Background and Objective: Impacted mandibular third molars (M3Ms) should be treated promptly after diagnosis. This study aimed to determine the frequency of facial skeletal patterns among individuals with impacted M3Ms.
Methods: This retrospective descriptive-analytical study examined 312 lateral cephalometric radiographs and 312 panoramic radiographs from patients (130 men and 182 women; mean age, 23.51±2.73 years) with bilateral impacted M3Ms who attended the Department of Orthodontics at Babol Dental School during 2009-2021 SH (a 12-year period). Sagittal skeletal patterns were assessed using the ANB angle and Wits appraisal. Facial type was classified as mesofacial, brachyfacial, or dolichofacial using the facial axis angle. Mandibular length was measured and classified as short, normal, or long. The degree of M3M impaction was assessed radiographically using Winter's classification and the Pell and Gregory system.
Results: The dolichofacial growth pattern was the most common (39.7%), followed by brachyfacial (34.0%) and mesofacial (26.3%) patterns (P<0.05). Skeletal Class I was the most common (44.6%), followed by Class II (40.4%) and Class III (15.1%) (P<0.05). A long mandible was observed in 45.8% of participants, a short mandible in 30.8%, and a normal mandibular length in 23.4% (P<0.05). The most common M3M angulation was mesioangular (50.0%), followed by vertical (33.0%), horizontal (10.3%), and distoangular (6.7%) impactions (P<0.05). According to the Pell and Gregory classification, Class A and B impactions (45.8% each) were considerably more common than Class C impactions (8.3%). Regarding the ramus relationship, P1 (47.4%) and P2 (44.9%) were more common than P3 (7.7%) (P<0.05).
Conclusion: The dolichofacial pattern, a long mandible, and skeletal Class II were the most common characteristics among patients with impacted third molars. Mesioangular, Class A/B, and P1 were the most common impaction types. These findings highlight a possible association between facial skeletal morphology and third-molar impaction.