RESUMEN
To determine the accuracy of Pederson and Parant Scale for predicting the difficulty level of mandibular third molar extraction. Prospective cross-sectional, 6 months from January 2012 to June 2012. All consecutive patients who presented for the extraction of impacted third molars were included in the study. Orthopantomograms (OPGs) were advised and on these OPGs third molars were classified as easy, moderate or difficult according to standard Pederson scale. Similarly modified Parant scale was utilized to predict the difficulty of removal of third molars. Root pattern was also noted on the OPG. These parameters were then compared with peri-operative parameters like time taken for extraction and need for crown or root sectioning using Chi Square test. A p value of 0.05) while significant results were obtained in case of Parant Scale (p value<0.05). Statistically significant results were seen for root pattern and level of difficulty (p value<0.05). These scales failed to predict difficulty level of tooth removal accurately especially in cases of distoangular impactions. When combined with root pattern, the accuracy of prediction gets significantly better.