Mandibular Second Molars and Their Pathologies Related to the Position of the Mandibular Third Molar: A Radiographic Study.

Abstract

Objective: The aim of this study was to determine the prevalence of mandibular third molar malposition and its impact in relation to the lower second molar using panoramic radiography.

Methods and materials: This was a cross-sectional descriptive study of 353 panoramic images of patients who visited the Dental Clinic of the International University of Rabat. Panoramic images were analyzed in order to determine the number of second molar pathologies associated with the positions of third molars. The following radiographic lesions on the second molar were recorded: caries, root resorption and distal alveolysis. The Chi-square test was used to assess the association between different variables.

Results: Of these 353 radiographies, 169 were males, ie, 48%, and 184 were females, ie, 52%. The age range was from 18 to 63 years. The prevalence of the impacted position of the lower third molar was noted in 60%. Distal caries on the second mandibular molar was present in 47.5% of instances having an impacted third molar. Caries was present in 65.5% of wisdom teeth in a normal position and was also present in 79.6% of the impacted teeth. This difference was statistically significant with p = 0.01. The angulation of the third molar is a factor of caries of the second molar: 58.56% of them were carious. Of all the teeth in association with an angulation, 72.03% showed distal alveolysis in the second molar. In addition, root resorption was found in 20.4% of second molars linked to a wisdom tooth in all angulation occurrences.

Conclusion: It has been noted that among the pathologies seen on the mandibular second molar, distal alveolysis accounts for the majority of cases (58%), followed by caries (47.5%) and root resorption (13.3%). This study illustrated the importance of performing Orthopantomogram X-rays at each new consultation in patients over the age of 18.