Assessment of the relationship between impacted mandibular third molar and inferior alveolar canal and the related factors using Cone-Beam Computed Tomography (CBCT)

There is a risk of nerve injury during the extraction of the impacted third molars, in cases with proximity of the inferior alveolar nerve and this tooth. The aim of this study was to evaluate the effect of different various factors on the degree of vulnerability using CBCT (Cone Beam Computed Tomography) imaging technique. CBCT images of 191 patients referred for the exact assessment of the relationship between the mandibular canal and impacted mandibular third molars were selected. The position of these anatomical structures was evaluated at their contact point. The possible effect of gender, impaction form of the third molars, anatomical relationship between the third molars and the mandibular canal and the age differences were studied. Data were analyzed using Chi-square and Student’s t-test. There was a close relationship between the mandibular canal and impacted third molars in 81.7% of the patients. The contacts were shown to be significantly higher in females than males (P=0.01) and in the cases with the lingually position of the third molar and the mandibular canal (P<0.001). However, the age and impaction form of the teeth did not have a significant influence (P>0.05). The risk of nerve damage or exposure is increased in females and lingual position of the mandibular canal to the third molar in cases with higher proximity between these 2 structures in panoramic radiographs using CBCT images. Therefore, the surgeon must pay enough attention in these cases of third molar extraction.