Jorjani Biomedicine Journal

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.

Background and objective: Accurate understanding of the anatomy of the inferior alveolar nerve (IAN) and its relation with anatomical landmarks of mandibular molar teeth can reduce the risk of unwanted injuries to the IAN during implant placement.
Methods: 44 CBCTs of patients,who have been reffered to the private oral and maxillofacial radiology center, were examined by a radiologist on the axial, sagittal and coronal planes. Then, the distances between mandibular canal and buccal cortex (BN) and lingual cortex (LN), buccolingual width of the mandibular canal (BL), and the distances between the canal and apex of the first molar (M1N) and second molar of mandible (M2N) were obtained from cross-sectional images. Data were analyzed using SPSS17 software and  Kolmogorov-smirnov and Mann-whitney test.
Results: 21 males and 23 females aged 20 to 50 years old (mean age: 37.8±7.52) were examined. The mean intervals in the regions of first molar in the right and left sides were BN: 4.03,4.06 mm, LN: 2.10,2.58 mm, BL: 2.20,2.20 mm, and M1N: 5.77,5.78 mm and in the second molar region, on the right and left sides were BN: 5.21,5.20 mm, LN: 1.95,1.80 mm and BL: 2.30,2.20 mm and M2N: 3.85,3.55 mm, respectively. There was a significant difference in the mean buccolingual width of mandibular canal in both sides in the region of first molar and left side in the region of second molar between two genders. (P=0.009, P=0.019, P=0.045). Other measurements were not significantly different between two genders (P>0.05).  The age range of patients had no effect on any of the distances and measurements (P>0.05).
Conclusion: buccolingual width of mandibular canal in both sides in the region of first molar and left side in the region of second molar was associated with gender.