Mandibular canal branching presented a high prevalence in CBCT imagery, more frequently located in regions of the premolar and retromolar. An adequate diagnosis of the MCB is necessary to perform dental procedures and verify possible associated pathologies.

Objectives: The purpose of this systematic review was to answer the focus question: “Could the gray values (GVs) from CBCT (cone beam computed tomography) be converted to Hounsfield units (HUs) in multidetector computed tomography (MDCT)?” Methods: The included studies try to answer the research question according to the PICO strategy. Studies were gathered by searching several electronic databases and partial grey literature up to January 2021 without language or time restrictions. The methodological assessment of the studies was performed using The Oral Health Assessment Tool (OHAT) for in vitro studies and the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) for in vivo studies. The Grading of Recommendations Assessment, Development and Evaluation (GRADE system) instrument was applied to assess the level of evidence across the studies. Results: 2710 articles were obtained in Phase 1, and 623 citations remained after removing duplicates. Only three studies were included in this review using a two-phase selection process and after applying the eligibility criteria. All studies were methodologically acceptable, although in general terms with low risks of bias. There are some included studies with quite low and limited evidence estimations and recommendation forces; evidencing the need for clinical studies with diagnostic capacity to support its use. Conclusions: This systematic review demonstrated that the GVs from CBCT cannot be converted to HUs due to the lack of clinical studies with diagnostic capacity to support its use. However, it is evidenced that three conversion steps (equipment calibration, prediction equation models, and a standard formula (converting GVs to HUs)) are needed to obtain pseudo Hounsfield values instead of only obtaining them from a regression or directly from the software.

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Background The mandibular opening path movements have different directions according to the craniofacial morphology of the patient but always downward and backward, therefore increasing the collapse of the upper airway. The aim of this work is to determine if there is a relationship between the craniofacial morphology and the mandibular movement to help understand the impact on the mandibular position. Methods 52 students with full permanent dentition aged 19 to 23 years (mean 21.3 SD 1.7; 29 females and 23 males), participated in the study. Each subject had a lateral cephalometric radiograph taken. The opening angle was determined for two levels of vertical openings at 5 and 10 mm. Results The opening angle showed a greater variability between subjects ranging from 63.15 to 77.08 for 5 mm angle and from for 61.65 to 75.72 for the 10 mm angle. Differences of facial phenotypes was evident when comparing the individual dissoccluding angle of the low angle horizontal pattern and high angle vertical pattern. Conclusions The opening angle is related to craniofacial morphology with higher vertical anterior and shorter anteroposterior faces having a more horizontal path of mandibular movement than shorter vertical anterior and longer anteroposterior subjects who have a more vertical path.

DE CASTRO, M. A. A.; VICH, M. O. L.; ABREU, M. H. G. & MESQUITA, R. A.Cross-sectional study of mandibular canal branching in regions affected by dental inflammation with cone beam computed tomography. Int. J. Odontostomat., 13(2):142-149, 2019. ABSTRACT:The present study aimed to investigate the occurrence of mandibular canal alterations in regions with dental inflammation by means of cone beam computed tomography (CBCT). A database of 2,484 CBCTs was reviewed for identifying dental inflammation in mandibular alveolar ridges. The final sample consisted of 150 CBCTs, including 91 females and 59 males, with ages ranging from 13 to 89 years (mean age of 47.06; ± SD=18.722). The presence and location of dental inflammation, gender, age, as well as presence and location of mandibular canal branching (MCB) were evaluated. The Kolmogorov-Smirnov, Chi-square, and T-test were applied to verify the statistical relationship of the data. There were 178 images of dental inflammation on 150 CBCTs, mainly located at molars' region (75 %). Apical lesions were the most common type of dental inflammation found (79 or 44.4 % of the sample), followed by pericoronitis (32; 18.0 %). This study identified 135 mandibular canal branches in the exams that presented dental inflammation. The MCB were also most commonly located at molars' region (74.07 %). No statistical difference was identified regarding the distribution of mandibular canal branching in relation to the sites with dental inflammation (p=0.370).The MCB found were mostly single (86 or 63.7 % of the total). Sex had no influence on mandibular canal branching occurrence (p=0.308), not did age (p=0.728). A high prevalence of mandibular canal branching was observed in the regions where dental inflammation were identified, most commonly found in the molar region.KEY WORDS: radiology, diagnosis, clinical assessment, cone beam computed tomography, inferior alveolar nerve, mandibular canal. Castro et al. (2015) verified classifications of these anatomical variations and detected that they were performed mainly based on two-dimensional exams DE CASTRO, M. A. A.; VICH, M. O. L.; ABREU, M. H. G. & MESQUITA, R. A. Cross-sectional study of mandibular canal branching in regions affected by dental inflammation with cone beam computed tomography. DE CASTRO, M. A. A.; VICH, M. O. L.; ABREU, M. H. G. & MESQUITA, R. A.Cross-sectional study of mandibular canal branching in regions affected by dental inflammation with cone beam computed tomography. Int. J. Odontostomat., 13(2):142-149, 2019.