Prevalence, dimension and location of retromolar canal on cone beam computed tomography: An Analytical cross sectional study

Background and objectives: The retromolar canal is an anatomical variant that needs consideration in local anesthesia and surgical procedures involving the retromolar area. Complications such as local anesthetic insufficiency, a sensory deficit, hemorrhage and traumatic neuroma may arise in the absence of recognition of these variants. The aim of this study is to determine the prevalence and course of retromolar canal in the Iranian population. Methods: This study is a descriptive cross sectional study. The cross sectional sagittal and three dimensional images from volumetric CBCT. data of 270 patients were reconstructed using on demand imaging analysis software. Retromolar canals were classified into two types according to the courses. The width and location (distance from the third molar) of retromolar canals were evaluated. Results were analyzed with SPSS 20 software and were assessed using the t_test and chi_square test. Results: Retromolar canal was observed in 9/25 % of patients. The mean width of the retromolar foramen was 1/43 mm, and the mean distance from anterior border of retromolar foramen to the distal CEJ of the second molar was 13/33 mm. Conclusion: The prevalence of retromolar canals in the Iranian population was lower than that was reported in previous studies. It can be observed in 9/25 % of Iranian patients.  Damage to the retromolar canal may be unavoidable during surgical procedures may result in paresthesia, excessive bleeding, postoperative hematoma, or traumatic neuroma. Therefore, the clinician must pay particular attention to the identification of a retromolar canal by preoperative radiographic examination and additional CBCT scanning is recommended.

Keywords:

CBCT , Retromolar canal , Retromolar foramen , Mandibular canal , Inferior alveolar canal