Gender Estimation from Morphometric Measurements of Mandibular Lingula by Using Machine Learning Algorithms and Artificial Neural Networks.

BACKGROUND: Sex determination from the bones is of great importance for forensic medicine and anthropology. The mandible is highly valued because it is the strongest, largest and most dimorphic bone in the skull. AIM: Our aim in this study is gender estimation with morphometric measurements taken from mandibular lingula, an important structure on the mandible, by using machine learning algorithms and artificial neural networks. METHODS: Cone beam computed tomography images of the mandibular lingula were obtained by retrospective scanning from the Picture Archiving Communication Systems of the Department of Oral, Dental and Maxillofacial Radiology, Faculty of Dentistry, Inönü University. Images scanned in Digital Imaging and Communications in Medicine (DICOM) format were transferred to RadiAnt DICOM Viewer (Version: 2020.2). The images were converted to 3-D format by using the 3D Volume Rendering console of the program. Eight anthropometric parameters were measured bilaterally from these 3-D images based on the mandibular lingula. RESULTS: The results of the machine learning algorithms analyzed showed that the highest accuracy was 0.88 with Random Forest and Gaussian Naive Bayes algorithm. Accuracy rates of other parameters ranged between 0.78 and 0.88. CONCLUSIONS: As a result of the study, it is thought that mandibular lingula-centered morphometric measurements can be used for gender determination as well as bones such as the pelvis and skull as they were found to be highly accurate. This study also provides information on the anatomical position of the lingula according to gender in Turkish society. The results can be important for oral-dental surgeons, anthropologists, and forensic experts.

Alternative cone-beam CT method for the analysis of mandibular condylar bone in patients with degenerative joint disease.

OBJECTIVE: The aim of this study was to investigate the use of 3D microstructural bone analysis in patients with degenerative joint disorder (DJD) to enhance the diagnostic capacity of cone beam computed tomography (CBCT) in the evaluation of bone tissue. METHODS: 147 TMJ CBCT images of 88 participants were assessed with regard to DJD in the mandibular condyle. We divided each condyle into 3 groups (0, 1, 2) according to diagnosis of DJD: 0 indicates normal condyles (control individuals), 1 indicates mild erosive osteoarthritic change (EOC) and 2 indicates severe EOC. 3D fractal dimension (FD) was calculated on CBCT images of mandibular condyle and were compared with the radiographic diagnosis of patients. RESULTS: ANOVA test showed that there was statistically significant difference in FD values among each groups. The average FD value of group 0 was 1.971, group 1 was 1.918 and group 2 was 1.863. Lower FD values and more severe degenerative changes were seen in patient group 2. To evaluate the reliability of fractal analysis (FA) method, receiver operating characteristic (ROC) curve analysis was performed. Area under the curve (AUC) was 0.717 (p < 0.001). CONCLUSION: This study provides a preliminary conclusion that fractal analysis may be a helpful tool to enhance the diagnostic capacity of CBCT in the evaluation of DJD.

Evaluation of localisation of mandibular foramen in patients with mandibular third molar teeth using cone-beam computed tomography.

BACKGROUND: It is important to know the correct anatomical location of the mandibular foramen to obtain successful anaesthesia of inferior alveolar nerve and to prevent injury to the mandibular vessels and nerve, during a variety of oral and maxillofacial surgical procedures. The aim of this study is to evaluate localisation of the mandibular foramen in patients with the third molars using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: Cone-beam computed tomography was used to determine the location of the mandibular foramen in 67 patients (totally 99 sides) with unilateral or bilateral impacted mandibular third molars. RESULTS: The distance from the posterior border of the mandibular ramus to mandibular foramen did not differ significantly among the other angulations. But the difference between vertical and horizontal angulation of the impacted mandibular third molars according to 'fd' values (the shortest distance between mandibular foramen and the posterior border of mandibular ramus) was found to be statistically significant (p < 0.05). CONCLUSIONS: The present study provides new information to the literature concerning relationship between the location of the mandibular foramen and the mandibular third molars.

Cone beam computed tomography evaluation of ponticulus posticus in patients with cleft lip and palate: a retrospective radio-anatomic study.

BACKGROUND: Ponticulus posticus (PP) is an abnormal bony bridge on the atlas. It plays a significant role in patients undergoing C1 lateral mass screw procedure. Patients with cleft lip and palate (CLP) have higher risk than patients in general population for the appearance of cervical vertebral anomalies. The purpose of the this study was twofold: to determine the prevalence and characteristics of PP in patients with CLP, and to compare the findings with patients in general population using cone beam computed tomography. MATERIALS AND METHODS: Cone beam computed tomography images from 54 individuals who had undergone surgical repair of cleft lip and/or palate were analysed as the study group. For comparison purposes a control group was randomly selected from 108 patients and matched with the CLP subjects. RESULTS: Although 12 of the 54 (22.3%) patients with surgically repaired cleft lip and/or palate in the study group were identified to have PP, only 10 of the 108 (9.2%) patients in the control group had PP. The distribution of the presence of PP between the groups was statistically significant. CONCLUSIONS: Ponticulus posticus is an important anomaly and the presence of PP is important for patients. PP can have clinical significance in cervical spine surgery as this study has indicated that the likelihood of encountering PP is higher in patients with CLP. We suggest that PP should be taken into account prior to cervical vertebral surgery in patients with CLP. (Folia Morphol 2018; 77, 1: 72-78).