The Method Of Predicting The Width Of Unerupted Permanent Canines And Premolars For Qingdao Adolescent

Objective:The aims of this study were to develop a new,fast,and accurate method to predict unerupted canines and premolars mesio-distal tooth width and to determine which reference tooth or combination of reference teeth was the best predictor for canines and premolars in a Qingdao sample.Methods:The sample of 121 adolescent(48 male and 73 female ),aged from 15 to 18 years old,was measured using Moorree's method,with caliper accurate to 0.01 mm.The correlation coefficients were determined between the mesio-distal crown width of the permanent canines and premolars measured on the study models and the mesio-distal crown width of the other teeth.The specific linear regression equations for this population were calculated.Results:The results showed that the correlation coefficients between the sum of mesio-distal crown width of the permanent canines and premolars with the upper central incisor and the lower lateral incisor were high.In the male,the correlation between the maxillary permanent canines and premolars width with the upper central incisors width is more significant(r=0.600),then with the low lateral incisors width(r=0.547).The correlation between the mandible permanent canines and premolars width with the low lateral incisors width was more significant(r=0.659),then the upper central incisors width(r=0.635).In the female,the correlation between the maxillary permanent canines and premolars width with the upper central incisors width is more significant(r=0.557), then the low lateral incisors width(r=0.531),The correlation between the mandible permanent canines and premolars width with the upper central incisors,width was more significant(r=0552.),then the low lateral incisors width(r=0.523).Moyers' method was shown to be less reliable for females in this study.Tanaka—Johnston's method was shown to be more reliable for the upper side of both male and females.Conclusions:1,The linear regression equations for the unerupted canine and premolars were calculated including sex and arch. male maxilla Y=11.756+0.847X₁+0.635X₂ mandible Y=7.587+0.842X₁+1.175X₂ female maxilla Y=8.990+1.109X,+0.681X₂ mandible Y=9.236+0.847X₁+0.838X₂ Y represents the mesio-distal crown width of the unerupted canine and premolar X₁ represents the mesio-distal crown width of the upper central incisor, X₂ represents the mesio-distal crown width of the lower lateral incisor.2,Moyers' method and Tanaka—Johnston's method couldn't be used to predict the mesio-distal crown width of the permanent canines and premolars of the Qingdao sample. We can use the multiple linear regression equations which was calculated by the Qingdao sample to predict the mesio-distal crown width of the permanent canines and premolars.