Correlation Between Lower Third Molar Impaction Types and Mandibular Angle and Condylar Fractures: A Retrospective Study

Abstract

The purpose of this study was to investigate and determine the relations between mandibular third molar (M3) impaction types and mandibular angle and condylar fractures. A retrospective study was conducted in patients with mandibular angle and condylar fractures referred to the Oral and Maxillofacial Surgery Department of the Shahid Kamyab Hospital (Mashhad, Iran) from 2013 to 2018. Data sources were patients' hospital documents and panoramic radiographs. Predictor variables were the presence and position of impacted M3s. ThePell-Gregory classification was used to identify the horizontal and vertical positions of impaction. The impaction angulation was determined using the Schiller classification. Outcome variables were the presence of angle and condylar fractures. Data were analyzed using SPSS 16 (IBM Corp, Armonk, NY) and χ2 and Fisher exact tests. The study sample consisted of 117 patients (63.2% with condylar fractures, 30.8% with angle fractures, and 6% with concomitant fractures of the condyle and angle). Most patients (88.9%) with angle fracture had impacted M3s; however, impacted M3s were absent in 59.5% of condylar fracture cases. Mesioangular and vertical positions were the most prevalent impaction angulation types in patients with mandibular angle fracture. Classes II and B were the most frequent horizontal and vertical impaction types, respectively, according to the Pell-Gregory classification. There was a statistically significant difference between fracture site and the presence or absence of impacted M3s (P<.001). Moreover, a significant relation was observed between horizontal impaction type and fracture site in patients with impacted M3s (P=.001). The presence of impacted M3s increased the risk of angle fractures and simultaneously decreased the risk of condylar fractures. Fractures of the angle region were more commonly seen in patients with superficially impacted (vs deeply impacted) M3s.