Purpose <p>The purpose of this study was to investigate the pattern of mandibular third molar impaction and its association with distal carious lesions of adjacent mandibular second molars (MSMs), as well as the occurrence of pericoronitis, in a Syrian population.</p> Methods <p>This cross-sectional study included 619 mandibular third molars (MTMs) from 365 Syrian patients. The pattern of impaction was assessed clinically and radiographically using Winter’s classification and Pell &amp; Gregory’s classification. The presence of distal caries on adjacent mandibular second molars and the occurrence of pericoronitis were recorded. Information on patient age and gender was also collected. Associations between impaction patterns and the presence of distal caries and pericoronitis were statistically analyzed, with <i>p</i> &lt; 0.05 considered significant.</p> Results <p>Among the 619 MTMs evaluated, 418 were in females and 201 in males. The most common age group was 21–25 years (40.8%). Mesioangular impaction was the most frequent type (55.3%), and Class A impaction was the most prevalent (64%). Pericoronitis occurred in 5.7% of cases and was significantly associated with age (<i>p</i> = 0.020), vertical impaction (<i>p</i> = 0.010), and Class A molars (<i>p</i> = 0.001). Distal caries was observed in 12.6% of cases, mainly in patients older than 26 years, with no significant gender difference (<i>p</i> = 0.791); the highest prevalence was found in Class A molars.</p> Conclusions <p>The anatomical position and angulation of impacted mandibular third molars significantly influence the risk of pericoronitis and distal caries. This finding suggests that prophylactic removal of these molars may help reduce associated complications.</p>