Assessment of Roods and Shehab criteria if one or more radiological signs are present in orthopantomogram and position of the mandibular canal in relation to the third molar apices using cone beam computed tomography: a radiographic study

Aim The aim was to access Roods and Shehab criteria if one or more radiological signs are present in orthopantomogram and position of the mandibular canal in relation to the third molar apices using cone beam computed tomography (CBCT). Materials and methods A total of 25 orthopantomogram radiographs exhibiting close relationship between mandibular third molar apices and mandibular canal according to Roods and Shehab criteria were accessed for cortical integrity along with position of the canal using CBCT. Results CBCT images showed that about 63.8% of the teeth were in contact (loss of cortical integrity) with mandibular canal. All Teeth with two or more radiological signs showed contact. The position of the canal was buccal in 61.7% of cases followed by inferior placement in 23.4% of the cases. Conclusion Risk of injury to inferior alveolar nerve increases if two or more radiological signs are present. In our study buccally placed inferior alveolar nerve was seen in more often therefore operator should not gutter the bone below the middle third of the root and mesial point of application for elevation should be used in cases with radiological signs of close association between the nerve and the root apex.