Objective: To observe the effects of an intror al tooth su pported distraction device on advancement mandible of goat.Methods :8 goats (7～9 months of age)were divided into 4 groups with 2 goats in each.After bilateral mandibular cortitomy between the second and third premolars ,selfproduced intraoral tooth-supported distraction devices were cemented on t o the second and third premolars.5 days after operation,the distraction devices began to be activated 0.25 mm every 12 hours to advance 8 mm of the anterior seg ment in 16 days.The animals were sacrificed on day 8,16,32,48 respectively since activation,then gross sample inspection,vascular contrast examination and radio graphic examination were performed.Results:Obvious bone le ngthening was o bserved between the second and third premolars with coverage of normal gingival tissue.Radiography showed that new bone gradually formed and matured.Th ere was no obvious side effect except that the anchoring teeth showed some titli ng.Vascular contrast examination showed that the lower alveolar arteries were co ntinuing.Conclusion:Tooth-supported DO device can effecti vely advance mandible of goat.%目的：观察自制的牙支抗骨延长装置进行羊下颌骨延长的实用性和有效性。方法：将8只7～9月龄羊分为4组，每组2只，在下颌第2 和第3前磨牙之间行骨皮质切开并造成青枝骨折后，将自制的颌骨延长装置粘固于牙齿上，术后5 d开始加力，每次0.25 mm ，每日2次。在开始加力后分别于第8、16、32、48天时将动物处死，标本进行大体观察、血管造影、X线检查。结果：大体标本显示，在下颌第2、第3前磨牙之间出现明显的骨延长区域，其表面由正常的牙龈组织覆盖。X线检查结果表明随着时间的延长，新骨不断形成并趋于成熟，加力结束后保持16 d的标本下颌骨连接性就已恢复，支抗基牙有所倾斜，周围其他组织未见明显不良反应。血管造影显示：在骨延长的各个阶段，下齿槽动脉通畅良好。结论：利用这种牙支抗的骨延长装置能够有效地进行下颌骨的延长。
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