无牙颌患者自然头位的研究

目的：了解无牙颌患者相对于有牙个体自然头位（natural head posture,NHP)的差异，以及义齿戴入即刻和戴用后短期NHP的变化。方法；分别选取20例无牙颌患者和22名有牙对照组个体，采用视线标记的头颅定位侧位片记录NHP。无牙颌患者拍摄义齿戴前、义齿戴入即刻和戴用3个月后3张X线片。有对照组拍摄一张X线片。选取6项角度测量值评价NHP，3项角度测量值和2项线距测量值评价下颌骨的位置。比较无牙颌患者义齿戴前与牙对照组上述指标的差异，以及义齿戴入即刻和戴用3个月后的变化。下颌骨垂向明显上移（P＜0．05）。义齿戴入即刻，颈椎曲度显著增高（P＜0．05）。义齿戴用3个月后，颅颈角显著减小（P＜0．05）。结论：无牙颌患者在义齿戴入即刻和戴入后短期，自然头位出现一定程度的改变；与不戴义齿的头位相比较，调整至一个新的更接近正常的平衡状态。

The sutdy of natural head posture in edentulous patients before and after oral rehabilitation

Objective To study the natural head posture (NHP) of edentulous patients compared with dentate people and to understand NHP shift immediately inserting complete dentures and three months after denture wearing. Methods The NHPs of twenty edentoulous patients and twenty two dentate subjects were recorded with cephalometric technique. The NTPs of edentulous patients were exposed three times, before inserting, right after inserting and three months after inserting dentures. The NHPs of dentate subjects were recorded once as a controlled group. Six angles measured from the radiographs were evaluated for the NHP and three angles and two linear measures for the mandibular position.Results Compared with dentate subjects, the craniomandibular angles of the edentulous patients increased and the camber of the cervical columns decreased,but changes of the NHP were not significant The mandible showed a significant upward moving( P < 0 05) and an insignificant forward moving. At the time of denture insertion, the camber of the cervical columns significantly increased( P < 0 05). Three months after using the dentures, the craniomandibular angles of the patients obviously decreased. ( P < 0 05). Conclusion The shift of NHP after denture inserting does exist. The shifted NHP of the patients with dentures is a new balanced posture and closer to the normal position than the NHP of them without dentures