Analysis Of Jaw Movements Research Articles

Analysis of mandibular jaw movements to assess ventilatory support management of children with obstructive sleep apnea syndrome treated with positive airway pressure therapies.

The polysomnography (PSG) is the gold-standard for obstructive sleep apnea (OSA) syndrome diagnosis and assessment under positive airway pressure (PAP) therapies in children. Recently, an innovative digital medicine solution, including a mandibular jaw movement (MJM) sensor coupled withautomated analysis, has been validated as an alternative to PSG for pediatric application. This study aimed to assess the reliability of MJMautomated analysis for the assessment of residual apnea/hypopnea events during sleep in children with OSA treated with noninvasive ventilation (NIV) or continuous PAP(CPAP). In this open-label prospective non-randomized multicentric trial, we included children aged from 5 to 18 years with a diagnosis of severe OSA. The children underwent in-laboratory PSG with simultaneous MJM monitoring and at-home recording with MJM monitoring 3 months later. Agreement between PSG and MJM analysis in measuring the residual apnea-hypopnea index (AHI) was evaluated by the Bland-Altman method. The treatment effect on residual AHI was estimated for both PSG and MJM analysis. Fifteen (60% males) children were included with a median age of 12 years [interquartile range 8-15]. Two (17%) were ventilated with NIV and 13 (83%) with CPAP. There was a good agreement between MJM-AHI and PSG-AHI with a median bias of -0.25 (95% CI: -3.40 to +2.04) events/h. The reduction in AHI under treatment was consistently significant across the three measurement methods: in-laboratory PSGand MJM recordings in the laboratory and at home. Automated analysis of MJM is a highly reliable alternative method to assess residual events in a small population treated with PAP therapies.

Comparison of three-dimensional position of maxillary dentition model treated with two digital transfer methods

Objective: To compare and evaluate the difference in maxillary dentition position using an anatomical facebow and jaw movement analyzer. Methods: From March to May 2023, 15 medical interns from Yantai Stomatological Hospital were recruited, including 9 males and 6 females, aged 20-25 years. Digital models and plaster models of maxillary dentition were obtained from the 15 medical interns. The anatomical facebow group (AFB) and jaw movement analyzer group (JMA) were used to transfer the position of the maxillary dentition to the virtual articulator. The virtual occlusal articulator module of exocad denture design software was used to measure the inclination angle of the occlusal plane of the two groups, the distance between the mesio-incisal angle of the left maxillary central incisor and the lateral center point of the lateral condylar sphere of the virtual occlusal articulator, the distance between the mesial buccal cusp of the maxillary first molar and the lateral center point of the lateral condyle sphere of the virtual articulator. The same marks (mesial incisor point of left maxillary central incisor and mesial buccal cusp point of both maxillary first molars) were measured in two groups of maxillary dentition, and the root-mean-square error between 3 points was calculated. Results: The occlusal plane inclination angle in AFB group (9.11°±3.85°) was significantly larger than that in JMA group (4.94°±2.69°) (t=10.45, P<0.001). There were significant differences between AFB and JMA groups. The distances from the mesial cusp of the left first molar to the lateral center of the left condylar, from the mesial cusp of the left maxillary central incisor to the lateral center of the left condylar[(91.75±3.05), (129.09±4.60) mm]were significantly smaller than those in the JMA group[(95.68±5.45), (132.41±5.64) mm](t=-4.48, P=0.001; t=-4.21, P=0.001). In both groups of models, the distance of the mesial cusp of the left maxillary central incisor was (8.81±2.56) mm, and the distance between mesial buccal cusp of maxillary left first molar was (7.56±2.49) mm, the distance between mesial buccal cusp of maxillary right first molar was (7.13±2.77) mm; the root mean square error was (7.93± 2.94) mm. Compared with 0, the difference was statistically significant (t=10.45, P<0.001). Conclusions: There were differences between the two methods (anatomical facebow and the jaw movement analyzer) for transferring the maxillary dentition position to the three-dimensional space position of the virtual articulator.

Історичні аспекти та сучасні підходи до реєстрації рухів нижньої щелепи

Objective: To systematize and review available scientific research data over twenty years regarding systems and methods for recording lower jaw movements. Materials and Methods: A literature search was conducted on the PubMed service. Publications up to 2024 were considered. The primary filter in the search system was used to select publications based on the following criteria: metaanalysis, review, systematic review. Only publications in English were selected for the initial data set. The primary search yielded 45 publications. After a detailed analysis of the selected publications, 35 publications that best met the needs were retained for further processing. Additionally, 3 publications from other services that addressed the topic were added manually. Thus, the total number of publications used for the analysis amounted to 37 articles. Results: The analysis of lower jaw movements provides the clinician with important parameters for evaluating the function of the temporomandibular joint (TMJ). These parameters are crucial for modeling the normal functioning of the masticatory apparatus. Therefore, in-depth knowledge of lower jaw movements is necessary for dentists of various profiles, especially prosthodontists and orthodontists. Familiarity with various methods used to measure lower jaw movements is key in clinical analysis. The hardware for recording lower jaw movements has evolved significantly from purely mechanical methods to modern electronic systems with multi-functional software, ensuring high-level functional rehabilitation of the dentoalveolar system. Key words: lower jaw, temporomandibular joint, function, registration of lower jaw movements, hardware.

Comparative evaluation of the volume of occlusal adjustment of repositioning occlusal devices designed by using an average value digital articulator and the jaw movement analyzer

Statement of problemThe volume of occlusal adjustment of digital occlusal devices designed with different digital occlusal articulators is unknown. PurposeThe purpose of this clinical study was to evaluate and compare the clinical efficacy and volume of occlusal adjustment of digital occlusal devices designed by using an average value digital articulator and the jaw movement analyzer (JMA). Material and methodsThirty participants were randomly divided into 2 groups, an Average value group and a JMA group, with 15 participants in each group. The centric relation position of the participants was determined by an experienced investigator with the aid of a leaf gauge. An intraoral scanner (TRIOS 3) was used to obtain digital scans of the maxillary and mandibular dentition and the maxillomandibular relationship record in the centric relation position. Personalized articulator parameters of participants in the JMA group were obtained by using a JMA (JMAnalyser). Different articulator parameters were used to fabricate an occlusal device in a denture design software program (exocad DentalCAD). The surface of the occlusal device was coated with a dental optical spray and then scanned by using a laboratory scanner (Kavo LS3). The process was repeated after the occlusal device was adjusted. The files of the 2 scans were imported into a reverse engineering software program, and the root mean square (RMS) values were obtained by best-fit alignment and 3-dimensional comparison. The Shapiro-Wilk normality test and homogeneity of variance test were performed, and t tests were used to evaluate differences in the RMS values between the groups (α=.05). ResultsThe experimental data were generally normally distributed (P>.05). No statistically significant difference was found between the RMS values of the Average and the JMA groups (P>.05). ConclusionsNo significant difference in the volume of occlusal adjustment was found when using occlusal devices made by using the digital average articulator or the JMA, suggesting that either method can be used to program articulators for the fabrication of occlusal devices.

Evaluation of masticatory performance by motion capture analysis of jaw movement.

The assessment of masticatory performance (MP) is conducted in hospitals, but is difficult to perform in nursing facilities that lack specialists in dysphagia. To select the appropriate food textures in nursing practice, a simple method of evaluating the MP should be developed. The purpose of this study was to investigate motion parameters that influence MP by motion capture analysis of maxillofacial movement on chewing gummy jelly in healthy adults. The subjects were 50 healthy adults. The state of chewing gummy jelly was photographed using a high-speed camera. Simultaneously, we evaluated the amount of glucose extracted (AGE) obtained with gummy jelly as a reference value for MP. The subjects were divided into two groups: normal and low masticatory groups (NG and LG, respectively) based on the AGE. The cycle of mastication was classified into 3 phases: closing phase (CP), transition phase (TP), and opening phase (OP) through motion capture analysis of the video photographed. Parameters of jaw movement, and their associations with the AGE were examined. The transition phase rate (TR), and opening phase rate (OR) were correlated with the AGE. Furthermore, the TR in the NG was significantly higher than in the LG, whereas the OR was significantly lower than in the LG. The age, TR, and Opening velocity were significant independent variables. Motion capture technology facilitated the analysis of jaw movement. The results suggested that MP can be evaluated by analyzing the TP and OP rates.

An advanced method of individual jaw movement analysis

An advanced method of individual jaw movement analysis

Individual mandibular movement registration and reproduction using an optoeletronic jaw movement analyzer and a dedicated robot: a dental technique

BackgroundFully adjustable articulators and pantographs record and reproduce individual mandibular movements. Although these instruments are accurate, they are operator-dependant and time-consuming. Pantographic recording is affected by inter and intra operator variability in the individuation of clinical reference points and afterwards in reading pantographic recording themselves. Finally only border movements can be reproduced.MethodsBionic Jaw Motion system is based on two components: a jaw movement analyzer and a robotic device that accurately reproduces recorded movements. The jaw movement analyzer uses an optoelectronic motion system technology made of a high frequency filming camera that acquires 140frames per second and a custom designed software that recognizes and determines the relative distance at each point in time of markers with known geometries connected to each jaw. Circumferential modified retainers connect markers and do not cover any occlusal surfaces neither obstruct occlusion. The recording process takes 5 to 10 s. Mandibular movement performance requires six degrees of freedom of movement, 3 rotations and 3 translations. Other robots are based on the so-called delta mechanics that use several parallel effectors to perform desired movements in order to decompose a complex trajectory into multiple more simple linear movements. However, each parallel effector introduces mechanical inter-component tolerances and mathematical transformations that are required to transform a recorded movement into the combination of movements to be performed by each effector. Bionic Jaw Motion Robot works differently, owing to three motors that perform translational movements and three other motors that perform rotations as a gyroscope. This configuration requires less mechanical components thus reducing mechanical tolerances and production costs. Both the jaw movement analyzer and the robot quantify the movement of the mandible as a rigid body with six degrees of freedom. This represents an additional advantage as no mathematical transformation is needed for the robot to reproduce recorded movements.ResultsBased on the described procedure, Bionic Jaw Motion provide accurate recording and reproduction of maxillomandibular relation in static and dynamic conditions.ConclusionThis robotic system represents an important advancement compared to available analogical and digital alternatives both in clinical and research contexts for cost reduction, precision and time saving opportunities.

Functional Analysis of Rhythmic Jaw Movements Evoked by Electrical Stimulation of the Cortical Masticatory Area During Low Occlusal Loading in Growing Rats.

The maturation of rhythmic jaw movements (RJMs) and related neuromuscular control has rarely been studied in animals, though this process is essential for regulating the development of stomatognathic functions. Previous studies have shown that occlusal hypofunction during growth alters masticatory performance. However, little is known about patterns of cortically-induced RJMs under conditions of soft-diet feeding during development. The aim of this study is to clarify the effect of low occlusal loading on the pattern of cortically induced RJMs and related neuromuscular responses in growing rats. Sixty-four 2-week-old male albino Wistar rats were randomly divided into two groups and fed on either a normal diet (control) or soft diet (experimental) soon after weaning. At 5, 7, 9, and 11 weeks of age, electromyographic (EMG) activity was recorded from the right masseter and anterior digastric muscles along with corresponding kinematic images in RJMs during repetitive intracortical microstimulation of the left cortical masticatory area (CMA). Rats in both groups showed an increase in gape size and lateral excursion until 9 weeks of age. The vertical jaw movement speed in both groups showed no significant difference between 5 and 7 weeks of age but increased with age from 9 to 11 weeks. Compared to the control group, the average gape size and vertical speed were significantly lower in the experimental group, and the pattern and rhythm of the jaw movement cycle were similar between both groups at each recording age. EMG recordings showed no age-related significant differences in onset latency, duration, and peak-to-peak amplitude. Moreover, we found significantly longer onset latency, smaller peak-to-peak amplitude, and greater drop-off mean and median frequencies in the experimental group than in the control group, while there was no significant difference in the duration between groups. These findings indicate that a lack of enough occlusal function in infancy impedes the development of patterns of RJMs and delays the neuromuscular response from specific stimulation of the CMA.

Measurement and Analysis of Jaw Movements

Measurement and Analysis of Jaw Movements

顎運動測定器とCADソフトウェアを用いた咀嚼運動と咬合接触点推移の3次元表示

顎運動測定器とCADソフトウェアを用いた咀嚼運動と咬合接触点推移の3次元表示

Electrognathographic Analysis of Jaw Movements during Speech: An Exploratory Study

The purpose of the study was to compare the mandibular movement during speech in patients with temporomandibular disorder (muscular TMD) and in asymptomatic volunteers using computerized electrognathography. Twelve asymptomatic volunteers (Group I control group) and 12 patients with muscular TMD (Group II) were selected. Both groups were subjected to a phonetic test and evaluated according to: maximum mandibular opening amplitude (mm), mandibular velocity during opening and closing (mm/sec) and maximum lateral deviation to both right and left sides (mm). Regarding to the mandible movements both frontal and horizontal planes, as well as the mandible deviations, there was no difference between Group I and Group II for all parameters analyzed. Regarding to the mandible movements in frontal and horizontal planes as well as the mandible deviations, there was no difference between group I and group II (muscular TMD and Asymptomatic). There was a statistical difference for the maximum mandibular velocity during opening and closing during speech in symptomatic patients.

Effects of aspiration and vowel context on lip and jaw kinematics in Cantonese bilabial plosive production

The present study examined the possible effects of aspiration and vowel context on lip and jaw movements during production of Cantonese bilabial plosives /p/ and /ph/. VCV syllables were randomly produced by 30 adult native Cantonese speakers. Movement of upper lip, lower lip, and jaw during speech production was recorded using electromagnetic articulography. Kinematic analysis of lip and jaw movements during the opening phase of bilabial plosive production revealed a significant aspiration effect, especially on vertical displacement and velocity of the jaw. Such effects were consistent across all vowel contexts. Similarly, a significant aspiration effect was observed in vertical displacement of the lower lip. These findings suggest that muscular force is the main driving force in the production of unaspirated bilabial plosives.

EFECTELE BENEFICE ALE SUPRAPROTEZĂRII PE MINIIMPLANTURI LA EDENTATUL TOTAL MANDIBULAR EVIDENŢIATE KINEZIOGRAFIC

Introduction. Miniimplant overdenture is a treatment option with numerous subjective and objective benefits for the edentulous patient. Aim. This study aims to analyse the changes and benefi ts in terms of mandibular movements, that occur in the process of transforming conventional dentures into miniimplant supported overdentures, through kinesiograph exam with the JMA system (Jaw Motion Analyser, Zebris, Isny im Allgäu, Germany). Material and methods. For the study we used ultrasonic kinesiography with the JMA system (Jaw Movement Analysis, Zebris, Isny im Allgäu, Germany), connected to a computer, which enables recording, documenting and processing of the functional data from the edentulous patients. A series of kinesiographic exams were undertaken, using the JMA system Zebris), with conventional dentures with and without denture adhesive, after insertion of mini dental implants (mini SKY, Bredent, Senden, Germany), with the denture soft lined and after O-rings were applied. Conclusion. Kinesiographic recordings show positive changes of the measured data and confirm the benefits of the treatment, subjectively reported by patients.

Kinematic and Diffusion Tensor Imaging Definition of Familial Marcus Gunn Jaw-Winking Synkinesis

BackgroundMarcus Gunn jaw-winking synkinesis (MGJWS) is characterized by eyelid ptosis, which disappears during jaw movement. Familial MGJWS is an extremely rare condition. Some authors suggested that MGJWS is due to neural misdirection in the brainstem whereas others suggested that aberrant reinnervation or ephapse may be responsible for synkinetic activity. Pathogenesis of this condition is therefore still unclear.Methodology/Principal FindingsTo investigate pathogenetic mechanism in familial MGJWS we performed neurophysiological (EMG, Blink Reflex, Recovery cycle of the R2 component of the blink reflex, Masseter inhibitory reflex, BAEPS and kinematic analysis) and neuroradiological (MRI, Diffusion Tensor Imaging) investigations in a member of a multigenerational family with autosomal dominant Marcus Gunn jaw-winking synkinesis (MGJWS). Kinematic analysis of eyelid and jaw movements disclosed a similar onset and offset of the eyelid and jaw in both the opening and closing phases. The excitability of brainstem circuits, as assessed by the blink reflex recovery cycle and recovery index, was normal. Diffusion Tensor Imaging revealed reduced fractional anisotropy within the midbrain tegmentum.Conclusions/SignificanceKinematic and MRI findings point to a brainstem structural abnormality in our familial MGJWS patient thus supporting the hypothesis of a neural misdirection of trigeminal motor axons to the elevator palpebralis muscle.

Proposal of a Masticatory Robot for Analysis of Jaw Movements

In this paper, a life-sized jaw mechanism is proposed on the basis of biological masticatory structure. Its actual parameters are defined in Solidworks according to human masticatory systems, the trajectory and position error of masticatory robot is performed via ADAMS and Matlab. The simulation results have shown that the robotic jaw is able to reproduce the human behavior. However, because the mechanism is a highly coupled and nonlinear system, the position error cannot be eliminated completely, and more sophisticated control system is required in future study.

Measurement of jaw motion: the proposal of a simple and accurate method

The analysis of jaw movements has long been used as a measure for clinical diagnosis and assessment. A number of strategies are available for monitoring the trajectory; however most of these strategies make use of expensive tools, which are often not available to many clinics in the world. In this context, this research proposes the development of a new tool capable of quantifying the movements of opening/closing, protrusion and laterotrusion of the mandible. These movements are important for the clinical evaluation of both the temporomandibular function and muscles involved in mastication. The proposed system, unlike current commercial systems, employs a low-cost video camera and a computer program, which is used for reconstructing the trajectory of a reflective marker that is fixed on the jaw. In order to illustrate the application of the devised tool a clinical trial was carried out, investigating jaw movements of 10 subjects. The results obtained in this study were compatible with those found in the literature with the advantage of using a low-cost, simple, non-invasive and flexible solution customized for the practical needs of clinics. The average error of the system was less than 1.0%.

Correlation analysis of craniomandibular index and gothic arch tracing in patients with craniomandibular disorders

Complex etiology and symptomatology of craniomandibular dysfunction make the diagnosing and therapy of this disorder more difficult. The aim of this work was to assess the value of clinical and instrumental functional analyses in diagnosing of this type of disorders. In this study 200 subjects were examined, 15 with temporomandibular joint disorder. They were subjected to clinical functional analysis (Fricton-Shiffman) and instrumental functional analysis by using the method of gothic arch. The parameters of the gothic arch records were analyzed and subsequently compared among the subjects of the observed groups. In the examined group of the population 7.5% of them were with craniomandibular dysfunction. The most frequent symptoms were sound in temporomandibular joint, painful sensitivity of the muscles on palpation and lateral turning of the lower jaw while opening the mouth. By analyzing the gothic arch records and comparing the obtained values between the observed groups it was assessed that: lateral and protrusion movements, lateral amplitude and the size of gothic arch were much bigger in the healthy subjects, and latero-lateral asymmetry was larger in the sick subjects. Latero-lateral dislocation of apex was recorded only in the sick subjects with average values of 0.22 +/- 0.130 mm. The correlation between the values of Fricton-Shiffman craniomandibular index and the parameters of the gothic arch records and latero-lateral amplitude and dislocation of apex records were established by correlative statistical analysis. Functional analysis of orofacial system and instrumental analysis of lower jaw movements (gothic arch method) can be recommended as precise and simple methods in diagnosing craniomandibular dysfunctions.

Analysis of masseter muscle oxygenation and jaw movement during experimental gum chewing with different hardness

"Analysis of masseter muscle oxygenation and jaw movement during experimental gum chewing with different hardness." Orthodontic Waves, 69(4), p. 129

Development of an Ultra-Miniaturized Inertial Measurement Unit for Jaw Movement Analysis during Free Chewing

Problem statement: Jaw movement analysis, as a clinical aid, can provide an objective basis for understanding and diagnosing jaw musculoskeletal disorders. Therefore, the use and development of devices for quantitatively measuring and analyzing jaw movement have become more common and popular in the clinic. Many types of jaw tracking devices have been developed, but most of them are still not handy and easy to be used. Approach: To improve the handiness and utility of the jaw movement analysis devices, we developed a simple to be used jaw tracking prototype by using a new ultra-miniaturized Inertial Measurement Unit (IMU) named WB-3. The WB-3 IMU was composed by 3-axis gyroscope, 3-axis accelerometer and 3-aixs magnetometer, which can not only measure the acceleration and angular speed of jaw movement, but also can measure mouth opening angle. The IMU’s extremely reduced weight and size allowed it to be easily adhered to mandible during normal tests without physical restriction to the subjects. A preliminary experiment for jaw movement analysis during free chewing of three types of food with different shapes and hardness was evaluated. A group of 15 healthy subjects aged from 21-36 years old kindly participated in the experiment. Results: The parameters of chewing time, chewing frequency, power spectrum density of jaw’s angular speed and acceleration, cumulative distribution function of jaw’s acceleration and mouth opening angle were presented. The experimental results clearly showed that the subjects used less chewing time, less chewing frequency, less acceleration cumulative distribution and energy to eat soft food; higher values were found in the case of hard food and there was no significant difference in mouth opening angle while eating these three foods. Conclusion: Our jaw movement analysis prototype using IMU WB-3 was proved to be a valid and handy method for jaw movement and pattern analysis which may be used clinically as an assistant system for dental therapy.

Anatomical location of various condylar points for jaw movement analysis in Japanese women

The aim of this study was to determine anatomical locations of the hinge axis point, kinematic axis point and reference point for the palpated lateral condylar pole on lateral cephalograms. Subjects comprised 18 Japanese women selected according to following criteria: normal occlusion; and absence of signs and symptoms of stomatognathic function. Jaw movement and the condylar reference points noted earlier were recorded three-dimensionally with six degrees of freedom, and kinematic axis point and hinge axis point were determined using an optoelectronic jaw-tracking system. Lateral cephalograms were used to determine anatomical locations of the three points in the condyle. Mean location of hinge axis point was 12.9 mm anterior of the porion and 5.3 mm inferior to the Frankfort horizontal plane, the kinematic axis point was situated in 12.8 mm anterior and 0.1 mm inferior, and the reference point for the palpated lateral condylar pole was situated 10.7 mm anterior and 0.8 mm inferior, respectively. The kinematic axis point was located outside the condyle in the majority of subjects. The reference point for the palpated lateral pole offers a useful indicator in the analysis of condylar movements.