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Unravelling the Complexities of Bite Force Determinants in Paediatric Patients: A Literature Review.Cureus May 2024The amount of maximum voluntary bite force (MVBF) is determined by the combined action of the jaw elevator muscles, which are altered jaw biomechanics and reflex... (Review)
Review
The amount of maximum voluntary bite force (MVBF) is determined by the combined action of the jaw elevator muscles, which are altered jaw biomechanics and reflex processes. Bite force (BF) measurements can yield valuable information on the activity and function of the jaw muscles. The accuracy of biting force measurements depends on several variables, including age, gender, malocclusion, dental caries, dental prostheses and temporomandibular joint (TMJ). This information is essential for evaluating the development and function of the masticatory system, identifying potential abnormalities or impairments and guiding appropriate treatment interventions for paediatric patients. The aim of this article is to review the literature on the factors affecting bite force and the importance of these factors in assessing dental development and guiding interventions for paediatric patients with bite force-related issues. Additionally, establishing normative values for bite force in different age groups can aid in monitoring growth and detecting any deviations from expected patterns. Measuring bite force in paediatric patients is significant in comprehensive oral health assessment and management.
PubMed: 38903313
DOI: 10.7759/cureus.60630 -
Drugs Jun 2024Temporomandibular disorders (TMDs) encompass several conditions that cause pain and impair function of the masticatory muscles (M-TMDs) and temporomandibular joints....
OBJECTIVE
Temporomandibular disorders (TMDs) encompass several conditions that cause pain and impair function of the masticatory muscles (M-TMDs) and temporomandibular joints. There is a large interest among clinicians and researchers in the use of botulinum toxin-A (BoNT-A) as a treatment for M-TMD. However, due to the lack of consistent evidence regarding the efficacy as well as adverse events of BoNT-A, clinical decision making is challenging. Therefore, this umbrella review aimed to systematically assess systematic reviews (SRs) evaluating BoNT-A treatment effects on pain intensity, mandibular movements, and adverse events in patients with M-TMDs.
METHOD
An electronic search was undertaken in the databases MEDLINE, EMBASE, CINAHL, Cochrane Central Registry of Controlled Trials (CENTRAL), Web of Science, Epistemonikos, ClinicalTrials.gov, and ICTRP to identify SRs investigating BoNT-A effects on M-TMDs, published from the inception of each database until 6 December 2023. The quality of evidence was rated according to the critical appraisal checklist developed by the umbrella review methodology working group. Only high-quality SRs were included.
RESULTS
In total, 18 SRs were included. BoNT-A was shown to be more effective than placebo to reduce pain intensity, but not compared to standard treatments. Additionally, BoNT-A was not superior to placebo or standard treatments regarding improvement of mandibular movements. BoNT-A was considered to have a higher risk for adverse events on muscle and bony tissue compared with other treatments.
CONCLUSION
The synthesis in this umbrella review provides the highest level of evidence present. Taken together, there are indications of effectiveness of BoNT-A for treatment of M-TMDs, supported by moderate evidence. However, considering the risk of causing serious adverse events, treatment with BoNT-A is recommended to be the last treatment alternative.
PubMed: 38900335
DOI: 10.1007/s40265-024-02048-x -
Journal of Oral Rehabilitation Jun 2024Activation of β adrenergic receptors reduces cutaneous mechanical pain thresholds in rats. While β adrenergic receptor activation may contribute to mechanisms that...
BACKGROUND
Activation of β adrenergic receptors reduces cutaneous mechanical pain thresholds in rats. While β adrenergic receptor activation may contribute to mechanisms that underlie temporomandibular joint pain, its effect on masticatory muscle pain sensitivity is uncertain.
OBJECTIVES
The current study sought to determine the extent to which β adrenergic receptors are expressed by masticatory muscle afferent fibres, and to assess the effect of local activation of these receptors on the mechanical sensitivity of masticatory muscle afferent fibres in rats.
METHODS
Trigeminal ganglion neurons that innervate the rat (n = 12) masseter muscle and lower lip were identified by tissue injection of fluorescent dyes and were then stained with antibodies against β or β adrenergic receptors. Extracellular recordings from 60 trigeminal ganglion neurons that innervate the masticatory muscle were undertaken in a second group of anaesthetised rats of both sexes (n = 37) to assess afferent mechanical activation thresholds. Thresholds were assessed before and after injection of the β adrenergic receptor agonists into masticatory muscle.
RESULTS
β and β adrenergic receptor expression was greater in labial skin than in masticatory muscle ganglion neurons (p < .05, one-way ANOVA, Holm-Sidak test). There was a higher expression of β adrenergic receptors in masticatory muscle ganglion neurons in males than in females. The mixed β agonist isoproterenol increased afferent mechanical activation threshold in male but not female rats (p < .05, Mann-Whitney test). In male rats, salbutamol, a β selective agonist, also increased afferent mechanical activation threshold but hydralazine, a vasodilator, did not (p < .05, Mann-Whitney test).
CONCLUSION
Activation of β adrenergic receptors decreases the mechanical sensitivity of masticatory muscle afferent fibres in a sex-related manner.
PubMed: 38894554
DOI: 10.1111/joor.13787 -
Journal of Clinical Medicine May 2024Temporomandibular disease (TMD) is commonly seen, and divers also experience pain in the temporomandibular joint (TMJ) or masticatory muscles. This article aims to...
Temporomandibular disease (TMD) is commonly seen, and divers also experience pain in the temporomandibular joint (TMJ) or masticatory muscles. This article aims to provide a tool for diving physicians or medical professionals involved in diving medicine since jaw pain among divers is a pertinent subject and can be challenging to evaluate without some background in dentistry or maxillofacial surgery. A basic algorithm was developed to provide a tool to differentiate jaw pains experienced by divers. Three brief case studies were developed, and five diving physicians were tasked with diagnosing the cases using the algorithm. Additionally, simple exercises and massage techniques that can benefit patients with TMD, particularly immediately after diving, are outlined. All five diving physicians successfully diagnosed the cases using the algorithm. However, three of them were unable to diagnose the first case (disc luxation) without consulting the algorithm. Nevertheless, all physicians acknowledged the utility of the algorithm. Jaw pain in divers can stem from diverse causes, but effective treatment options exist. Our study findings provide valuable insights to assist diving physicians in making accurate diagnoses and guiding appropriate patient management, which may include referrals to specialists such as dentists, maxillofacial surgeons, or orthodontists.
PubMed: 38892877
DOI: 10.3390/jcm13113167 -
Cells Jun 2024Temporomandibular disorders (TMDs) are a heterogeneous group of musculoskeletal and neuromuscular conditions involving the temporomandibular joint (TMJ), masticatory... (Review)
Review
Temporomandibular disorders (TMDs) are a heterogeneous group of musculoskeletal and neuromuscular conditions involving the temporomandibular joint (TMJ), masticatory muscles, and associated structures. Mesenchymal stromal/stem cells (MSCs) have emerged as a promising therapy for TMJ repair. This systematic review aims to consolidate findings from the preclinical animal studies evaluating MSC-based therapies, including MSCs, their secretome, and extracellular vesicles (EVs), for the treatment of TMJ cartilage/osteochondral defects and osteoarthritis (OA). Following the PRISMA guidelines, PubMed, Embase, Scopus, and Cochrane Library databases were searched for relevant studies. A total of 23 studies involving 125 , 149 , 470 , and 74 were identified. Compliance with the ARRIVE guidelines was evaluated for quality assessment, while the SYRCLE risk of bias tool was used to assess the risk of bias for the studies. Generally, MSC-based therapies demonstrated efficacy in TMJ repair across animal models of TMJ defects and OA. In most studies, animals treated with MSCs, their derived secretome, or EVs displayed improved morphological, histological, molecular, and behavioral pain outcomes, coupled with positive effects on cellular proliferation, migration, and matrix synthesis, as well as immunomodulation. However, unclear risk in bias and incomplete reporting highlight the need for standardized outcome measurements and reporting in future investigations.
Topics: Animals; Temporomandibular Joint; Mesenchymal Stem Cells; Mesenchymal Stem Cell Transplantation; Temporomandibular Joint Disorders; Humans; Osteoarthritis; Extracellular Vesicles; Disease Models, Animal
PubMed: 38891122
DOI: 10.3390/cells13110990 -
Proceedings. Biological Sciences Jun 2024The morphology and biomechanics of infant crania undergo significant changes between the pre- and post-weaning phases due to increasing loading of the masticatory...
The morphology and biomechanics of infant crania undergo significant changes between the pre- and post-weaning phases due to increasing loading of the masticatory system. The aims of this study were to characterize the changes in muscle forces, bite forces and the pattern of mechanical strain and stress arising from the aforementioned forces across crania in the first 48 months of life using imaging and finite element methods. A total of 51 head computed tomography scans of normal individuals were collected and analysed from a larger database of 217 individuals. The estimated mean muscle forces of temporalis, masseter and medial pterygoid increase from 30.9 to 87.0 N, 25.6 to 69.6 N and 23.1 to 58.9 N, respectively (0-48 months). Maximum bite force increases from 90.5 to 184.2 N (3-48 months). There is a change in the pattern of strain and stress from the calvaria to the face during postnatal development. Overall, this study highlights the changes in the mechanics of the craniofacial system during normal development. It further raises questions as to how and what level of changes in the mechanical forces during the development can alter the morphology of the craniofacial system.
Topics: Infant; Humans; Bite Force; Biomechanical Phenomena; Skull; Child, Preschool; Tomography, X-Ray Computed; Finite Element Analysis; Female; Male; Mastication; Adaptation, Physiological; Infant, Newborn; Stress, Mechanical; Masticatory Muscles
PubMed: 38889789
DOI: 10.1098/rspb.2024.0654 -
Scientific Reports Jun 2024Temporal muscle thickness measured on 3D MRI has recently been linked to prognosis in glioblastoma patients and may serve as an independent prognostic indicator. This...
Temporal muscle thickness measured on 3D MRI has recently been linked to prognosis in glioblastoma patients and may serve as an independent prognostic indicator. This single-center study looked at temporal muscle thickness and prognosis in patients with primary glioblastoma. Overall survival was the major study outcome. For a retrospective analysis from 2010 to 2020, clinical data from 102 patients with glioblastoma at the Department of Oncology Radiotherapy of the First Affiliated Hospital of Dalian Medical University were gathered. Fifty-five cases from 2016 to 2020 contained glioblastoma molecular typing data, of which 45 were IDH wild-type glioblastomas and were analysed separately. TMT was measured on enhanced T1-weighted magnetic resonance images in patients with newly diagnosed glioblastoma.Overall patient survival (OS) was calculated by the Kaplan-Meier method and survival curves were plotted using the log-rank-sum test to determine differences between groups, and multifactorial analyses were performed using a Cox proportional-risk model.The median TMT for 102 patients was 6.775 mm (range: 4.95-10.45 mm). Patients were grouped according to median TMT, and the median overall survival (23.0 months) was significantly longer in the TMT > median group than in the TMT median group (P 0.001; Log-rank test). Analysing 45 patients with IDH wild type alone, the median overall survival (12 months) of patients in the TMT > median group was significantly longer than that of patients in the TMT ≤ median group (8 months) (P < 0.001; Log-rank test).TMT can serve as an independent prognostic factor for glioblastoma.
Topics: Humans; Glioblastoma; Male; Female; Middle Aged; Prognosis; Temporal Muscle; Adult; Aged; Brain Neoplasms; Retrospective Studies; Magnetic Resonance Imaging; Kaplan-Meier Estimate; Isocitrate Dehydrogenase; Young Adult
PubMed: 38886495
DOI: 10.1038/s41598-024-64947-z -
Journal of Visualized Experiments : JoVE May 2024Craniofacial volumetric muscle loss (VML) injuries can occur as a result of severe trauma, surgical excision, inflammation, and congenital or other acquired conditions....
Craniofacial volumetric muscle loss (VML) injuries can occur as a result of severe trauma, surgical excision, inflammation, and congenital or other acquired conditions. Treatment of craniofacial VML involves surgical, functional muscle transfer. However, these procedures are unable to restore normal function, sensation, or expression, and more commonly, these conditions go untreated. Very little research has been conducted on skeletal muscle regeneration in animal models of craniofacial VML. This manuscript describes a rat model for the study of craniofacial VML injury and a protocol for the histological evaluation of biomaterials in the treatment of these injuries. Liquid hydrogel and freeze-dried scaffolds are applied at the time of surgical VML creation, and masseters are excised at terminal time points up to 12 weeks with high retention rates and negligible complications. Hematoxylin and eosin (HE), Masson's Trichrome, and immunohistochemical analysis are used to evaluate parameters of skeletal muscle regeneration as well as biocompatibility and immunomodulation. While we demonstrate the study of a hyaluronic-acid-based hydrogel, this model provides a means for evaluating subsequent iterations of materials in VML injuries.
Topics: Animals; Rats; Masseter Muscle; Hydrogels; Disease Models, Animal; Biocompatible Materials; Tissue Scaffolds; Regeneration; Rats, Sprague-Dawley; Bioengineering; Hyaluronic Acid; Male
PubMed: 38884461
DOI: 10.3791/66450 -
Dental Clinics of North America Jul 2024Mandibular advancement devices (MADs) keep the upper airways patent by holding the mandible and attached soft tissues forward via altered position of its condyles...
Mandibular advancement devices (MADs) keep the upper airways patent by holding the mandible and attached soft tissues forward via altered position of its condyles relative to the articulating surfaces of the temporal bones. During the first weeks of MAD therapy, pain may occur in the area of the temporomandibular joints, masticatory muscles, and/or teeth with a tendency of spontaneous resolution. In patients reporting temporomandibular disorder (TMD) symptoms prior to therapy, the MAD-related anterior condylar position during sleep may result in a reduction of TMD signs and symptoms.
Topics: Humans; Facial Pain; Mandibular Advancement; Mandibular Condyle; Sleep Apnea, Obstructive; Temporomandibular Joint Disorders
PubMed: 38879285
DOI: 10.1016/j.cden.2024.02.003 -
Computers in Biology and Medicine Jun 2024Alterations in occlusal features may have significant consequences, ranging from dental aesthetics to health issues. Temporomandibular joint disorders (TMDs) are often...
Alterations in occlusal features may have significant consequences, ranging from dental aesthetics to health issues. Temporomandibular joint disorders (TMDs) are often associated with joint overload, and the correlation between occlusal features and TMDs has been thoroughly discussed. In current work, we introduced a novel stomatognathic model that aligns well with in vivo experimental measurements, specifically designed to decouple the impact of occlusal contact and periodontal ligament (PDL) negative feedback on temporomandibular joint (TMJ) loading. Utilizing an in-silico approach, the simulation analysis included six symmetric occlusal contact scenarios. Furthermore, a biomechanical lever model was employed to clarify the mechanical mechanism and investigate the multi-factorial effects of TMJ overload. These findings indicate that anterior shifts in the occlusal centre lead to increased TMJ loading, particularly in occlusal contact cases with anteroposterior changes. Considering the symmetrical distribution of occlusal contact, mediolateral alterations had a more modest effect on TMJ loading. Additionally, potential negative feedback activated by principal strain of periodontal could not only alleviate joint load but also diminish occlusal force. These investigations enhance our understanding of the intricate interactions between masticatory muscles, occlusal forces, and joint contact forces, thereby providing motivation for future comprehensive studies on TMJ biomechanical overload.
PubMed: 38878405
DOI: 10.1016/j.compbiomed.2024.108725