Comparison And Correlation of Radiographic And Non Radiographic Methods of mixed Dentition Space Analysis With The Formulation of Linear Regression Equation In Children of Mandi District, Himachal Pradesh

Introduction: Predicting the size of unerupted teeth during the mixed dentition period is a critical factor in managing the developing occlusion. The Nance radiographic method, Moyers mixed dentition space analysis and Johnston Tanaka method are among the most commonly used in clinical practice for detecting tooth sizearch length discrepancies. In view of reported secular trends, racial, and sex differences in tooth sizes, the purposes of this study were to compare and correlate the radiographic and non radiographic mixed dentition space analysis in children of Mandi district, Himachal Pradesh and to formulate a regression equation using the best variable predictors. Method: Odontometric data were collected from 52 male and 48 female subjects of Himachal descent, aging from 8-11 years who had fully erupted mandibular permanent incisors and first molar and unerupted permanent canines and premolars. The measurements of mesiodistal crown widths were made with Vernier scale digital calipers. The odontometric values obtained were then subjected to statistical and linear regression analysis. Results: All tooth groups showed no significant differences (P>0.001) between mesiodistal widths of male and female subjects. Very high correlation was found between the two non radiographic methods i.e. Moyer’s and Johnston –Tanaka method with their r values of 0.990. Correlation of Nance radiographic method with Moyer’s and Johnston Tanaka method was fair showing r values of 0.661 and 0.673 respectively. Conclusion: Estimation of tooth width in early mixed dentition is best made by means of radiographs of the yet unerupted teeth. The non radiographic methods as given by Moyers and Johnston Tanaka give reasonable approximation for prediction width of crown width when it is impossible to obtain satisfactory image.