安氏Ⅰ、Ⅱ、Ⅲ类错患者Bolton不调量的分析

目的　了解安氏错患者上下颌Bolton不调量的大小及发生率。方法　选择 4 39例安氏错患者的模型 ,分别测量上下颌 6个前牙 (左右恒尖牙之间 )及 1 2个恒牙 (左右第一恒磨牙之间 )的牙冠近远中宽度总和 ,根据Bolton指数正常值获取上颌Bolton不调量并作统计学分析。结果　 4 39例安氏Ⅰ、Ⅱ、Ⅲ类错患者中 ,前牙或全牙Bolton不调量绝对值大于或等于 1 5mm的错患者占该类患者的百分比分别为 1 4 0 2 %、9 4 9%、1 9 32 %或1 9 6 3%、1 5 33%、2 0 4 5 %。安氏Ⅰ类错患者前牙Bolton不调量以上前牙牙量减少、下前牙牙量增多为常见 ;安氏Ⅱ类、Ⅲ类错患者 ,前牙或全牙Bolton不调者上颌和下颌牙量偏多偏少 ,差异无显著性。结论　错患者Bolton不调不是引起错发生的主要原因

A Study of Bolton Tooth-size Discrepancies of Malocclusion Patients

OBJECTIVE: To analysis the sum and frequencies of Bolton tooth-size discrepancies Angle Class I, II, III malocclusion patients. METHODS: Measured each tooth crown mesial-distal size between the first molar of 439 dental plaster casts of malocclusion patients and obtained the sums of six anterior tooth-size and twelve tooth-size between the first molar of upper or lower and calculated the anterior and total tooth-size discrepancies by Bolton rate standards, then statistic analyses were done. RESULTS: Patients whose sums of anterior tooth-size discrepancy were pass 1.5 mm or less than -1.5 mm was 14.02% in Angle Class I malocclusion patients and 9.49% in Class II and 19.32% in Class III. Patients whose sums of total tooth-size discrepancy were pass 1.5 mm or less than -1.5 mm was 19.63% in Angle Class I malocclusion patients and 15.33% in Class II and 20.45% in Class III. The upper sum of anterior tooth-size of Class I malocclusion patients whose sums of anterior tooth-size discrepancies were pass 1.5 mm or less than -1.5 mm was always smaller than normal and the lower sum was always larger. The sums of anterior tooth-size discrepancy of Class I, II, III and total tooth-size discrepancy of Class I were always between 1.5 mm-2.5 mm or -2.5 mm(-)-1.5 mm. Patients whose sums of anterior tooth-size discrepancy were pass 3.5 mm or less than -3.5 mm was 2.34% in Class I malocclusion patients and 0 in class II and 0 in class III. Patients whose sums of total tooth-size discrepancy were pass 3.5 mm or less than -3.5 mm was 4.21% in Class I and 1.46% in Class II and 4.54% in Class III. CONCLUSION: Tooth-size discrepancy of malocclusion patients was not the general cause of malocclusion.