal tissues changes in distraction osteogenesis by tooth-attached intraoral distracter

目的 :研究使用牙支抗式牵张器行上颌骨牵张成骨术后牙髓和牙周的组织学改变。方法 :8只杂种犬为实验组 ,2只为对照组 ,建立上颌单侧牙槽突裂模型 ,带环固定口内牙支抗式牵张器 ,沿弓丝方向加力牵张成骨 ,行大体观察、X线摄片 ,并取支抗牙及移动牙的牙髓及牙周作组织学检查。结果 :移动牙牙髓受牵张力作用发生了轻度血管扩张、充血 ,随着固定时间的延长 ,受损牙髓逐渐得以恢复。移动牙牙周受力后有成骨 /破骨改变 ,未见炎症变化。支抗牙牙髓和牙周在整个牵张过程中均未见明显改变。结论 :牙支抗上颌骨牵张成骨术中移动牙牙髓可能发生了轻度的退行性变 ,但这种退行性变在适宜的牵张速率下是可逆的。牙周的改变与正畸牙受力后类似。

AIM:To observe the changes in dental pulp and periodontal tissues under the application of distraction osteogenesis using tooth-attached intraoral distracter.METHODS:8 dogs were experimental group, 2 were control group, the maxillary alveolar bone resection models were taken to manufacture intraoral tooth-attached distracter individually. After the alveolar bone resection, the tooth-bone complex transport disc osteotomy was performed ,at the same time the distracter and arch wire were fixed. The gradual distraction was started after 7 days latency period at the rate of 0.5 mm twice a day along the arch wire. Gross,X-ray and histology observation were performed at 0, 14, 28, 63 days after completion of distraction.RESULTS:The lightly hyperaemia and blood vessel expansion was seen in the dental pulp of the moving teeth, with time progression, the pulp could be gradually recovered its normal structure. The periodontal tissues performed hyperplasia in tension-side and absorption in stress-side. In the teeth used as anchorage , the pulp and periodontal tissues kept unchanged.CONCLUSION:In the process of distraction osteogenesis by tooth-attached intraoral distracter , moderate morphological changes in the dental pulp and periodontal tissue was seen, however, the changes may be reversible when a proper rate of distraction is used.