Association Between Lower Third Molars Impaction and Mandibular Angular Fractures: A prospective Cohort Study in Major Hospitals in Sana’a City

Abstract

Background and objective: Mandibular angle fractures are among the most common facial injuries and are
often associated with impacted third molars (ITMs). While several studies have suggested a link between
impacted mandibular third molars and the likelihood of mandibular angle fractures, the nature and strength
of this relationship remain inconclusive, particularly in Yemen. Therefore, this study aimed to investigate the
relationship between impacted mandibular third molars and mandibular angle fractures in Yemeni patients
attending major hospitals in Sana’a City, Yemen.
Methods: A prospective case-control study included 52 patients with impacted mandibular third molars.
They were divided into two equal groups: Group A included patients with mandibular angle fractures who had
sustained trauma and were referred to the oral and maxillofacial surgery department of selected hospitals.
Group B included patients without mandibular angle fractures who had sustained trauma and were referred to
the oral and maxillofacial surgery departments of the selected hospitals. Data were collected through clinical
and radiographic examinations, orthopantomograms, cone beam computed tomography ( CBCT), and written
questionnaires. The condition of the mandibular third molars was assessed according to the Bell, Gregory, and
Winter classification systems. Data were analyzed using chi-square tests, proportional hazards, and logistic
regression to assess the association between impacted third molars and angle fractures using the SPSS
program (Version. 26).
Results: Impacted lower third molars were present in 50% of the fracture cases and 42.3% of the controls, with a calculated RR of 1.18, indicating a slight but non-significant increase in the fracture risk. Missing
third molars were significantly associated with mandibular angle fractures (OR = 2.4; p = 0.004), whereas
erupted third molars appeared to have a protective effect (OR = 0.4; p = 0.011). No statistically significant
differences were observed between the different impaction classifications.
Conclusion: The results indicated that impacted lower third molars may slightly increase the risk of mandibular
angle fractures; however, this association was not statistically significant. In contrast, the absence of third
molars was associated with an increased fracture risk, as erupted molars provide structural support. In addition,
the limitations of the current study restrict the clinical application of such findings.