偏[牙合]伴反殆患者治疗前后牙弓形态变化的研究

目的：分析与比较偏颌伴反牙合]畸形矫治前后的牙弓形态变化。方法：选择偏颌伴反牙合]畸形病例9例，制取矫治前后石膏模型。将模型平行于基准平面扫描到计算机。应用计算机测量软件测量上下颌尖牙、前磨牙和磨牙牙尖的纵横坐标值，分析牙弓矢向和横向的对称性、上下牙弓的协调性。采用SPSS11．0进行统计学分析。结果：矫治前上颌尖牙和第一前磨牙距腭中缝的距离偏向侧大于偏离侧（p〈0．05），下颌从尖牙到第二磨牙偏向侧距中线的距离小于偏离侧（p〈0．05）；上颌尖牙和第一前磨牙的牙弓宽度比率较矫治后小（p〈0．05），上颌第二前磨牙和第一磨牙的牙弓宽度比率矫治前后无统计学差异（P〉0．05）；上颌偏向侧和偏离侧牙齿的矢向位置变化无统计学差异（p〉0．05），下颌牙齿在矢状方向第一磨牙偏向侧大于偏离侧（p〈0．05）。结论：偏颌畸形患者上牙弓前部较下牙弓前部窄，矫治易先扩大上颌牙弓，使得矫治后上下牙弓宽度比例协调。

The analysis of arch form before and after the orthodontic treatment on patients with facial asymmetry

Objective： To study the characteristics of dental arches before and after the treatmentment in the patients with facial asymmetry. Method： 9 patients with Facial Asymmetry were selected as the study subjects. They are 6 girls and 3 boys, agea form 12-year to 17-year, who were made as control after orthodontic ／ treatment .Before and after the treatment , study models were cast. The occlusal surfaces of the models were scanned with a ruler in the field. Dental arch asymmetry, coordination between upper and lower dental arch were measured.by E-ruler soft ware. SPSS 11.0 was used in statistical analysis. Result： The distance from cuspid and the first bicuspid to the median palatal raphe in the side of crossbite was larger than that of contralateral side in maxilla. The distance from cuspid, bicuspids and the first molar to the midline in the side of crossbite was smaller than that of contralateral side in mandible （p〈0.05）. The dental arch width of cuspid and first premolar in maxilla was smaller than that of mandible （p〈0.05）.The dental arch length of molar in mandible in the side of crossbite was bigger than that of contralateral side in mandible （.p 〈0.05）. Conclusion： The width of upper anterior dental arch was smaller in facial asymmetry patients.The upper arch should be expanded to make coordination between upper and lower dental arch.