Radiographic analysis of the trajectory of the fourth canal in first maxillary molar

The purpose of this study was to evaluate, by radiographic exam, thetrajectory of the mesiopalatal canal in maxillary first molars, aiming at assessing the importance of the radiographic analysis in the treatment of these teeth; due to great incidence of two canals in the mesiovestibular root. Sixty-five extracted maxillary first molars were donated by students of PUC/PR and used in this study. Periapical radiographs of the teeth were taken at 20 degrees in the disto-eccentric incidence and positioning #10 K-type files into the canals. The analysis aimed at distributing the sample according to the classification of root canal system proposed by Weine [7]. The obtained result was: 47.7% (31) – type I; 21.5% (14)–type II; 12.3% (08) – type III and 18.5% (12) – calcified. It can be concluded that a careful analysis of the mesiovestibular root is important to guarantee a good prognostic of the treatment.