A prospective randomised comparative study on the use of panoramic radiograph and cone beam scan with respect to the outcomes and incidence of inferior alveolar nerve injury after lower third molar removal, and establishing guidelines for the indications of cone beam scan as an adjunct to panoramic radiographs

A known risk factor for lower wisdom teeth removal is inferior alveolar nerve injury, due to the anatomical position and relationship of these two structures. Patients who are referred for wisdom teeth removal routinely have an orthopantomogram for preoperative assessment of these teeth. Cone beam scan, which is a low dose computed tomography scan providing 3-dimension representation of the site, is becoming increasingly popular for inferior alveolar nerve localization. However, there are no studies to show that additional scanning improves outcomes and decreases risk of post-operative numbness for the patient. Furthermore, there are currently no guidelines regarding clear indications for the use of cone beam scan as an adjunct. This project will look at the incidence of postoperative altered inferior alveolar nerve sensation in patients who have lower wisdom teeth removed – in groups where they have the routine orthopantomogram radiograph only, and those who have, in addition to the orthopantomogram radiograph, a cone beam scan. The project will aim to establish evidence based guidelines for the use of Cone beam scan imaging as an adjunctive tool for third molar surgery. Patients who agree to take part in the project will be randomised into two groups – the control is the group without additional imaging ("orthopantomogram only" group), and the intervention group is the group with the additional cone beam scan ("orthopantomogram and Cone beam scan" group). The imaging will be examined with respect to the relationship between the inferior alveolar nerve and lower wisdom teeth. During routine post-operative visits, patients are routinely monitored to establish the presence of inferior alveolar nerve injury. This data will be collected and analysed.