Assessment of proximity of roots of mandibular third molar to the inferior alveolar canal in impacted teeth by radiovisiography

Aim: To assess the proximity of roots of mandibular third molar to the inferior alveolar canal in impacted teeth by radiovisiography” Background: Prior knowledge of the proximity of the roots of the mandibular third molars to the inferior alveolar nerve canal minimizes injury to the nerve. Previous studies have shown Intra Oral Periapical Radiograph (IOPA), Dental Panoramic Tomograph, and Cone Beam Computed Tomography (CBCT) as tool for assessment of risk of injury to the canal. The aim of our study was to assess proximity of roots of mandibular third molar to the inferior alveolar canal using radiovisiography (RVG). Methods: The total study sample enrolled 50 impacted mandibular third molars among 50 patients. Patients requiring surgical removal of impacted mandibular third molars are selected. Preoperative radiovisiographs was taken and the findings are correlated with findings during surgery. Study design: Descriptive interventional study. Result: Out of 50 patients 15(30%) were males and 35(70%) were females. All the nine radiographic signs were evaluated individually and their association with the Nerve identified at operation/ root grooved was studied. There was an root of tooth just touching upper white line was observed in 1 out of 11 Nerve identified at operation (root grooved) close cases and was the most statistically significant sign noted. p = 0.0038 (<0.05). Also darkening of the root was observed with p=0.0277(<0.05). Out of total 50 cases Type 2(8%) was most common in males; in females Type 2 (14%) and Type 4 (14%) were more common. Conclusion: In our study Type 2 (Root of tooth just touching upper white line) was most commonly observed. Risks of nerve damage during operation were more significant in Type 2 and Type 4.