正畸美学区的CBCT测量分析

Measurement of region of interest for orthodontics using cone beam computed tomography

目的：探究正畸美学区，包括面下1／3前牙区牙槽骨、切牙位置以及唇部软组织在不同矢状面型、年龄及性别之间的差异性。方法2012年6月至2013年5月间在山东大学口腔医院进行治疗的60例12～50岁汉族人，根据不同矢状骨面型、性别和年龄分组。根据头影测量 ANB 的角度分为3组：骨性Ⅰ类（1°＜ANB≤5°，23例，38．3％），骨性Ⅱ类（ANB ＞5°，18例，30％），骨性Ⅲ类（ANB ≤1°，19例，31．7％）；根据性别分组：女性41例（68．3％），男性19例（31．7％）；根据年龄分组：青少年组12～19岁22例（36．7％），青年组20～29岁20例（33．3％），中年组30～50岁18例（30％）。分别进行锥形束 CT（CBCT）测量分析。骨性分组以及年龄分组采用方差检验和多个独立样本检验（Kruskal-Wallis 检验），性别组间用独立样本 t 检验。结果①不同矢状骨面型之间，骨性Ⅱ类患者前牙区牙槽骨及切牙过度萌出，骨性Ⅲ类患者下唇缘点的唇厚度最小；②不同性别之间，骨和软组织的各项测量值男性均大于女性；③随年龄增长，切牙区牙槽骨的高度、切牙的位置以及唇部软组织变化明显，而牙槽骨的宽度和骨皮质厚度基本稳定。结论正畸美学区在不同的矢状面型、性别和年龄间呈现一定的变化规律，有利于指导临床决策。

Objective To investigate the region of interest （ROI）for orthodontics,including the dimension of anterior alveolar bone,labio-lingual position （LLP）of central incisors relative to the bone,and soft tissue （ST）between differ-ent horizontal face types,genders and age.Methods A total of 60 subjects of Han nationality aged 12 to 50 years were divided into different groups according to horizontal face type,gender and age.According to ANB：skeletal classⅠ（n =23,38.3%,1°〈ANB≤5°）,skeletal class Ⅱ（n =18,30%,ANB〉5°）,skeletal class Ⅲ（n =19,31.7%, ANB≤1°）.According to gender,the subjects included 41 female （68.3%）and 19 male （31.7%）.According to age,the subjects were divided into adolescent group （n =22,36.7%,12 to 19 years old）,young group （n =20, 33.3%,20 to 29 years old）,and middle age group （n =18,30%,30 to 50 years old）.The ROI of orthodontics was measured on sagittal sections using cone-beam CT （CBCT）.For statistical evaluation,one-way ANOVA and Kruskal-Wallis tests were performed.Results ① Class II group had higher anterior alveolar bone and overeruption of the inci-sors.② The ST and the dimension of anterior jaw of males predominated over those of females.③ The change of the height,LLP and ST was significant while the width and cortical bone thickness （CBT）basically remained stable with age.Conclusion There are some regular changes of ROI among different horizontal face types,genders and age, which should be considered in orthodontic treatment strategies.