Abstract: Abstract: Objective To make a correlation analysis of crown widths between premolar,cuspid,and other teeth groups in malocclusion population.Methods Pre-treatment models of 382 patients (187 males,195 females,aged from 14 to 25 years) were selected from the records of the Orthodontic Department,Stomatology Hospital of Jiangsu Province.According to the Angle′s classification,the subjects were divided into 4 groups:Class I,Class Ⅱ division 1,Class Ⅱ division 2,and Class Ⅲ.The mesiodistal dimensions of teeth were measured using callipers (accurate to 0.02 mm).Then crown width correlation was analyzed and the prediction equation was set up.Results The correlation coefficients had significantly statistical difference.Equations predicting summation of mesiodistal crown-widths of upper and lower unerupted canine and premolars in male and female were established respectively.The male:U3U4U5=0.270X+3.504(r2=0.5821),L3L4L5=0.272X+2.390(r2=0.5977).The female:U3U4U5=0.221X+6.884(r2=0.4951),L3L4L5=0.230X+5.173(r2=0.5000) (X represents the summation of the mesiodistal crown widths of upper and lower central incisors and first molars).Conclusions The equations predicting summation established by this research were more precise than Moyers regression scheme,and were not influenced by the Angle′s classification.

Key words: Angle’s classification, crown width prediction, correlation analysis