6～12岁女童头影测量中颅面形态遗传作用的纵向分析

目的探讨遗传和环境因素在生长发育过程中对颅面形态的影响,以及各种口腔正畸治疗的可行性和所受的遗传限制,以提高正畸治疗质量,尤其是混合牙列期儿童的早期矫治水平。方法测量89对双生子女童的头颅侧位片;采用混合纵向观察法,最终得到有效双生子对数183对（其中同卵110对,异卵73对）;利用双生子法纵向统计分析颅面形态的遗传和环境作用。结果上下颌的前后位置关系（ANB、NAP）、颅面深度（L1、L2、L3）、面后部高度（H2、H6、SGo）受环境因素影响（P〈0.05）,而面前部高度（H1、H3、H4、H5、NMe）、面后部高度（H2、H7）受遗传因素影响（P〈0.05）。结论早期矫治能够改变上下颌的前后位置关系及颅面深度,且以面下部深度变化最明显;早期矫治能改变面后部高度,但有遗传阻力,其中面前部高度具有高度遗传阻力,最难被改变。

Longitudinal genetic effects on craniofacial morphology in cephalograms of female twins from six to twelve years old

Objective To study the relative effects of genes and environment on the craniofacial morphology during the growth and development stage, discuss the possibilities and genetic limitations of the various orthodontic treatment so as to enhance the treatment level, especially for early treatment started in the mixed dentitions. Methods The sample used in this study consisted of lateral cephalograms of 89 pairs of female twins in Beijing. With a mixed longitudinal method, 183 pairs （MZ 110, DZ 73） of effective twins were obtained. The genetic and environmental effects were analyzed on craniofacial hard tissue morphology of female twins from six to twelve years old by twin statistical methods. Results Statistical analysis revealed that environmental factors had significant （P 〈 0.05） effects on anterior-posterior position between lower and upper jaws （ANB and NAP）, eraniofacial depth （LI, L2 and L3）, and posterior height of face （H2, H6 and SGo）, whilst genetic effects showed significant impact on anterior （H1, H3, H4, H5, and NMe）and posterior（H2 and H7） face height （P 〈 0.05）. Conclusions Early orthodontic treatment may be effective to change anterior-posterior position between lower and upper jaws, craniofacial depth （especially the lower face depth）, and posterior height of face. The relatively high inherited proportions of craniofacial height should be recognized, and this might be a resistance to the treatment, especially the front height of face.