Jaw Movements Research Articles

Is dynamic occlusal design necessary for anterior guidance recovery in the computer-aided design process? An in vitro study

ObjectivesThis study aimed to assess the effectiveness of patient-specific motion in restoring anterior guidance and to investigate the influence of occlusal plane position within a virtual articulator on the design of the anterior guide slope for incisors. MethodsTwenty participants' intraoral scan, occlusal plane position, and jaw motion data were recorded. The maxillary anterior teeth were virtually prepared, and the crowns were designed based on average virtual articulator (AVR), personalized virtual articulator (ART), and patient-specific motion (PSM). The anterior guide slope of maxillary central incisors (S1, S2, Sc, Sp) and the mesio-distal angle (MDA) of the canine of prostheses were compared to that of natural teeth (NAT). One-Way ANOVA was utilized to evaluate the effectiveness of the three methods in restoring the anterior guidance of maxillary anterior teeth. ResultsThe comparison of Sp and MDA showed no significant difference between the PSM and NAT groups (p > 0.05). However, Sp of the ART group was significantly smaller, while MDA was higher than that of the NAT group (p < 0.05). Sp did not differ significantly (p > 0.05) when the angle of the occlusal plane (AOP) was small. As the AOP increased, Sp of the ART and AVR groups were significantly smaller than that of the NAT group (p < 0.05). With a large AOP, Sp of the ART group was notably smaller than that of the NAT group (p < 0.05), while there was no significant difference between the AVR and NAT groups (p > 0.05). ConclusionsOcclusal design based on patient-specific motion proved more effective in restoring natural anterior guidance. The anterior guidance of prostheses designed using a virtual articulator was influenced by occlusal plane position. Clinical SignificanceThe utilization of a jaw motion tracer facilitated the transfer of personalized occlusal plane positions and recorded jaw motion, which can be integrated into the digital prosthetic workflow for virtual occlusion adjustment. Occlusal design based on patient-specific motion more effectively restored lingual guidance of maxillary anterior crowns.

Study of axiography changes in patients with temporomandibular joint dysfunction.

Aim: To determine the effectiveness of treatment of temporomandibular joints muscle and joint dysfunction with occlusive splints based on the analysis of axiography data. Materials and Methods: 274 (two hundred and seventy-four) patients aged 18 to 44 years with a diagnosis of temporomandibular joints dysfunction before and after treatment. Results: All patients with signs of temporomandibular joints dysfunction before treatment had a violation of the movement trajectory of the lower jaw: deviation - 68.7%, diflexion - 31.3%. When opening and closing the mouth, asymmetric shifts of the lower jaw of more than 2 mm were observed. After treatment with occlusive splints, the correct trajectory of opening and closing the mouth was noted: the number of patients with a trajectory violation decreased by 89.1%, and the amount of displacement of the lower jaw during opening and closing the mouth in 92.4% of patients decreased on average to 0.9 mm. When analyzing the movements of the lower jaw in the sagittal plane, deviations of the trajectory of the lower jaw were found in 79% of clinical cases. After the treatment using occlusive splints, 93.4% of cases of mandibular movement trajectory violations in the transversal plane were eliminated, and 78.1% of patients had a reduction in displacement volume to 0.9 mm. When analyzing the movements of the lower jaw in the sagittal plane, deviations of the trajectory of the lower jaw were found in 79% of clinical cases. After the treatment using occlusive splints, 93.4% of cases of mandibular movement trajectory violations in the transversal plane were eliminated, and 78.1% of patients had a reduction in displacement volume to 0.9 mm. Conclusions: Movement trajectories of the lower jaw in the sagittal plane improved in 80.1% of patients, normalization of the position of the lower jaw in relation to the neuromuscular trajectory was achieved in 93.4% of clinical cases. According to the analysis of the parameters, this treatment should be considered effective.

Effects of athletic tape on orofacial pain and jaw movements after 24 hours of use: a randomized clinical trial.

To analyze the sensation of pain and the range of mandibular movements of adult individuals with temporomandibular disorder, before and after the application of the athletic tape. This is a double-blind randomized clinical trial, in which 22 adults with temporomandibular disorder participated, randomly allocated into two groups, with group A comprising 10 women and one man (mean age 28.2±8.3 years) and group B comprising nine women and two men (mean age 26.2±3.9 years). Group A was submitted to the application of the athletic tape on the masseter with 40% stretch and the group B to the application of the athletic tape on the masseter without stretching. All participants underwent the application of the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD). Pain threshold assessment was performed using an algometer to apply pressure to measurement points. The measurement of mandibular movements was performed using a caliper. The athletic tape was glued using the I technique, with a fixed point over the insertion and a movable point over the origin of the masseter muscle. Participants remained with the athletic tape for 24 hours and were re-evaluated. There was pain relief in the group A in the temporomandibular joint on the right and at the origin of the masseter on the left. The group B showed a reduction in pain in the left anterior temporal region. No differences were found in mandibular movements after intervention, as well as no difference was found in the comparison by groups. The use of the athletic tape over the masseter muscle, with stretching, for 24 hours produced relief from the sensation of pain, on the origin of the right masseter and in the right temporomandibular joint, and, without stretching, in the left anterior temporal muscle. There was no difference in the range of mandibular movements.

Effects of athletic tape on orofacial pain and jaw movements after 24 hours of use: a randomized clinical trial

Effects of athletic tape on orofacial pain and jaw movements after 24 hours of use: a randomized clinical trial

АНАЛОГОВЫЙ И ЦИФРОВОЙ ПРОТОКОЛЫ ОЦЕНКИ ИЗБИРАТЕЛЬНОГО ПРИШЛИФОВЫВАНИЯ ЗУБНЫХ РЯДОВ С ОККЛЮЗИОННЫМИ НАРУШЕНИЯМИ ПЕРЕД ДЕНТАЛЬНОЙ ИМПЛАНТАЦИЕЙ

For successful orthopedic treatment using dental implants, an objective diagnosis of pathological changes in teeth and periodontal tissues is necessary. The identification and optimization of occlusive disorders at various stages of preparation for dental surgery contributes to the normalization of osseointegration processes, expands indications for periodontal diseases. The aim of the study was to assess the normalization of occlusive disorders before dental implantation using analog and digital protocols. The study included 57 patients aged 30 to 65 years and divided into 3 groups: the first group –23 patients with chronic generalized periodontitis of mild severity; the second group–20 patients with nonphysiological location of individual teeth due to partial defects of the dentition; the control group–14 patients. Results. The assessment of occlusive disorders was carried out using occlusography methods and in the articulator "Stratos -300". In the first group–62.6% of supracontacts, in the second group – 49.3%. Occlusive correction of premature contacts was performed. The control was carried out by electronic axiography. Occlusal harmony of occlusal-articulatory relations has been achieved after selective polishing. A comfortable closing of the teeth and smooth movement of the lower jaw have been achieved. The qualitative and quantitative indicators of the axiogram have improved.

Anatomic Characteristics of Ultrasound Imaging of the Temporomandibular Joint at Rest and in Various Jaw Positions in Healthy Individuals: A Descriptive Study

This study examined the temporomandibular joint (TMJ) anatomy and biomechanics using Ultrasound (US) imaging to examine the TMJ anatomy at rest and in various positions of normal jaw movement in healthy individuals. A secondary aim was to describe US imaging parameters used to visually observed the TMJ. The study included 11 participants (8 M and 3 F; 22.9 ± 3.4 yrs) University with no history of TMJ problems. All 11 participants had some atypical anatomy (flat mandibular head, altered articular disc shape, displacement or deformation of the disc during movement) while using US imagining. No participants had current pain or dysfunction and none met the Diagnostic Criteria for Temporomandibular Dysfunction (DC-TMD) classifications for the condition. Most participants denied symptoms during testing, although one participant did have pain with retrusion and another had popping without pain. This study in part has added to the growing interest of using US imaging as modality to investigate the anatomy and biomechanics of the TMJ and the relationship to TMD. Future studies are warranted to examine TMJ anatomy and biomechanics via US imaging in order to provide further recommendations on the techniques and settings for the modality for the end-user.

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.

Simultaneous Maxillomandibular Distraction in Hemifacial Microsomia: A Comprehensive Review and Report of Case

Abstract Hemifacial microsomia (HFM) is a deformity of variable expressivity with unilateral hypoplasia of the mandible and the ear. Treatment of such poses a challenge as both soft and hard tissue deficiencies are to be addressed. The goal is to improve facial symmetry, allow functional jaw movement, obtain stable occlusion, and achieve patient satisfaction. This article discusses about the management of a patient with HFM using simultaneous maxillomandibular distraction also popularly known as the Oritz-Monasterio Molina technique.

Complete mouth rehabilitation, using jaw motion tracking and double scan technique in a patient with osteoarthrosis: a case report

Complete mouth rehabilitation, using jaw motion tracking and double scan technique in a patient with osteoarthrosis: a case report

Wireless Intraoral Jaw Motion Tracker Performance Evaluation and Demonstration of Operation In Vitro and In Vivo

Wireless Intraoral Jaw Motion Tracker Performance Evaluation and Demonstration of Operation In Vitro and In Vivo

Simultaneous Audio Recording and Magnetic Resonance Imaging of the Temporomandibular Joint

Background: Temporomandibular joint disorder is a complex disease requiring multimodal treatment and often a delayed diagnosis. Purpose: The primary objective of this study is to evaluate the feasibility of simultaneously recording joint sounds while obtaining 3-tesla cine-magnetic resonance imaging (3T cine-MRI) of the temporomandibular joint (TMJ). A secondary objective pertains to optimization of a dynamic TMJ imaging protocol to maximize image quality and speed while maintaining synchronicity. Methods: Investigators enrolled four subjects (August 2018 to August 2019) eliciting audible joint sounds during continuous open-close jaw movements during clinical evaluation at the New York University College of Dentistry. A contact fiber-optic microphone (OptiRhythm 4130, Optoacoustics, Yehuda Israel) was utilized to record joint sounds elicited with functional movements during MR dynamic imaging at NYU Langone Health and all data was recorded appropriately. Results: Results of this feasibility study demonstrate the successful integration of audio and 3-Tesla MR imaging for the TMJ in all subjects. This protocol was shown to be well-tolerated by the subjects. A precise correlation of the movement of TMJ structures within cine-MRI images and with audible observations was achieved and assessed by an experienced oral and maxillofacial surgeon and an experienced radiologist. Conclusion: This protocol for simultaneous audio/cine-MRI is a viable tool for studying TMJ health and disease. In future studies, we anticipate this protocol will ultimately refine our understanding of TMJ sounds and their relation to anatomy, physiology, and pathology. In addition, we hope to establish a diagnostic aid to guide surgical and non-surgical decision-making more precisely.

Oral Motor Exercise in Improving the Movements Of The Jaw, Lip, Tongue in Case of Oral Phase Dysphagia on a Cerebral Palsy Patient

The dysphagia case in children with cerebral palsy is a disorder that must be treated immediately because it will have a serious impact on the child's health and speech fluency. The Oral motor exercise method is one of the therapies to improve jaw, neck, and tongue movements in patients with cerebral palsy. The purpose of this study was to investigate the oral motor exercise on a dysphagia patient of 3-years old with cerebral palsy disorder at Syamsudin SH Hospital, Sukabumi, from January to March 2019. This type of research is a descriptive quantitative method with single subject experiment. A research subject was a patient with cerebral palsy, a 3- years old – boy who has dysphagia. The patient cannot speak and only cries and says 'AAAA' if he wanted something and the patient was choking and coughing when eating or drinking. To deal with this problem, 20 sessions of therapy and 1 evaluation were carried out. The results showed that by comparing the results of the initial test and the final test, there was an increase in the ability to move the organs of the lips, tongue, jaw, and chewing movements of the patient. In the initial test, the patient got 2 points and the final test result. the patient got 4 points which indicated 50% success scale. From the therapeutic success scale obtained, it was concluded that the therapy was quite successful.

On the Cranial Nerves.

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.

Investigation on the accuracy of field widths and the quantitative relationship with energy variations for dynamic jaws helical tomotherapy.

TomoEDGE is an advanced technology for TomoTherapy treatment delivery by introducing a sliding-window dynamic jaw motion. The front and back jaws move independently at the start and end of a target volume along the longitudinal couch direction to reduce the undesired dose to the normal tissues. The accuracy of field width is essential to treatment delivery in this regard. The purpose of this work was to analyze the performance of dynamic jaws on helical tomotherapy and investigate the relationship with energy variation. The Tomotherapy-Quality-Assurance (TQA) Dynamic Field Width procedure was performed monthly across three tomotherapy machines. All field widths were analyzed, especially the FWHM of the 10mm field width. Field width measurements were compared with the ratio of Percentage Depth Dose at 20 and 10cm to render the value of correlation. Changes in beam FWHM and energy were further discussed. Two-year data were collected for this purpose. On average, measured field widths in each unit agreed within 1% tolerance recommendation stated. The average absolute difference between reference and measured FWs in each unit was approximately 0.07mm. An increase of 1.5% in the FW of the 10mm nominal beam width was correlated with a 1% increase in PDD20,10 ratio, implying a positive correlation between the two factors (p<0.002). A positive correlation between nominal 10mm FW and PDD20,10 was observed. In the case that the PDD20,10 marginally passes the QA tests, users are recommended to consider further verification on Dynamic Jaws to ensure the smallest field width to be within tolerance, which is essential to maintain effective treatment in TomoEDGE system. Since the regression of this study was a single-factor model, other confounding factors such as the focal spot size of linear accelerator should also be considered when evaluating the machine status.

Hubungan antara kebiasaan parafungsional dan gangguan temporomandibula pada anak usia remaja (Kajian terbatas di Jakarta)

Background: Temporomandibular disorders (TMD) are musculoskeletal disorders involving the temporomandibular joints, masticatory muscles, and associated structures. The etiology of temporomandibular disorders is complex and multifactorial. Parafunctional activities are considered main factors that are associated with TMD. Objective: To examine the association between parafunctional habits and temporomandibular disorders in adolescence. Methods: An analytical observational study with a cross-sectional design was carried out on 443 children (236 men and 207 women) aged 12-13 years. The data obtained consisted of univariate and bivariate data on parafunctional habits and temporomandibular disorders based on the results of the adolescent’s questionnaire V.2. The data were analyzed by Chi-square test. Result: Bivariate analysis showed a significant association (p &lt;0.05) between sleep clenching and awake clenching with temporomandibular pain (p = 0.047 and p = 0.001). A significant association was found between sleep grinding and biting the lips / cheeks habits with joint sounds (click / pop) (p = 0.045 and p = 0.020). Analysis of the association between sleep grinding and sleep clenching with limited jaw motion also showed a significant association (p = 0.014 and p = 0.004). Conclusion: There are associations between clenching and temporomandibular pain; sleep grinding and biting the lips / cheeks with joint sounds (click / pop); and between sleep bruxism and limited jaw motion.

Acute Effects of Brevetoxin-3 Administered via Oral Gavage to Mice.

Brevetoxins (BTXs) constitute a family of lipid-soluble toxic cyclic polyethers mainly produced by Karenia brevis, which is the main vector for a foodborne syndrome known as neurotoxic shellfish poisoning (NSP) in humans. To prevent health risks associated with the consumption of contaminated shellfish in France, the French Agency for Food, Environmental and Occupational Health & Safety (ANSES) recommended assessing the effects of BTXs via an acute oral toxicity study in rodents. Here, we investigated the effect of a single oral administration in both male and female mice with several doses of BTX-3 (100 to 1,500 µg kg-1 bw) during a 48 h observation period in order to provide toxicity data to be used as a starting point for establishing an acute oral reference dose (ARfD). We monitored biological parameters and observed symptomatology, revealing different effects of this toxin depending on the sex. Females were more sensitive than males to the impact of BTX-3 at the lowest doses on weight loss. For both males and females, BTX-3 induced a rapid, transient and dose-dependent decrease in body temperature, and a transient dose-dependent reduced muscle activity. Males were more sensitive to BTX-3 than females with more frequent observations of failures in the grip test, convulsive jaw movements, and tremors. BTX-3's impacts on symptomatology were rapid, appearing during the 2 h after administration, and were transient, disappearing 24 h after administration. The highest dose of BTX-3 administered in this study, 1,500 µg kg-1 bw, was more toxic to males, leading to the euthanasia of three out of five males only 4 h after administration. BTX-3 had no effect on water intake, and affected neither the plasma chemistry parameters nor the organs' weight. We identified potential points of departure that could be used to establish an ARfD (decrease in body weight, body temperature, and muscle activity).

Application of 3D digital smile design based on virtual articulation analysis in esthetic dentistry: A technique

A technique for the application of a virtual articulation system in 3-dimensional digital smile design (DSD) during esthetic restoration is described. To acquire stable occlusion and a smooth jaw movement pattern without premature contacts or interference, a digital facebow and a virtual articulator were used to collect and analyze a patient’s occlusal data and jaw movement information. The original pattern of occlusal contacts and jaw movements were diagnosed as stable and copied to the digital design of the new prostheses. Preparation of the abutments, crown lengthening surgery, and definitive crown fabrication and cementation were performed according to the design. After 9 months, the occlusion remained stable, and the patient was satisfied with the outcome.

Prevalence of temporomandibular disorders in clear aligner patients using orthodontic intermaxillary elastics assessed with diagnostic criteria for temporomandibular disorders (DC/TMD) axis II evaluation: A cross-sectional study.

The objective of this investigation is to assess the relationship between the utilisation of orthodontic intermaxillary elastics and temporomandibular disorder (TMD) symptoms in clear aligner patients and to examine the correlation between the elastic usage time with the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD)-Axis II Evaluation Forms. This study was carried out on a total of 40 clear aligner patients using intermaxillary elastics in the experimental group and 30 clear aligner patients who did not use any intermaxillary elastics in the control group. The data were evaluated using the Mann-Whitney U, chi-square, Fisher's exact chi-square, and Fisher Freeman Halton exact chi-square tests. The characteristic pain intensity, mastication, mobility, communication, global and PHQ-9 scores of the experimental group were significantly higher than those of the control group (p < .05). The characteristic pain intensity score, interference score and chronic pain grade score of patients using Class III elastics were statistically significantly higher than those of patients using Class II elastics (p < .05). Patients who used elastics for less than 6 months had statistically significantly higher PHQ-9 scores than those who used elastics for more than 6 months (p < .05). Orthodontic treatment may affect occlusion, bite force and jaw movement, which may cause or worsen TMD symptoms, and the DC/TMD questionnaires can determine if orthodontic patients acquire TMD by assessing their psychosocial state and pain-related problems.

Rat Model of Aerodigestive Dysfunction in Alzheimer’s Disease

AbstractBackgroundOral nutrition and aspiration pneumonia are significant factors impacting survival in patients with Alzheimer’s disease and related dementias (ADRD). Patients with ADRD demonstrate impairments to critical aerodigestive functions, including: prolonged oral phase durations, impaired masticatory performance, and prolonged swallow apnea durations. However, the pathophysiology underlying these functional changes is poorly understood. Establishing a translational model of swallowing dysfunction in ADRD will be critical for identifying underlying mechanisms of aerodigestive dysfunction and optimizing clinical treatments.MethodsAdult male TgF344‐AD rats (n = 6) and wild type rats (WT; n = 6) underwent videofluoroscopy (60 fps) to assess swallowing kinematics at 12 months of age. Jaw movement, bolus position, and diaphragm movement (proxy for respiration) were analyzed off‐line. All rats underwent a hypoglossal nerve electrical stimulation protocol, with the protruded tongue attached via small suture to a force transducer. All rats were stimulated maximally at a range of frequencies from 1 Hz – 140 Hz.ResultsThe AD group had significantly slower mastication rates (p = .037) and prolonged swallow apnea durations (p = .017) compared to WT. The AD group produced significantly lower forces at 60 Hz (p&lt;.001) and 80 Hz (p&lt;.001), indicating a higher frequency of nerve stimulation was required to elicit a given force of isometric tongue muscle contraction.ConclusionThe TgF344‐AD rat demonstrates functional mastication and swallowing decline consistent with clinical findings in patients with ADRD, with concomitant alterations in tongue muscle contractile properties and can serve as a valuable tool for interrogating biological and physiological mechanisms of aerodigestive dysfunction.

Marcus Gunn jaw-winking syndrome: A case report

Abstract Marcus Gunn jaw wink phenomenon or Trigeminal oculomotor synkinesis, is a congenital disorder in which the upper lid moves synkinetically in response to jaw movement during chewing. The term synkinesis describes the simultaneous movement or a coordinated sequence of movements of muscles, which are supplied by different nerves or by separate peripheral branches of the same nerve. Although it rarely manifests bilaterally, it is typically unilateral. In 1883, Dr Robert Marcus Gunn, a Scottish Ophthalmologist described a 15-year-old girl with a peculiar type of congenital ptosis that included an associated winking motion of the affected eyelid on the movement of the jaw. It is known to affect both men and women equally. This phenomenon has been reported to be a similar phenomenon affecting 2-13% of all cases of congenital ptosis. It can be congenital or acquired, for example through trauma. The Congenital Marcus Gunn jaw wink phenomenon is thought to arise from the connection between the branch of the trigeminal nerve (responsible for chewing) supplying the middle or lateral pterygoid muscle and the branch of the oculomotor nerve supplying the upper superior levator ocular defect. Here we present a case report of Marcus Gunn’s Jaw-Winking Synkinesis in congenital ptosis.