Search Results (116)

Background: Temporomandibular disorders are a generic term referred to clinical conditions involving the jaw muscles and temporomandibular joint with multifactorial pattern and genetic background. The aim of this observational study was to investigate the correlation between craniomandibular disorders and the presence of occlusal alterations. A clinical evaluation of the occlusal and articular status of the patients was carried out, integrating the latter with the electromyographic recording the activity of the masseter and temporalis muscles. Methods: A clinical observational study on 20 adults assessed temporomandibular disorders using DC/TMD criteria, anamnesis, clinical exams, occlusal and electromyographic analyses. Occlusion was evaluated morphologically and functionally. Electromyography tested static/dynamic muscle activity. Data were statistically analyzed using t-tests and Pearson correlation (p < 0.05). Results: Electromyographic analysis revealed significant differences between subjects with and without visual correction, suggesting that visual input influences masticatory muscle activity. Correlations emerged between occlusal asymmetries and neuromuscular parameters. These findings highlight clinical implications for mandibular function, muscle symmetry, and the potential for therapeutic rebalancing through targeted interventions. Conclusions: The study demonstrates a significant correlation between visual–motor integration and masticatory muscle efficiency. It emphasizes lateralized neuromuscular activation’s influence on occlusal contact distribution. Moreover, it identifies mandibular torsion–endfeel inverse correlation as a potential diagnostic marker for craniomandibular dysfunctions via surface electromyography. Full article

Background/Objectives: Tension-type headache (TTH) is the most prevalent form of primary headache. The etiology of TTH is not yet fully understood, although it is associated with the presence of myofascial trigger points (MTPs) in cervical and facial muscles. Dry needling (DN) therapy has emerged as an effective and safe non-pharmacological option for pain relief, but there are a lack of systematic reviews focused on its specific characteristics in TTH. The aim of this paper is to examine the characteristics and methodologies of DN in managing TTH. Methods: A scoping review was conducted with inclusion criteria considering studies that evaluated DN interventions in adults with TTH, reporting target muscles, diagnostic criteria, and technical features. The search was performed using PubMed, Embase, Scopus, and the Web of Science, resulting in the selection of seven studies after a rigorous filtering and evaluation process. Results: The included studies, primarily randomized controlled trials, involved a total of 309 participants. The most frequently treated muscles were the temporalis and trapezius. Identification of MTPs was mainly performed through manual palpation, although diagnostic criteria varied. DN interventions differed in technique. All studies included indicated favorable outcomes with improvements in headache symptoms. No serious adverse effects were reported, suggesting that the technique is safe. However, heterogeneity in protocols and diagnostic criteria limits the comparability of results. Conclusions: The evidence supports the use of DN in key muscles such as the temporalis and trapezius for managing TTH, although the diversity in methodologies and diagnostic criteria highlights the need for standardization. The safety profile of the method is favorable, but further research is necessary to define optimal protocols and improve reproducibility. Implementing objective diagnostic criteria and uniform protocols will facilitate advances in clinical practice and future research, ultimately optimizing outcomes for patients with TTH. Full article

Background/Objectives: Bruxism has been associated with dysregulation of the autonomic nervous system (ANS). Visceral manual therapy (VMT) has shown beneficial effects on the vagal tone and modulation of ANS activity. This study aimed to evaluate the immediate and short-term effects of VMT in individuals with clinically based bruxism. Methods: A single-blind randomized controlled trial was conducted including 24 individuals with clinically based bruxism. Participants received two sessions of either VMT or a sham placebo technique. Outcome measures included heart rate variability (HRV), both normal-to-normal intervals (HRV-SDNN), and the root mean square of successive normal-to-normal intervals (HRV-RMSSD), as well as muscle tone and stiffness and pressure pain thresholds (PPTs). Measurements were made at T1 (baseline), T2 (post-first intervention), T3 (pre-second intervention), T4 (post-second intervention), and T5 (4-week follow-up). Results: A significant time*group interaction was observed for HRV-SDNN (p = 0.04, η² = 0.12). No significant changes were found for muscle tone or stiffness. PPTs significantly increased at C4 after the second session (p = 0.049, η² = 0.16) and at the left temporalis muscle after the first session (p = 0.01, η² = 0.07). Conclusions: The findings suggest that two sessions of VMT may lead to significant improvements in HRV-SDNN compared to the placebo, suggesting a modulatory effect on autonomic function. No consistent changes were observed for the viscoelastic properties of the masticatory muscles. Isolated improvements in pressure pain sensitivity were found at C4 and the left temporalis muscle. Further research with larger sample sizes and long-term follow-up is needed to determine the clinical relevance of VMT in the management of signs and symptoms in individuals with bruxism. Full article

Background: The occlusal angle (OA), influenced by pillow height, may affect muscle tension in the head and neck. However, its optimal range for minimizing muscle activation has not been clearly defined. Objective: This study aimed to investigate the effects of OA on the resting muscle activity of masticatory and cervical muscles and to identify an optimal OA range using cluster analysis and linear mixed-effects modeling. Methods: The resting muscle activities of the masseter (MAS), temporalis (TEM), sternocleidomastoid (SCM), and posterior vertebral muscles (PVM) were measured at OA conditions modulated by pillow heights of 0, 5, and 10 cm at 0, 1, and 5 min in the supine position. Intraclass correlation coefficients (ICCs) assessed measurement reliability. Statistical analyses included ANOVA, ROC curve analysis, k-means clustering, and linear mixed-effects models. Results: MAS and TEM resting muscle activity ratio (RMR) significantly increased with larger OA values (p < 0.001), while SCM showed decreased activation (p = 0.001). An OA range of 105°–111° was identified as the center of a low-activity cluster, and an upper cut-off of 138° was associated with potential muscular overload. ICC values for MAS and SCM ranged from 0.82 to 0.89, indicating excellent test–retest reliability. Conclusions: OA modulated by pillow height is a modifiable factor that influences muscle activity. An OA of 105°–111° may serve as a practical comfort zone, especially for individuals at risk of TMDs. Full article

Background/Objectives: Variations in the course of the maxillary artery (MA) relative to the lateral pterygoid muscle (LPM) pose critical challenges in surgical, anesthetic, and interventional procedures involving the infratemporal fossa (ITF). These variations can increase the risk of hemorrhage, nerve injury, or incomplete anesthesia. The present study aimed to elucidate the topographic relationship between the MA and LPM by combining high-resolution radiological imaging with a comprehensive analysis of anatomical literature. Materials and Methods: A retrospective review of 250 brain computed tomography angiographies (CTAs), totaling 500 sides, was conducted to classify the MA course as lateral (superficial), medial (deep), or intramuscular. Additionally, a systematic review and meta-analysis of 32 eligible studies—including 5938 arteries—was performed following PRISMA 2020 and Evidence-Based Anatomy (EBA) guidelines. Study quality and risk of bias were assessed using the Anatomical Quality Assurance (AQUA) tool. Results: In the imaging cohort, the MA coursed lateral to the LPM in 64.2% of sides, medial in 29.6%, and through the muscle fibers in 6.2%. A rare temporalis-traversing variant was identified in 3.0% of cases. Bilateral symmetry was observed in 77.6% of patients. Meta-analytic findings indicated a pooled prevalence of 79.6% for the lateral course, 19.9% for the medial course, and 0.01% for the intramuscular course. Cadaveric studies and Asian populations showed a higher incidence of lateral variants, while imaging-based studies more frequently detected medial and transmuscular paths. Conclusions: While the MA most often follows a lateral course relative to the LPM, clinically significant variation—including medial, intramuscular, and temporalis-traversing routes—exists. These variants complicate access during maxillofacial surgery, TMJ procedures, and regional anesthesia. Findings emphasize the importance of individualized preoperative vascular mapping to improve procedural safety and outcomes in the ITF. Full article

Background/Objectives: Chronic stress has an undeniable effect in generating emotional disorders and physiological changes. It results in excessive muscle tension throughout the body, also in the masticatory system. A situation of chronic stress was the COVID-19 pandemic. The aim of this paper was to assess the prevalence of specific masticatory pain symptoms, their severity, and the co-occurrence of associated symptoms (otological symptoms and headaches) in patients diagnosed before and during the COVID-19 pandemic. Methods: A total of 202 patients were divided into two groups: Group A (mean age of 36.46; F = 64; and M = 37) and B (mean age of 26.04; F = 70; and M = 31) included patients who presented for the study before and after the COVID-19 pandemic, respectively. The Oral Behaviours Checklist (OBC) questionnaire was used: patients with result ≥2 scores in the OBC were evaluated by DC/TMD. To evaluate the intensity of pain in masticatory structures, the elements of the RDC-TMD questionnaire were used. Otologic symptoms and headaches were assessed as coexisted complaints. Results: A significant increase in pain occurrence was observed in Group B mainly for masseter muscles (p < 0.0001), temporalis (p = 0.0044), and medial pterygoid muscles (p = 0.0153). A significantly more frequent reporting of pain/tenderness was observed among men in most of the evaluated muscles. For the lateral pterygoid muscles, changes in palpation pain did not reach statistical significance. There was a statistically significant difference in the intensity of pain in the temporomandibular joint area between both the entire groups A and B (p = 0.000152), as well as between women in Group A and B (p = 0.006453) and men in the study groups (p = 0.007990). An increase in the incidence of headaches was observed among men in Group B (Group A with 40.6% vs. Group B with 67.3%). The most commonly reported otological symptom in both groups was ear pain and/or discomfort in the preauricular region, with the frequency of otological symptoms being higher in Group B. Conclusions: (1) The COVID-19 pandemic affected the incidence and severity of masticatory muscle pain and associated complaints. (2) A decrease in the age of patients reporting complaints of masticatory mm pain was observed during the COVID-19 pandemic. (3) An increase in the frequency of headaches was observed in the male group during the pan-demic, while in women there was an increase in palpation tenderness of masticatory muscles. Full article

Stomatognathic dysfunctions, particularly bruxism, orofacial pain, and temporomandibular joint (TMJ) disorders, are frequently associated with anxiety and depression. However, the reverse hypothesis that these dysfunctions may act as peripheral stressors contributing to neuropsychological imbalance by activating the hypothalamic–pituitary–adrenal (HPA) axis remains underexplored. Objective: To assess the relationship between the severity of stomatognathic symptoms and both physiological and psychological stress markers to determine whether such dysfunctions may influence or exacerbate anxiety and depressive disorders. Methods: A cross-sectional observational study was conducted on 120 adult patients. Clinical assessment was included evaluation of TMJ function, bruxism, and orofacial pain. Psychological screening was performed using validated questionnaires (GAD-7 for anxiety and PHQ-9 for depression). Electromyographic (EMG) analysis of the masseter and temporalis muscles was conducted, along with the quantification of salivary cortisol using an enzyme-linked immunosorbent assay (ELISA). Multiple regression models were applied to identify statistically significant correlations (p < 0.05). Results: A positive correlation was found between the severity of stomatognathic dysfunction and scores on anxiety and depression measures, along with elevated salivary cortisol levels and increased masticatory muscle activity. Conclusions: These findings suggest a bidirectional relationship between stomatognathic dysfunctions and neuropsychological status, underscoring the potential value of integrated therapeutic approaches that combine dental care with psychological support. Full article

Background/Objectives: Studying the second exteroceptive suppression period (ES2) of the temporalis muscle may well shed some light on the brainstem neural circuits involved in migraine pathophysiology. It is known that allodynia is related to an increased sensitization of second-/third-order neurons both in the trigeminal nucleus caudalis and sensory thalamus. This pilot, observational study was carried out in the interictal period on female migraineurs with/without allodynia to assess the ES2 of the temporalis muscle compared to controls. Methods: Forty-nine non-consecutive female patients were enrolled, as they met the diagnostic criteria for migraine (26 episodic and 23 chronic), alongside 23 healthy controls. The inclusion criteria encompassed no ongoing pharmacological prophylactic treatment, and the exclusion criteria included any relevant comorbidities. In line with international standards, the exteroceptive suppression of the temporalis muscle activity was registered on the left side, assessing ES2 latency and duration in the interictal period. Results: Allodynia was observed in 24 patients (50%), and 16/24 (67%) were chronic migraineurs. No statistically significant differences in ES2 latency or its duration between the migraine patients and controls were detected. However, there was a significantly longer ES2 duration in allodynic migraineurs than in the controls (p = 0.04; effect size: 0.71) and in allodynic compared to non-allodynic migraineurs (p = 0.04; effect size: 0.63). Conclusions: The increased duration of ES2 observed in allodynic migraineurs might be related to the impaired activity of brainstem circuits and, in our opinion, it seems reasonable to hypothesize that this change may be a neurophysiological correlate of central sensitization in migraine allodynic patients. Full article

(1) Background: A sedentary lifestyle may aggravate temporomandibular disorder (TMD) symptoms, increasing pain sensitivity and functional limitations. Physical exercise is recommended for pain management and improving quality of life. Comparing CrossFit^® athletes to sedentary individuals allows for examining whether regular high-intensity exercise impacts pain sensitivity and functional limitations associated with TMD. This cross-sectional study assessed the signs and symptoms of TMD in CrossFit^® athletes compared to sedentary individuals. (2) Methods: Participants (n = 121) were divided into four groups: sedentary with TMD (n = 39), sedentary without TMD (n = 37), CrossFit^® athletes with TMD (n = 23), and CrossFit^® athletes without TMD (n = 22). TMD signs and symptoms were evaluated using the Research Diagnostic Criteria for TMD (RDC/TMD) axis I, including mandibular movement patterns, range of motion, joint sounds, muscle pain, and jaw dysfunctions. Statistical analyses included chi-square and Dunn’s post hoc tests, ANOVA, and Kruskal–Wallis tests. Correlation and regression analyses were performed to examine associations between CrossFit^® practice and TMD (p ≤ 0.05). (3) Results: Myofascial pain was the most common diagnosis. All athlete groups exhibited greater mandibular movement amplitudes (unassisted opening without pain, p < 0.001, and protrusion, p = 0.039) and less pain (p < 0.001) than sedentary individuals. Pain reports and palpation-induced pain in muscles and joints were significantly associated with a sedentary lifestyle and TMD (p < 0.001). Joint and muscle pain were more prevalent (frequent) among sedentary participants, regardless of TMD diagnosis. Linear regression analysis showed that sedentary individuals without TMD had significantly reduced unassisted mouth opening amplitudes compared to athletes without TMD (p < 0.05). (4) Conclusions: Pain in the masseter, temporalis, posterior digastric, and medial pterygoid muscles was the most common symptom in sedentary individuals with TMD. They experience higher frequency and intensity of pain, as well as greater limitations in mouth movement. Athletes showed higher frequency of joint noises. Full article

Temporal hollowing, which is a depression in the temple region, often results from trauma, surgical interventions, or neurological conditions. This condition is frequently observed after the resection of encephaloceles, where it can cause esthetic and functional challenges due to temporalis muscle atrophy and nerve palsy. We present a case of a 21-year-old female patient who developed temporal hollowing and complete atrophy of the right temporalis muscle following an encephalocele resection in childhood. The patient also suffered from right-sided frontal nerve branch palsy. To address this complex deformity, a patient-specific implant (PSI) made of hydroxyapatite (HA) was digitally designed and produced using 3D printing technology. The postoperative course was uneventful, with the implant securely positioned and the esthetic result highly satisfactory. This case highlights the potential of 3D printed PSIs in craniofacial reconstruction, offering an optimal solution for both functional restoration and esthetic enhancement. HA further ensures the long-term stability and integration of the implant, providing a promising approach for addressing complex craniofacial defects. Full article

A novel electromyography (EMG)-based wheelchair interface was developed that uses contractions from the temporalis muscle to control a wheelchair. To aid in the training process for users of this interface, a serious training game, Limbitless Journey, was developed to support patients. Amyotrophic Lateral Sclerosis (ALS) is a condition that causes progressive motor function loss, and while many people with ALS use wheelchairs as mobility devices, a traditional joystick-based wheelchair interface may become inaccessible as the condition progresses. Limbitless Journey simulates the wheelchair interface by utilizing the same temporalis muscle contractions for control of in-game movements, but in a low-stress learning environment. A usability study was conducted to evaluate the serious-game-based training platform. A major outcome of this study was qualitative data gathered through a concurrent think-aloud methodology. Three cohorts of five participants participated in the study. Audio recordings of participants using Limbitless Journey were transcribed, and a sentiment analysis was performed to evaluate user perspectives. The goal of the study was twofold: first, to perform a think-aloud usability study on the game; second, to determine whether accessible controls could be as effective as manual controls. The user comments were coded into the following categories: game environment, user interface interactions, and controller usability. The game environment category had the most positive comments, while the most negative comments were primarily related to usability challenges with the flexion-based controller. Interactions with the user interface were the main topic of feedback for improvement in future game versions. This game will be utilized in subsequent trials conducted at the facility to test its efficacy as a novel training system for the ALS population. The feedback collected will be implemented in future versions of the game to improve the training process. Full article

In this research, we examined the head of the six-banded armadillo (Euphractus sexcintus) using advanced imaging techniques, including computed tomography and magnetic resonance imaging, and correlated these findings with the anatomical cross sections. For this, we analyzed three adult specimens. By integrating imaging data with anatomical cross-sections, we present a detailed description of the structures that constitute the head of this species, highlighting its most distinctive features. Therefore, a well-developed tympanic cavity was observed. The masticatory muscles, including the temporalis, masseter, medial, and lateral pterygoid muscles, were adequately delineated. Moreover, the encephalon exhibited characteristics like those of other mammals, with notable development of the olfactory bulbs. This anatomical information may serve as a valuable diagnostic reference for the clinical evaluation of different disorders in the six-banded armadillo, such as cranial malformations, fractures, neurological conditions, and neoplasms. Full article

Botulinum toxin type A (BoNT-A), a potent neurotoxin, is increasingly used to treat myogenic temporomandibular disorders (TMDs); however, the interplay between muscle atrophy and pain relief remains incompletely understood. This pilot study investigated how masseter and temporalis muscle thickness and pain intensity change over 12 weeks following BoNT-A injections in 15 patients (mean age 51.42 years) with myogenic TMD. Muscle thickness was measured via ultrasonography across multiple anatomical positions under both clenching and resting conditions at baseline and at 2, 4, 8, and 12 weeks post-injection. Significant thinning of both muscles occurred within 2 weeks, lasting until 12 weeks, but became less pronounced after the first month. Pain intensity showed parallel decreases, most notably early on, but these reductions were not consistently statistically significant. Correlation analyses revealed no strong persistent association between muscle thickness and pain except for a moderately positive correlation in the anterior temporalis at two weeks (r = 0.61, p = 0.04). BoNT-A induces rapid masticatory muscle atrophy and modest pain relief; however, these outcomes do not coincide. Pain relief was observed earlier than the full development of muscle atrophy and should be considered during TMD pain management. Full article

(1) Background: The present study was designed to analyze the relationship between masticatory muscle activity, oxygen body saturation, and heart rate in patients with temporomandibular disorders (TMDs). (2) Methods: A total of 104 individuals with a painful form of TMDs were included in the study, consisting of 72 women and 32 men, with an average age of 24 ± 3 years. The control group included 77 individuals, comprising 44 women and 33 men, with an average age of 24 ± 3 years. An electromyographic study was conducted at rest, focusing on the temporalis (TA) and masseter muscles, alongside an oxygen saturation and heart rate analysis using a pulse oximeter. (3) Results: Analysis of the correlations between oxygen saturation and the studied muscles revealed a positive correlation between the resting activity of the TA and oxygen saturation, with a small effect size in the TMDs group. This positive correlation suggests increased muscle oxygenation is associated with higher resting activity in TMDs patients. (4) Conclusions: This study indicates that oxygen body saturation is associated with increased resting activity in the temporalis muscles of individuals with TMDs. Increased muscle tension in TMDs patients may impact the metabolism of the temporalis muscle, leading to higher energy and oxygen demands. This could be linked to hypermetabolism and an increased energy burden in these muscles at rest. Full article

Background: Cocaine is a recreational drug known for its negative impact on health and social and economic life. One of the complications for cocaine abusers is cocaine-induced midline destructive lesion (CIMDL) syndrome, which includes the extensive destruction of the osteocartilaginous structures of the nose, the sinus, and the palate. Methods: Here, we describe three cases of the surgical management of CIMDL using a temporalis muscle flap combined with a Le Fort I osteotomy, which allows sufficient space for the muscle to settle. Results: The addition of the osteotomy allowed better handling of the pedicled flap, with no signs of relapse in the reported cases and high patient satisfaction. Conclusions: CIMDL syndrome is an impairing disease that negatively affects the functionality of the nasal and oral cavities, as well as the aesthetic. Surgical repair using a pedicled flap is a valid option in rehabilitated and sober patients with endothelial damage. Full article