Impacted Mandibular Third Molar Prevalence and Patterns in a Nigerian Teaching Hospital: A 5-Year Retrospective Study

Mandibular third molars are the most commonly impacted teeth. The prevalence and pattern of impacted mandibular third molars in patients presenting to the Obafemi Awolowo University Teaching Hospitals Complex, a tertiary hospital in south-western Nigeria, are largely unknown. This retrospective study examined 469 patient records, extracting socio-demographic and clinical information for analysis. It also determined the prevalence and pattern of impacted mandibular third molars from January 2015 to December 2019. The positioning of impacted teeth was assessed via periapical radiographs utilizing Winter’s classification. Data were subjected to analysis with IBM SPSS version 20, utilizing frequencies, percentages, and likelihood ratios, with statistical significance set at p < 0.05. The prevalence of impacted mandibular third molars within the study cohort was 2.51%, with a higher incidence observed in the 21–29 age group (p < 0.001). Mesioangular impaction was the most prevalent, with pericoronitis being the primary reason for extraction, and periodontal pockets being the most common associated pathology.