Patterns of mandibular third molar impaction and its relationship with distal caries in the adjacent mandibular second molars: A retrospective study.

Background: Impacted third molars can cause significant challenges for dental health. While many of these impacted teeth remain asymptomatic, they can lead to dental caries. Objective: To investigate the patterns of mandibular third molar impaction and its relationship with the occurrence of caries in the adjacent mandibular second molars. Materials and Methods: This study assessed the dental panoramic radiographs of 1591 participants who visited the Department of Oral and Maxillofacial Surgery at the Dental Teaching Hospital at Umm Al-Qura University between 2022 and 2024. The presence of distal caries in the adjacent mandibular second molars was assessed and compared across the different impaction patterns, considering both age and gender. Results: The results showed that 29.22 % of the patients had impacted mandibular third molars. The most common patterns of impacted mandibular third molar angulation were mesioangular in the females and horizontal in the males. The majority of these impacted third molars were level A and class I (as per the Pell and Gregory classification).One hundred and eighty-three (39.35 %) of the impacted mandibular third molars had associated carious lesions, with 89 showing distal caries in the adjacent mandibular second molar and 18 showing caries in the third molar itself. The carious lesions were most commonly found in cases of mesioangular, level A, and class I impaction patterns (p < 0.05). Conclusion: The findings of this study shed light to the high prevalence of carious lesions associated with impacted mandibular third molar, especially in cases of mesioangular, level A, and class I impaction patterns. These findings highlight the importance of careful monitoring of impacted third molars to prevent the development of caries in the adjacent teeth.