Assessment of Variables Affecting Caries on the Distal Surface of Second Molars in the Presence of an Impacted Third Molar

Aim: The most impacted teeth in the oral cavity are the third molars. Consequently, their presence within the bone often leads to various pathologies. The most common of these pathologies is distal caries. The aim of this study was to evaluate the relationship between impaction types of maxillary-mandibular third molars and distal caries of second molars using digital panoramic radiography. Materials and Methods: 750 maxillary and mandibular third molars were examined. Patient age and sex, groups of third molars according to Pell-Gregory and Winter classifications, posterior margin space of second molars, angle between occlusal planes of third and second molars and the distance between cementoenamel junction of third and second molars were recorded. Results: The prevalence of distal caries in the second molars was 42.0% in the upper jaw versus 47.4% in the lower jaw (p>0.05). According to the Pell-Gregory classification, the prevalence of distal caries in the second molar was higher in position A in the maxilla and in position B in the mandible (p<0.05). Based on Winter’s classification, the prevalence of distal caries in maxillary second molars was higher in vertical position, while in mandibular second molars, it was higher in mesioangular position (p<0,05). Conclusions: The risk of caries in second molars increases if the patient is older, when the vertical impaction level of third molar is A/B and at mesioangular/vertical position and mesial angulation is <40°. Clinicians and surgeons should pay attention to the position of the tooth in decision of early removal of third molars.