镍钛记忆合金牵引装置前牵上颌骨成骨对颅面骨长度的影响

Effect of maxillary advancement on craniofacial bone by trans-sutural distraction with internal nickel titanium memory alloy distractors

目的研究经腭横缝前牵上颌骨对颅面骨、下颌骨长度和咬合关系的影响。方法 12周龄杂种犬10只,随机分为空白对照组4只,实验组6只。实验组于腭横缝前后打孔,安置特制内置式镍钛记忆合金牵引装置,利用其产生的弹力前推上颌骨。向前持续弹性前推4周,观察牵引前后颅面骨、下颌骨长度和咬合关系的变化情况。结果实验犬上颌逐渐前突,咬合关系呈现Ⅱ类错颌。后期逐渐恢复尖窝相对的咬合关系。颅面骨、下颌骨长度较对照犬明显增加。结论本牵引装置可有效地延长上颌骨的长度,在上颌骨延长的同时,下颌骨的长度同时得到了延长,同时最终得到相对正常的咬合关系。

Objective To investigate the effect of maxillary advancement on craniofacial bone by trans-sutural distraction with internal nickel titanium memory alloy distraetors. Methods Ten mongrel dogs aged 12 weeks were randomly divided into sutural distraction osteogenesis （SDO） group （6 dogs ）, normal control group （4 dogs ）. In SDO group, distractors was placed in the palatine bone across the transverse palatine suture. Sham operation was performed on the dogs in the control group. Changes in maxillofacial bone length, mandible length and occlusion were observed during distraction period. Results The animals in SDO group showed a progressively maxillary advancement. The occlusal relationship turned into deep overjet （Class Ⅱ malocclusion）. There was gradual recovery of relatively normal occlusal relationship in the later stage. The dogs in the control group showed no significant occlusion relationship change. The maxillofacial bone and mandible length of the SDO dogs increased significantly compared with the control dogs. Conclusion The maxilla of the dogs could be advanced successfully by trans-palatine sutural distraction with the newly designed internal distractor and the length of the mandible was extended at the same time, thus relatively normal colossal relationshio was obtained.