Development of a prediction equation for the mixed dentition in a Pakistani sample

Introduction: Regression equations are widely used for mixed dentition analysis. However, estimations from these equations can vary in different population groups. The aim of this study was to produce simple linear equations and tables for Pakistani children. Methods: Two hundred subjects of Pakistani descent who met our criteria (ages, 13-15 years; 100 boys, 100 girls) were selected from local schools. The mesiodistal widths of all mandibular permanent incisors, canines, and premolars were measured and analyzed by using paired t tests. The results were also compared with predicted values from the Moyers and the Tanaka and Johnston methods. Correlation and linear regression analyses were performed between the predicted and actual tooth sizes for Pakistani children, and standard regression equations were developed. Results: No significant differences were observed for measured canine and premolar antimeres and sex. Significant and high positive correlations were found between the mandibular incisors and the combined mesiodistal widths of the canines and premolars for the maxillary (r = 0.65; P <0.001) and mandibular (r = 0.59; P <0.001) segments. Conclusions: The equations and charts commonly used for North American children (75th percentile) did not accurately predict for our sample. The regression equations and tables developed in this study can be used for orthodontic treatment planning for children in Pakistan.