Can the Position of the Impacted Third Molars Be an Early Risk Indicator of Pathological Conditions? A Retrospective Cone-Beam Computed Tomography Study.

Objectives: The aim of this retrospective study was to evaluate the prevalence of pathologies associated with impacted third molars in relation to tooth position on cone-beam computed tomography images.

Material and methods: In 348 cone-beam computed tomography images, the position of 640 impacted third molars (mesiodistal angulation, buccolingual inclination, impaction depth, and contact point localization) and the presence of pathologies (distal caries, external root resorption, marginal bone loss, and pathological follicular space) were evaluated. The data were analysed statistically with a significance level set at P < 0.05.

Results: Distal caries was mostly detected in relation to Class A (20.4%) and contact point at (12.5%) and above (10.5%) the cementoenamel junction (CEJ) (P = 0.000; P < 0.05). External root resorption and marginal bone loss were more common in mesioangular angulation (52.3% and 80.1%, respectively), Class C (53% and 73.8%, respectively), and contact point below the CEJ (53.2% and 73.3%, respectively) (P = 0.000; P < 0.05). Lingual inclination was identified as a new risk factor for associated pathologies (P < 0.05). Pathological follicular space was significantly more likely to occur in those with inverted angulation (100%) and absence of contact (31.5%) (P = 0.000 and P = 0.010, respectively; P < 0.05).

Conclusions: Pathologies arising in second molars in relation to impacted third molars are significantly associated with the three-dimensional position of impacted third molars, and watchful monitoring or prophylactic removal of impacted third molars should be considered, taking into account the relevant risk parameters for the related pathologies.