Application of Moyer’s prediction table in a sample of Karachi population

Abstract

Introduction: Estimation of the mesio distal (MD) widths of unerupted teeth is essential in accurate diagnosis of mixed dentition orthodontic cases. Hence the purpose of this study was to evaluate the applicability of the Moyer’s method of prediction and to develop a new prediction method for Karachi based population.

Material and Methods: A study was conducted on a sample of 200 patients of Karachi population, age range being 13-25 years with complete permanent teeth except third molars. MD dimensions of permanent mandibular incisors, maxillary/mandibular canines and premolars were measured using digital calipers with a calibration accuracy of 0.01mm. Paired sample T- test was carried out to compare the measured tooth sizes with Moyer’s prediction table. Linear regression analysis was performed to correlate the relationship of lower incisors, maxillary and mandibular posterior segments with the established norms.

Results: Significant difference (p < 0.05) was found between the measured MD dimension of the buccal segment in maxillary arch in both males and females when compared with predicted width by Moyer’s at the 75^th percentile level. New linear regression equations were derived for both genders to allow accurate tooth size prediction for Karachi’s population. Correlation coefficients between the total MD widths of mandibular permanent incisors and that of maxillary/mandibular canines and premolars were found to be 0.712 and 0.539 in males and 0.880 and 0.875 in females.

Conclusions: Moyer’s prediction table is not an accurate method to estimate tooth dimensions in a Karachi based sample.