Abstract: Objective    To investigate and analyze the prevalence and risk factors of malocclusion in children at mixed and early permanent dentition period in Chengdu. Methods    Investigate the malocclusion of 2056 children at mixed and early permanent dentition period in Chengdu by questionnaires and clinical examination，and analyze the prevalence and possible risk factors of malocclusion. Results    The prevalence and mean of caries of children investigated in Chengdu was 59.78% and 2.33. The prevalence of malocclusion of children at mixed and early permanent dentition period was 64.64% and 71.01%.The risk factors of malocclusion were caries（OR = 3.805，95%CI：3.029 - 4.778，P < 0.001），genetic history（OR = 2.251，95%CI：1.219-4.156，P = 0.010），bad oral habits（OR = 18.794，95%CI：9.643-36.629，P < 0.001）and refined food（too-refined food：OR = 7.016，95%CI：4.557-10.802，P < 0.001；refined food：OR = 3.714，95%CI：2.587-5.333，P < 0.001）. Conclusion    The prevalence of caries and malocclusion of children at mixed and early permanent dentition period in Chengdu is still at the high level. The risk factors of malocclusion include caries，genetic history，bad oral habits and refined food. 

Key words: mixed dentition period, early permanent dentition period, children, malocclusion

摘要： 目的    调查研究成都地区混合牙列期及恒牙列初期儿童错牙合畸形的患病率，分析影响错牙合畸形发生的相关危险因素。方法    通过问卷调查及临床检查的方法，抽样调查5 ~ 13岁处于混合牙列期及恒牙列初期成都地区2056名儿童的错牙合畸形患病情况，统计错牙合畸形患病率并分析其可能的危险因素。结果    调查儿童患龋率为59.78%，龋均为2.33。混合牙列期儿童错牙合畸形患病率为64.64%，恒牙列初期错牙合畸形患病率为71.01%。错牙合畸形发生的危险因素包括龋病（OR = 3.805，95%CI：3.029 ~ 4.778，P < 0.001）、错牙合畸形遗传史（OR = 2.251，95%CI：1.219 ~ 4.156，P = 0.010）、口腔不良习惯（OR = 18.794，95%CI：9.643 ~ 36.629，P < 0.001）及食物精细（过于精细食物OR = 7.016，95%CI：4.557 ~ 10.802，P < 0.001；一般精细食物OR = 3.714，95%CI：2.587 ~ 5.333，P < 0.001）。结论    成都地区混合牙列期及恒牙列初期儿童患龋率及错牙合畸形患病率均处于较高水平；错牙合畸形发生的危险因素包括龋病、错牙合畸形遗传史、口腔不良习惯及食物过于精细。

关键词: 混合牙列期, 恒牙列初期, 儿童, 错牙合畸形