Exploratory analysis of new craniometric measures for the investigation of biological sex using open-access statistical and machine-learning tools on a cone-beam computed tomography sample.

Investigation of the biological sex of human remains is a crucial aspect of physical anthropology. However, due to varying states of skeletal preservation, multiple approaches and structures of interest need to be explored. This research aims to investigate the potential use of distances between bifrontal breadth (FMB), infraorbital foramina distance (IOD), nasal breadth (NLB), inter-canine width (ICD), and distance between mental foramina (MFD) for combined sex prediction through traditional statistical methods and through open-access machine-learning tools. Ethical approval was obtained from the ethics committee, and out of 100 cone beam computed tomography (CBCT) scans, 54 individuals were selected with all the points visible. Ten extra exams were chosen to test the predictors developed from the learning sample. Descriptive analysis of measurements, standard deviation, and standard error were obtained. T-student and Mann-Whitney tests were utilized to assess the sex differences within the variables. A logistic regression equation was developed and tested for the investigation of the biological sex as well as decision trees, random forest, and artificial neural networks machine-learning models. The results indicate a strong correlation between the measurements and the sex of individuals. When combined, the measurements were able to predict sex using a regression formula or machine learning based models which can be exported and added to software or webpages. Considering the methods, the estimations showed an accuracy rate superior to 80% for males and 82% for females. All skulls in the test sample were accurately predicted by both statistical and machine-learning models. This exploratory study successfully established a correlation between facial measurements and the sex of individuals, validating the prediction potential of machine learning, augmenting the investigative tools available to experts with a high differentiation potential.

Observational and descriptive analysis of broken dental needles: a case series.

PURPOSE: To discuss potential causes of broken dental needles during dental anesthesia and features of this complication, including the anatomical location of fragments in tissues, symptoms, complications, and therapeutic approaches. METHODS: Twelve cases of broken dental needles occurring during dental anesthesia and subsequently referred to Hospital de Base do Distrito Federal, Brazil, between 1992 and 2019 were selected. In addition, similar cases reported in the literature over the past 50 years were reviewed. RESULTS: Needle fractures occur most frequently during inferior alveolar nerve blocks and in younger patients. The leading cause is unexpected patient movement during the anesthetic procedure. The needle fragment is most commonly found in the pterygomandibular space or the deep spaces of the head and neck region. Needle migration is a particular concern; although rare, it is unpredictable and potentially life-threatening. CONCLUSIONS: Needle fracture is an intraoperative complication which has the potential to cause severe patient damage. It is essential that practitioners have knowledge of this possible complication and understand the technical considerations for its prevention. The existing literature and the results of this case series analysis suggest that removal of the fractured needle fragment should be attempted as soon as possible.

Color translation from monoscopic photogrammetry +ID Methodology into a Polyjet final 3D printed facial prosthesis.

Background: The artistic techniques necessary to fabricate facial prostheses mainly depend on individual skill and are not a resource easily reproduced. Digital technology has contributed to improved outcomes, often combining analog and new digital techniques in the same workflow. Methods: This article aims to present an innovative workflow to produce a final colored 3D printed and facial prosthesis by UV-map color translation into colored resin 3D printing. A modified +ID Methodology was used to obtain 3D models with the calibrated 3D printable patient's skin color. No hands-on physical molding, manual sculpture, or intrinsic silicone coloration was used. Results: The outcome resulted in acceptable aesthetics, adaptation, and an approximate color match after extrinsic coloration. The patient reported good comfort and acceptance. Conclusions: A direct resin 3D printed prosthesis may be a viable alternative, especially for rapid delivery as an immediate prosthesis or an option when there is no experienced anaplastogist to manufacture a conventional prosthesis.

Accuracy of three-dimensional virtual simulation of the soft tissues of the face in OrtogOnBlender for correction of class II dentofacial deformities: an uncontrolled experimental case-series study.

PURPOSE: To assess whether virtual simulations of the projection of the soft tissues of the face after class II bimaxillary orthognathic surgery, generated from 3D reconstruction of preoperative computed tomography (CT) scans, differed significantly from the actual soft tissue profile obtained in the late postoperative period (beyond 6 months). Secondarily, to validate the accuracy of a free, open-source software suite for virtual soft tissue planning in orthognathic surgery. METHODS: Helical CT scans were obtained pre- and postoperatively from 16 patients with Angle class II malocclusion who underwent bimaxillary orthognathic surgery. A comparative study between soft tissue meshes constructed for surgical simulation (M1) and the actual meshes obtained from postoperative scans (M2) was then performed. To establish the accuracy of 3D facial soft tissue simulation in a free and open-source software suite (OrtogOnBlender-OOB), 17 predetermined anatomic landmarks were measured in M1 and M2 scans after alignment of cranial structures. RESULTS: The mean error between preoperative simulations and actual postoperative findings was < 2 mm for all anthropometric landmarks. The overall average error for the facial soft tissues was 1.07 mm. CONCLUSION: Comparison between preoperative simulation (M1) and actual postoperative findings (M2) showed clinically relevant ability of the method to reproduce actual surgical movement reliably (< 2-mm error). OOB is capable of accurate soft tissue planning for orthognathic surgery, but mesh deformation methods still require improvement. TRIAL REGISTRATION: RBR-88jff9. Retrospectively registered at Brazilian Registry of Clinical trials-ReBec ( http://www.ensaiosclinicos.gov.br ) May 06, 2020.

Unilateral mandibular condylar process fractures: a retrospective clinical comparison of open versus closed treatment.

PURPOSE: To retrospectively compare the clinical outcomes of closed treatment (closed reduction and intermaxillary fixation) with open treatment (open reduction and internal fixation with miniplates and screws) of unilateral mandibular condylar process fractures. METHODS: Adult patients with unilateral condylar fractures treated from January 2011 to July 2013 in the Oral and Maxillofacial Surgery Service at the Base Hospital of the Federal District, Brazil, were invited to participate. Those who agreed to participate were scheduled for clinical evaluation, which consisted of a subjective questionnaire (completed by the examiner) and an objective physical examination of the temporomandibular joints and mandibular range of motion. The following variables were analyzed: mouth opening; lateral excursions of the mandible; presence of clicking; mandibular function impairment (speech, chewing); and occlusion. RESULTS: Seventeen patients (15 men and 2 women) attended the scheduled appointment: 9 had received open treatment (surgical) and 8 had received closed treatment (nonsurgical). Patients were evaluated at 6-30 months postoperatively. Only maximum mouth opening (p = 0.044) and maximum lateral excursion to the unaffected side (p = 0.030) showed a significant difference between the closed and open treatment groups. CONCLUSIONS: Our findings are consistent with those reported in the literature as both methods (closed and open treatment) produced satisfactory outcomes. The only between-group difference was the amount of maximum mouth opening and lateral excursion to the unaffected side. Further randomized studies with a larger number of patients with condylar process fractures are needed to verify the results obtained with each treatment.