Evaluation of the reliability of regression equations developed for the Turkish community in the size estimation of permanent canine and premolar teeth in mixed dentition

The aim of our study is to evaluate the suitability of the regression equations developed by Arslan et al., Uysal et al., Sağlam Aydınatay et al. for the Turkish population and to provide a more realistic evaluation opportunity for orthodontists in treatment planning by finding a new regression equation suitable for our population with the measurements we made in our patients in case of incompatibility. The material of our study consisted of orthodontic cast models of 265 patients (133 females and 132 males) between the ages of 10.4 and 26 years who applied to the Department of Orthodontics at the Faculty of Dentistry of Ankara Yıldırım Beyazıt University. The measurements were made with a precision of 0.01 mm using a Hammacher digital caliper and the measurements were recorded including two digits after the comma. In our study, upper right canine tooth (tooth 13), upper right first premolar tooth (tooth 14), upper right second premolar tooth (tooth 15), upper right first molar tooth (tooth 16), upper left canine (tooth 23), upper left first premolar (tooth 24), upper left second premolar (tooth 25), upper left first molar (tooth 26), lower right central incisor (tooth 31), lower right lateral incisor (tooth 32), lower left canine (tooth 33), lower left first premolar (tooth 34), lower left second premolar (tooth 35), lower left central incisor (tooth 41), The mesiodistal dimensions of the lower left lateral incisor (tooth 42), lower right canine (tooth 43), lower right first premolar (tooth 44), lower right second premolar (tooth 45) were measured. The data obtained in this study were analyzed using SPSS 21 package program. Normality tests of the data were examined with the Kolmogorov-Smirnov Test. Linear Regression Analysis was used to analyze the data to make measurement predictions. A significance level of 0.05 was used. In our study, there was a significant difference between the actual dimensions measured on plaster models and the regression values developed by Arslan et al, Uysal et al, Sağlam Aydınatay et al. The estimated values of the regression equations developed by Arslan et al., Uysal et al. and Sağlam Aydınatay et al. underestimated the mesiodistal width of unerupted canines and premolars, and therefore a new regression equation was developed using the data from our sample group.