Predicting the size of unerupted canines and premolars using primary maxillary first molar

Abstract

One of the most important aspects of interceptive orthodontic diagnosis and treatment planning is space analysis. To date all methods use the size of permanent teeth to predict the dimensions of unerupted teeth. The aim of this study was to predict the permanent teeth size using maxillary primary first molar. The size of primary maxillary first molars and permanent canines and premolars of 80 subjects was measured on their dental casts. Regression equations were determined between the size of primary maxillary first molars and permanent canines and premolars. The new regression equations for predicting permanent tooth size in the maxilla and mandible were, respectively, Y = 2.2X + 13 and Y = 2.4X + 9.5 among females and Y = 2.7X + 5.5 and Y = 2.4X + 9.5 among males. The results show that the primary maxillary first molar size can be used to predict the size of unerupted permanent teeth.