DISCRIMINANT-ANALYSIS IN TREATMENT EVALUATION OF ECTOPIC ERUPTION OF THE MAXILLARY FIRST PERMANENT MOLARS

The value of an analytical routine which could be used in the evaluati on of clinical studies was assessed. Stepwise discriminant analysis wi th stepwise selection/elimination was used to reduce the amount of dat a without losing information before further analyses with canonical di scriminant analysis. The purpose of canonical discriminant analysis wa s to reveal interactions between factors associated with the ectopic e ruption of the first permanent molars. Two canonical discriminant func tions were used to determine the accuracy of diagnosis and the effect of treatment. This information consisted of variables which were the m ost important (their ranks) and their single correlations (structure c oefficients) to the function itself. This information was interpreted clinically. The coefficients of the canonical discriminant functions c an be used for classification purposes. The use of a scatterplot inste ad of simple classification tables is suggested. The scatterplot was p articularly informative on how well the procedure discriminated betwee n groups. A table based on original data is included to allow the read er to test the validity of the findings on cases of his/her own. This multivariate strategy avoids spurious intercorrelations between two or more variables analysed as multiple single factors that has a high ri sk of erroneous conclusions.