Jorjani Biomedicine Journal

Background and objectives: An effective factor in choosing the correct place for the dental implant and performing surgical procedures in the posterior regions of mandible is the position of the mandibular canal. Failure to consider this important landmark will damage the inferior alveolar nerve. Considering the widespread use of implants and the precision of the images obtained from CBCT. The aim of this study was to evaluate the rate of visibility of mandibular canal by CBCT in order to prevent damage to the inferior alveolar nerves and arteries.
Material And Methods: In this study, 90 archived CBCT images of patients from a private center of oral and maxillofacial radiology in Yazd that was taken by technician was evaluated during 2012-2019. The visibility of the mandibular canal in reconstructed panoramic images of CBCT was assessed by a dentistry student trained by the maxillofacial radiologist in five areas in different thicknesses on each side. Data were analyzed using SPSS 17 software. Chi-square, and correlation coefficient were done.
Results: In total, in 53.38% of CBCT images both borders of mandibular canal were visible, in 17.95%, only one border was visible (difficult observation) and in 28.7% of cases, lack of visibility of mandibular canal was reported. There was no significant difference between sex, age, side and thickness in mandibular canal visibility (P >0.05).
Conclusion: In more than half of CBCT images, both borders were clearly visible in both right and left sides; therefore we can conclude that CBCT is a useful tool for the observation of mandibular canal before surgeries.

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.