A cone beam computed tomography image analysis method to evaluate the inferior alveolar nerve canal with its associated anatomical structures and variations: A retrospective study

Objective: The aim of this study was to produce a systematic method of CBCT image analysis to investigate the Inferior Alveolar Nerve Canal (IANC) trajectory along with its associations and variations and to provide evidence that the visibility of the IANC and its prolongation on CBCT imaging can be detected as a one continuous component, starting from the Mandibular Foramen (MaF) through the Mental Foramen (MeF), and ending as the Mandibular Incisive Canal (MIC) at the midline region. Materials and Methods: This study was a retrospective, cross-sectional review of CBCT images from 200 patients were evaluated by two Dentomaxillofacial radiologists, identical method to investigate the following image parameters: Mandibular Foramen (MaF), types of Mandibular Canals (MaC), Mental Foramen (MeF), types of Mental Canals including: length, symmetry and angulations, visibility of Mandibular Incisive Canal(MIC), types of Lateral Lingual Vascular Canals(LLVCs); including length, height, orientation, location, and opening aspect, Nutrient Canals (NC) number and range between teeth, as well as types of Lingual Foramen (LF)and their associated canals(LC); according to number, orientation, location in relation to the genial tubercles and opening aspect. Results:The visibility of the MIC was detected in the 200 (100%) images.In regards to gender, andamongst all the measured image parameters,the right and left MeC length, the LLVCs range on the right side, and theLC location in relation to genial tuberclesare statistically significant; 0.000, 0.006, 0.002 and 0.020respectively.There was a strong positive correlation between the LLVCs' orientation and the LLVCs' heightat the measurement site.There was a moderate positive correlation between the MeC orientations on the right side with that on the left side, and between the MeC lengths on right and left sides.There was a weak positive correlation between the LLVCs number and length on the right sideand the LLVCs number and length on the left, between the right LLVCs' orientation and the left LLVCs' orientation when there was one canal, between the number of the MaCon the right and left sides, andbetween the number of the MaCon the left side and the number of MeFon the same side. Conclusion: To avoid the potential of any unexpected risks,prior to surgical insertion of dental implants in the vicinity of the IANC, and in consideration to the variable values, and anatomical variation and associations at that vicinity; the inclusion of a"systematic method of CBCT image analysis" evaluation in the "Radiology Report" is essential. Key words: CBCT, image analysis method, Inferior Alveolar Nerve Canal, Mandibular Canal, Retromolar Canal, Accessory Mental Foramina, Mental Canal, Anterior loop, Mandibular Incisive Canal, Lateral Lingual Vascular Canals, Nutrient Canals, Lingual Canals, Lingual Foramen.