Evaluation of the Impaction Pattern of the Third Molar Teeth in an Iranian Population

Statement of Problem: Impaction of the third molar teeth is common. Due to the probable complications resulting from tooth impaction and the effects of the impaction pattern on treatment plan, the evaluation of this pattern is important. This study aims at evaluation of the impaction pattern of the third molar teeth and its relation with the depth of impaction.Methods and Material: In this descriptive study, panoramic radiographs of 409 patients aged 20-40 years old who referred to Dental Clinic of Guilan University in a two-year period were chosen. The depth of impaction was evaluated according to the relationship between the Ccementoenamel junction Junction (CEJ) of the third molar tooth with the alveolar crest. Winter classification was used for detection of the angulations of the impacted teeth. Pearson Chi square test was applied for data analysis. There were 44.7% males and 55.3% females in this study. Evaluation of the impaction depth showed that, the most frequent impaction level was level C in in the maxilla, and it was level B in the mandible it was level B. In the maxilla, 47.5% and in the mandible, 41.2% of the impacted teeth were found in the male patients. The maximum and minimum frequency of different kinds of impaction angulations was vertical (67%) and horizontal (0%) in the maxilla. In the mandible, it was mesioangular (57.3%), distoangular (1.1%), respectively. In the evaluation of different impaction angulations based on the impaction depth, most of the vertical and mesoangular patterns of the impacted teeth were accompanied with level C and level B, respectively. There was no difference between female and male patients for frequency of the impacted teeth in the maxilla and mandible. Distribution of the angular pattern of impaction was different in the maxilla and mandible. There was no significant difference between the frequency of impaction angulations in different impaction levels.