Incidence of distal caries in mandibular second molars due to impacted third molars - a clinical and radiographic study

ABSTRACT

Occurrence of distal caries in lower second molars has been associated with impacted mandibu-lar third molars especially mesioangular impactions. Caries detection and restoration can be difficult and if it progresses, root canal treatment or extraction of the second molar may be necessary. The aim of this retrospective study was to evaluate the incidence of caries on distal aspect of mandibular second molars in patients referred for corresponding third molar assessment and to identify its association with angular position and depth of the impacted mandibular third molars based on the classification of Pell and Gregory. Two hundred impacted mandibular third molars were assessed in a total of one hundred and sixty seven patients presenting to the Department of Oral and Maxillofacial Surgery, Islamic International Dental College and Hospital from April 2011 to July 2012. These patients had age range between 18-57 [mean age of 37years] According to this study, 42.5% cases show caries on distal aspect of mandibular second molars. Incidence of caries with mesioangular impacted third molars was 51%. Majority of these mesioangular cases were level B and Class I as per Pell and Gregory Classification. Distal caries found in association with horizontal impactions was 29.10%, vertical impactions 15.2% and distoangular impactions 4.7%. No caries was found in relation to transverse impactions. It was concluded that distal caries in second molars is common, especially in cases of mesioangular mandibular third molar impactions and prophylactic removal of these impacted teeth may be considered appropriate. If such a third molar is left in situ, close monitoring is necessary