牙列拥挤的解除与上前牙唇倾度及突度变化的相关性研究

The evaluation of the relationship between the alleviation of crowding and the changes in maxillary incisor proclination and protrusion

目的:探讨解除牙列拥挤对上前牙唇倾度及突度的影响。方法:选择50例牙列拥挤的非拔牙正畸患者,通过术前术后模型及头影测量分析,通过直线相关与回归分析,比较牙列拥挤的解除量对上前牙唇倾度及突度的影响。结果:每毫米拥挤度的解除会增加上前牙唇倾度(U1-SN)0.8°及突度(U1-AP)0.4 mm,但是直线回归方程的拟合优度检验数值较低,需要进行包含更多参数的多元线性回归方程进一步分析。结论:每毫米拥挤度的解除会增加上前牙唇倾度0.8°及突度0.4 mm。结果表明唇倾度及突度的改善是由多方面因素决定的,不单纯与拥挤度的解除量相关。

Objective： To examine changes in maxillary incisor proclination and protrusion resulting from alleviation of crowding. Methods： Records of 50 patients with crowded dentition treated without extractions or interproximal enamel reduction in the maxillary arch were included. Pre-and post-treatment cephalograms and models were examined to determine changes in incisor proclination,protrusion and crowding. Results： For every millimeter of crowding alleviation,increases in incisor proclination（ U1-SN） and protrusion（ U1-AP） of 0. 8°and 0. 4 mm,respectively,we found,high variability was calculated for both linear variables that can be reduced by incorporating other variables by multilinear regression. Conclusion： For every millimeter of crowding alleviated,0. 8°of proclination and 0. 4 mm of protrusion are expected. Our results indicate that proclination is mulifactorial and cannot be explained solely by the amount of crowding alleviated during orthodontic treatment.