Search Results (4)

Objective: To evaluate mandibular kinematics in an orthodontic population using the Modjaw^® optical jaw tracking system. Materials and methods: A total of 154 orthodontic patients underwent mandibular kinematic analysis using the Modjaw^® system. ANB values determined skeletal classification, while dental classification was assessed on digital casts. The Modjaw^® records were taken as instructed by the manufacturer, and data collected from the readings included the discrepancy between centric occlusion and maximum intercuspation, maximum opening, Bennett angles, and sagittal condylar guidance. The presence or absence of temporomandibular disorders was determined by the DC-TMD questionnaires. Non-parametric tests and Spearman correlations were applied for the statistical analysis. Results: Significant differences in mandibular kinematics were observed between skeletal classes, particularly in CO-MI discrepancies, Bennett angles, and maximum opening (p < 0.05). TMD symptoms were associated with higher absolute CO-MI discrepancies but did not significantly alter other kinematic parameters. Weak correlations were found between sagittal condylar guidance and anterior guidance variables. Conclusions: Mandibular kinematics differ by skeletal classification, with Class III patients demonstrating distinct patterns. While TMD symptoms impact CO-MI discrepancies, overall mandibular dynamics remain consistent. Full article

Background: Assessment of functional occlusion is crucial in orthodontics and prosthodontics. With scientific advancements, optical jaw tracking systems are increasingly used to evaluate mandibular kinematics. Objectives: To compare the performance of an optical jaw tracking system (Modjaw^®) and a traditional condylar position indicator (CPI) in identifying condylar position discrepancies within an orthodontic population. A secondary objective was to explore the association between condylar discrepancies and temporomandibular disorders (TMD). Methods: Measurements were collected from 132 patients consecutively recruited from the private practice of a coauthor, using Modjaw and CPI, analyzing discrepancies in the sagittal, vertical, and transverse planes. TMD presence was determined clinically and using the DC-TMD questionnaire. Receiver operating characteristic (ROC) curves and diagnostic metrics were used to evaluate the tools’ performance. Results: No correlation was found between CPI and Modjaw measurements. CPI did not effectively discriminate between patients with and without TMD, with areas under the curve (AUC) not statistically significant. In contrast, the AUCs for Modjaw were 0.683 for the vertical plane (p = 0.001), 0.654 for the sagittal plane (p = 0.004), and 0.777 for the transverse plane (p < 0.001). The cut-off values for TMD screening using Modjaw were established at 2 mm (vertical), 1 mm (sagittal), and 0.5 mm (transverse), exhibiting some specificity, especially in the transverse dimension, but very low sensitivity. Conclusions: No correlation was found between Modjaw and CPI for assessing condylar position discrepancies. While these discrepancies may aid orthodontic treatment planning, they lack sufficient sensitivity for reliable TMD diagnosis. Modjaw’s cut-off points may help exclude TMD risk in orthodontic patients. Full article

Background/Objectives: Eccentric bruxism is a complex parafunctional activity that involves grinding of teeth and occurs more frequently during sleep. This study aimed to assess differences in condylar parameters (sagittal condylar inclination -SCI and Bennett angle -BA) and mandibular and condylar kinematics during functional and parafunctional movements in bruxers and non-bruxers and to assess a digital method for quantifying eccentric bruxism using an optical jaw tracking system (Modjaw^®). Methods: The study group included subjects diagnosed with eccentric bruxism according to validated clinical diagnostic criteria. A control group of non-bruxer subjects with demographic characteristics similar to the study group was considered. Each participant underwent Modjaw^® examination twice to assess the recordings’ repeatability. The anterior guidance, mastication, and simulated eccentric bruxism were recorded. The SCI and BA were computed. The trajectories of interincisal inferior point (IIP), left condyle (LC), and right condyle (RC) in the frontal (F), sagittal (S), and horizontal (H) planes were outlined in rectangles to calculate areas of mastication and areas of eccentric bruxism (mm²). Intraclass correlation coefficient (ICC) was used to assess the recordings’ repeatability. Comparisons between groups were performed using Student’s t- and Mann–Whitney tests. The receiver–operator characteristic (ROC) curve was used to assess the diagnostic quality of the digital method. Results: Twenty bruxers (10 F and 10 M) and 20 non-bruxers (10 F and 10 M) were included. The ICC had values higher than 0.85. SCI, BA, and area of mastication for IIP, LC, and RC were similar between the groups (p > 0.05). The area of eccentric bruxism was significantly wider in the bruxers (p < 0.001). According to the ROC curve, the following cut-off areas (mm²) for eccentric bruxism were found in F, S, and H planes: IIP (18.05, 13.43, 16.28); LC (3.74, 10.83, 3.35); and RC (4.21, 10.63, 2.9), corresponding to sensitivity > 0.8, specificity > 0.75 and area under the curve (AUC) > 0.85. Conclusions: Mandibular and condylar kinematics during functional movements were similar in bruxers and non-bruxers. A novel digital method for quantifying eccentric bruxism was found using Modjaw^®, which could serve as a tool for early detection of eccentric bruxism before the onset of clinical consequences. Full article

The twelve cranial nerves play a crucial role in the nervous system, orchestrating a myriad of functions vital for our everyday life. These nerves are each specialized for particular tasks. Cranial nerve I, known as the olfactory nerve, is responsible for our sense of smell, allowing us to perceive and distinguish various scents. Cranial nerve II, or the optic nerve, is dedicated to vision, transmitting visual information from the eyes to the brain. Eye movements are governed by cranial nerves III, IV, and VI, ensuring our ability to track objects and focus. Cranial nerve V controls facial sensations and jaw movements, while cranial nerve VII, the facial nerve, facilitates facial expressions and taste perception. Cranial nerve VIII, or the vestibulocochlear nerve, plays a critical role in hearing and balance. Cranial nerve IX, the glossopharyngeal nerve, affects throat sensations and taste perception. Cranial nerve X, the vagus nerve, is a far-reaching nerve, influencing numerous internal organs, such as the heart, lungs, and digestive system. Cranial nerve XI, the accessory nerve, is responsible for neck muscle control, contributing to head movements. Finally, cranial nerve XII, the hypoglossal nerve, manages tongue movements, essential for speaking, swallowing, and breathing. Understanding these cranial nerves is fundamental in comprehending the intricate workings of our nervous system and the functions that sustain our daily lives. Full article