36例下切牙先天缺失正畸治疗的临床体会

目的探讨下切牙先天缺失的矫治设计。方法以伴有下切牙先天缺失的36例错畸形患者为研究对象，对下切牙缺失的部位、数目、错类型、矫治方法进行分析，并对缺失1颗下中切牙、拔除上颌2颗第一前磨牙和下颌1颗非缺牙侧第一前磨牙的病例及缺失2颗下中切牙、拔除上颌2颗第一前磨牙的病例的Bolton指数分析进行统计学检验。结果36例患者正畸治疗后均取得了较好的疗效。两组拔牙病例之间的Bolton指数全牙比无统计学差异（P>0.05），而前牙比和前牙不调量有统计学差异（P<0.01）。结论先天缺1颗下中切牙上下颌均需拔牙者，在下颌非缺牙侧选择拔1颗前磨牙比拔1颗中切牙对Bolton指数影响要小

Clinical experience of orthodontic treatment on 36 cases with congenital lower incisor missing

OBJECTIVE: To explore the treatment plan in patients with congenital lower incisor missing. METHODS: Thirty-six patients with congenital lower incisor missing were included in the investigation. The missing location, missing quantity, malocclusion type and treatment method were analyzed. Bolton index of two groups were analyzed. The first group was congenital missing one lower incisor who treated by extracting two upper first premolars and one lower first premolar. The second group was congenital missing two lower incisors who treated by exacting two upper first premolars. RESULTS: The therapeutic effect of 36 cases were better. Overall ratio in two groups were 91.70% +/- 1.85% and 92.83% +/- 2.74%, anterior ratio were 81.69% +/- 2.12% and 85.46% +/- 2.39%, anterior tooth-size discrepancy were (2.16 +/- 0.64) mm and (4.27 +/- 1.14) mm. There were no significance difference on overall ratio in two groups (P > 0.05). There were significance difference in anterior ratio and anterior tooth-size discrepancy (P < 0.01). CONCLUSION: For patients with congenital missing one lower incisor who need extraction in upper and lower jaws, it is less affection on Bolton index that extracting one premolar at non-missing side than extracting one center incisor in mandible.