S. DechkunakornJ. ChaiwatP. SawaengkitMahidol University2018-06-142018-06-141990-05-01The Journal of the Dental Association of Thailand. Vol.40, No.3 (1990), 94-99004599172-s2.0-0025431092https://repository.li.mahidol.ac.th/handle/20.500.14594/16048The objective of this study is to investigate the accuracy of Moyers' probability chart in predicting canine and premolar sizes from the sum of lower incisors in a group of Thai subjects. The fifty models of orthodontic patient, Faculty of dentistry, Mahidol University with no loss of tooth material mesio-distally, fully erupted permanent teeth, no mesial or distal restoration and normal tooth morphology were selected. The results of this study show that the under-estimation less than or equal to 2 mm. is 32 casts on upper (64%) and 28 casts on lower (56%) and the over estimation greater than 2 mm. is 16 casts on upper (32%) and 18 casts on lower (36%). In comparison of 14 models which have the same value of sum of lower incisors, there is a significant (alpha = 0.05) difference between the combined canine and premolar size of this study and Moyers' probability chart.Mahidol UniversityMedicineArticleSCOPUS