Prediction of lower permanent canine and premolars width by correlation methods.

The aim of this study was to determine linear regression equations to estimate the widths of unerupted lower permanent canines and premolars using measurements obtained from 45 degrees oblique teleradiographs. The sample consisted of 30 white Caucasian patients orthodontically treated at the Faculty of Dentistry, Universidade Federal do Rio de Janeiro. The records for each patient included a 45 degrees oblique teleradiograph (left side) in the mixed dentition period and a dental cast of the permanent dentition. Pearson's test was applied between each lower canine, first and second premolars measured on the radiograph, and the sum of their actual widths measured on the dental cast. The strongest correlation occurred for the first premolars for one side (.82) and both sides (.84). One linear regression equation was determined to estimate the widths of un-erupted lower canine and premolars of both sides from a single measurement of the first premolar.