Left Temporalis Research Articles

Biofotogrametric and electromyographic analysis in different position in women with temporomandibular disorder.

Introduction: The relationship established between TMJ (Temporomandibular Joint), cranium and cervical spine requires the synchrony of these structures for the proper performance of stomatognathic functions and muscle balance in this region. Objective: Evaluate the craniocervical posture and the electrical activity of masticatory and cervical muscles in sitting and standing positions in patients with TMD, correlating these variables. Method: The participants were 21 women, with mean age 28 ± 5.33 years and severe TMD. The participants were evaluated by electromyography of the masseter, anterior temporal and sternocleidomastoid (SCM) and upper trapezius muscles, bilaterally, in standing and sitting position. The body posture was evaluated by biophotogrammetry, with analysis of the Head Horizontal Alignment (HHA) and Acromion Horizontal Alignment (AHA) in frontal view and the Head Vertical Alignment (HVA) and Head Horizontal Alignment related to seventh cervical vertebra (HHAc7) in lateral view. Results: The electrical activity of masticatory muscles during resting did not differ between the different evaluated positions. During maximum intercuspation, the electrical activity was significantly lower in the left masseter (p=0.016), higher in the left anterior temporal muscle (p=0.046) and higher in the right (p=0.005) and left (p=0.015) upper trapezius muscles, in standing position when compared to sitting position. The photogrammetric values found were within the normal range. There was a significant and moderate negative correlation between the left SCM muscle and the right (r=0.386) and left (r=0.428) HHAc7 angle. Conclusions: Muscular electrical activity was modified with the change between sitting and standing positions, with an increase in cervical muscle recruitment and asynchrony of the masticatory muscles. Thus, it can be inferred that there is a postural destabilization with possible head anteriorization during maximum intercuspation, reinforcing the relation of synergy between the masticatory and cervical muscles.

Severity of Sleep Bruxism and its Implications for the Stomatognathic System in Healthy Subjects

BACKGROUND: Sleep bruxism (SB) changes the functionality patterns of the stomatognathic system. However, its severity can be an aggravating factor in the function of this complex system.
 AIM: The purpose of the study was to investigate the stomatognathic system of healthy subjects with different severity of SB, as determined by BiteStrip.
 METHODS: Thirty-four subjects were divided into two groups: Mild SB (n = 15) and severe SB (n = 19). Electromyograph was used to evaluate the electromyographic activity of the right masseter (RM), left masseter (LM), right temporal (RT), and left temporal (LT) muscles at mandibular rest, right and left laterality, protrusion, and maximum voluntary contraction. Molar bite force was measured by the dynamometer. The data were tabulated and submitted for statistical analysis (p < 0.05).
 RESULTS: Molar bite force was significantly lower in the severe SB group. There was a significant increase in electromyographic activity in the severe SB group for the mandibular rest tasks (RM, RT, and LT), protrusion (RM, LM, RT, and LT), and right and left laterality in the temporalis muscles. There was a significant decrease in electromyographic activity in the severe SB group in maximum voluntary contraction for the masseter and temporalis muscles.
 CONCLUSION: Subjects with severe SB demonstrated greater functional impairment of the stomatognathic system, mainly affecting the electromyographic activity and molar bite force.

Temporalis Muscle Abscess With Secondary Extension Into the Orbit.

A 33-year-old woman presented with intermittent left-sided periorbital swelling and facial pain. She had a history of dental procedures to the left upper and lower molars a few months prior. MRI revealed an abscess within the left temporalis muscle measuring 1.5 × 1.9 × 3.9 cm with associated mild inflammation involving the left lateral orbit (Fig. 1). An ultrasound-guided aspiration of the abscess revealed Streptococcus, Prevotella, and Propionibacterium species. After treatment with intravenous piperacillin/tazobactam for 4 days, her eye exam continued to worsen with a new abduction deficit on the left side and 1 mm of proptosis. Repeat MRI demonstrated a distinct, 1.3 cm subperiosteal abscess along the lateral orbit (Fig. 2). The patient was taken to the operating room for orbitotomy and drainage of abscess with placement of a Penrose drain. A culture of the contents showed no growth as she had received several days of intravenous antibiotics. The patient subsequently had an uncomplicated postoperative course and was discharged 1 week later.FIG. 1.: Initial axial MRI showing a large abscess (arrow) within the left temporalis muscle and associated inflammatory changes within the preseptal and postseptal tissues.FIG. 2.: Repeat axial MRI demonstrating a subperiosteal abscess of the left lateral orbit (arrow) adjacent to the temporalis abscess causing unilateral proptosis.This is a case of a temporalis muscle abscess with likely secondary extension into the orbit. To the authors’ knowledge, this presentation has never been described previously. The authors suspect that the route of infectious extension into the orbit was via the zygomaticotemporal foramen which is located at the anterolateral wall and transmits the zygomaticotemporal neurovascular bundle.

Is there a difference in the electromyographic activity of the masticatory muscles between individuals with temporomandibular disorder and healthy controls? A systematic review with meta‐analysis

The diagnosis of temporomandibular disorders (TMD) is complex, and it is not yet clear in the literature whether the clinical changes associated with these disorders are also reflected in the electromyographic (EMG) activity of the muscles of mastication. To determine whether there is a difference in the electromyographic activity of the masticatory muscles between individuals with TMD and healthy controls. ScienceDirect, EMBASE, MEDLINE, PEDro, SciELO, CINAHL and LILACS databases from January 2000 to February 2019. Cross-sectional studies, crossover studies and randomised controlled trials evaluating EMG activity of right and left masseter and anterior temporal muscles in patients with TMD and healthy controls. Two independent assessors extracted data from the selected articles. The risk of bias was determined using a checklist for assessing methodological quality created based on the guidelines of the Strengthening the Reporting of Observational Studies in Epidemiology and International Society of Electrophysiology and Kinesiology. Mean differences and 95% confidence intervals were calculated and combined in meta-analyses. A total of 51267 studies were retrieved, and 12 were included in this review. Only two studies enabled the comparative analysis of the results. The different EMG signal capturing, processing and analysis methods used constitute an important limitation to the comparative analyses of the results reported in the studies selected for the present review. This systematic review did not demonstrate evidence of significant differences in the EMG activity of the masticatory muscles between individuals with TMD and healthy controls.

Comparative evaluation of the masticatory efficiency of complete dentures with bio-engineered teeth and conventional denture teeth using electromyography – A randomised crossover clinical study

Background and Objective: Resorption of residual ridge is common problem related to edentulous mandible. One of the main causes of resorption of denture-supporting structures is traumatic or excessive force transmitted through the prosthesis. The resilient-layer and occlusal-reactive dentures are clinical attempts developed for impact reduction and distribution of the masticatory load to the edentulous ridge. Bio-engineered posterior denture teeth which was used in this study have resilient silicone material lining which lead to cushioning effect and reduced the force transmitted to the basal bone. This study was done to assess and compare the masticatory efficiency of complete dentures with bio-engineered teeth and conventional denture teeth using electromyography (EMG) analysis. Methodology: The present study was conducted on 09 completely edentulous patients who reported to the department of prosthodontics and crown and bridge. Two Groups Were Made: Group A - conventional denture and Group B - denture with bio-engineered teeth. All the patients were randomly allotted to Group A or B using random allocation software, after 3 months EMG recording was done, and then, all the patients were provided another set of denture, other than the group in which they had allocated previously. EMG recording was done again after 3 months of providing the denture of other group. Results: Paired t-test showed no statistically significant difference in EMG reading of left masseter (P = 0.514), right masseter (P = 0.545), left temporalis (P = 0.954), and right temporalis (0.944) between both the groups. Conclusion: Both the dentures did not show any statistically significant difference in terms of EMG activity, which indicates that the masticatory efficiency of bio-engineered teeth denture is comparable to that of conventional denture.

Effect of Mastication Muscle Activity on Prefrontal Cortex NIRS Measurement: A Pilot Study.

Changes in NIRS signals are related to changes in local cerebral blood flow or oxy-Hb concentration. On the other hand, recent studies have revealed the effect of chewing gum on cognitive performance, stress control etc. which accompanied brain activity in the prefrontal cortex (PFC). However, these relationships are still controversial. To evaluate the chewing effect on PFC, NIRS seems to be a suitable method of imaging such results. When measuring NIRS on PFC, blood volume in superficial tissues (scalp, skin, muscle) might have some affect. The aim of the present study was to clarify the effect of the anterior temporal muscle on NIRS signals during gum chewing. Eight healthy volunteers participated. Two-channel NIRS (HOT-1000, NeU, Japan), which can distinguish total-Hb concentrations in deep tissue and superficial tissue layers, was used. In addition to a conventional optode separation distance of 3.0cm, Hot 1000 has a short distance of 1.0 cm (NEAR channel) to measure NIRS signals that originate exclusively from surface tissues. NIRS probes were placed at Fp1 and Fp2 in the normal probe setting. The headset was displaced to the left in order to allow the left probe to be placed over the left anterior temporal muscle. In the normal setting, the superficial signal curve shows no notable change; however, the neural (calculated and defined in HOT-1000) and deep curves show an increase during the gum chewing task. At the deviated setting, all three signals show marked changes during the task. Total-Hb concentration in the deviated probe setting is significantly large (p<0.05) than that of in the normal probe setting. When using gum chewing as a task, it would be better to consider a probe position carefully so that the influence of muscle activity on NIRS signal can be distinguished.

Impact of chronic allergic rhinitis on bite force and electromyographic activity of masseter and temporalis muscles of adult women.

BackgroundThe aim of this study was to analyse the stomatognathic system of adult women with chronic allergic rhinitis by means of molar bite force and electromyographic activity of the masseter and temporalis muscles. Material and MethodsA total of 26 subjects were screened and divided into two distinct groups: chronic allergic rhinitis group (n = 13) and healthy control group (n = 13). Subjects were assessed by maximal molar bite force (right and left) and normalized electromyographic activity of mandibular tasks (rest, right and left laterality, protrusion and maximal voluntary contraction). Data were submitted to Student’s t test (p< .05). ResultsThere was significant difference in right (p = .03) and left (p = .04) maximal molar bite force with force reduction in the chronic allergic rhinitis group. There was significant difference in normalized electromyographic activity in maximal voluntary contraction in the right (p =.01) and left (p = .01) temporalis muscles, with increased electromyographic activity in the masticatory muscles for the chronic allergic rhinitis group. ConclusionsThe results suggest that chronic allergic rhinitis in adult women promoted negative changes in the electromyographic activity of temporalis muscles in maximal voluntary contraction and maximal molar bite force. Key words:Rhinitis, occlusal force, electromyography, masticatory muscles.

Autologous Hematopoietic Stem Cell Therapy of the Subjects with Systemic Sclerosis: Electromyographic Results of the Masticatory Muscles.

Musculoskeletal system impairment is a major cause of functional alterations in subjects with systemic sclerosis. Autologous hematopoietic stem cell therapy (AHSCT) may have an important role in the treatment functional of systemic sclerosis patients. The aim of this pilot study was to assess whether AHSCT interferes with the electromyographic activity of the masseter and temporalis muscles of subjects with systemic sclerosis. Before transplantation, seven subjects with systemic sclerosis (mean age [± SD], 40.1 ± 9.6 years) underwent electromyographic analysis of the masseter and temporalis muscles in mandibular tasks at rest, right and left laterality, protrusion and maximum voluntary contraction. Two months after AHSCT, the subjects re-evaluated using the same methods. Data were analyzed using the repeated-measure test, with p&lt;0.05 considered to be statistically significant. Two months after AHSCT, there was reduction in normalized electromyographic activity in the dental clenching in maximal voluntary contraction, with significant differences, for the left temporal muscle (p=0.04). AHSCT in subjects with systemic sclerosis promotes alterations in stomatognathic system function, especially those related to electromyographic activity of masticatory muscles.

Unedited pathological recurrent association of palmomental and rooting archaic reflexes in a young woman with severe traumatic brain lesions – case presentation and physiopathological considerations

Introduction. Archaic reflexes are present in infancy, disappear as the brain matures, but reappear in pathological conditions. Case report. A 29-years-old woman has suffered a severe traumatic brain injury. She was admitted to neurorehabilitation 6 months after neurosurgical interventions (ventriculoperitoneal shunt for traumatic hydrocephalus, emerged after decompressive craniectomy). Neurological examination revealed a minimal conscious state, spastic tetraparesis, trismus, central facial palsy, nystagmus, bilateral palm-chin reflex, and a “mitigated” variant of the rooting reflex. The left corneal, snout and glabellar reflexes were absent. Osteotendinous reflexes were brisk, Babinski sign was bilaterally present, palmar and plantar grasp reflexes were absent. The trismus has persisted and chewing remained severely disabled after botulinum toxin injected in the left temporalis muscle and bilaterally in the masseter. The patient was fed by percutaneous endoscopic gastrostomy tube. Neurologic evolution remained stationary after two months of rehabilitative nursing. Discussion. The palmomental reflex described by Marinescu and Radovici, is elicited by scratching the thenar eminence of the palm, and consists of an ipsilateral twitch of the mentalis muscle. Baby rooting for milk is a primitive trigemino-facial reflex found in newborn infants. The lower lip is lowered, and the tongue is moved in the direction where the cheek near the corner of the mouth is brushed. The lockjaw has “mitigated” the classical pattern of clinical response. Repeated stimulation causes a unilateral mentalis muscle response, similar to the palm-chin reflex. The severe traumatic brain lesions have induced pathological reappearance of the palmomental and rooting archaic reflexes, in a unique, unedited pathological association. Key words: palmomental reflex (Marinescu Radovici reflex); rooting reflex; archaic reflexes; botulinum toxin; traumatic brain injury; minimal conscious state,

Effects of Parkinson's disease on molar bite force, electromyographic activity and muscle thickness of the masseter, temporal and sternocleidomastoid muscles: A case-control study.

Parkinson's disease is a neurological disorder that promotes motor changes in the body. The aim of this study was to investigate the impairment of the stomatognathic function regarding molar bite force, electromyographic activity and thickness of the craniocervical muscles in patients with Parkinson's disease in comparison with those in asymptomatic controls. Twenty-four subjects were divided into two groups, a Parkinson's disease group (n=12) and a control group (n=12). The subjects were evaluated on the basis of molar bite force, electromyographic activity (rest, right and left laterality, protrusion, maximum voluntary contraction) and thickness (rest and maximum voluntary contraction) of the right and left temporal (anterior portion), masseter and sternocleidomastoid muscles. The results were submitted to a multivariate analysis of variance (MANOVA) to compare the means of the two independent groups, considering diagnosis of Parkinson's disease and craniocervical muscles as independent variables. For the post hoc comparisons, Bonferroni correction was used (P<0.05). Parkinson's disease group presented lower mean values both sides for maximal molar bite force, significant increases in the electromyographic activities during mandibular tasks, lower mean thickness values of the masseter and sternocleidomastoid muscles, and higher mean thickness values of the temporalis muscles (anterior portion). The results suggest that patients with Parkinson's disease may present functional changes of the stomatognathic system, related to bite force, electromyographic activity and thickness of the craniocervical muscles. The greater temporal muscle thickness in Parkinson's disease patients may compromise their daily life activities, especially with respect to chewing and nutrition.

Myosite ossifiante du muscle temporal après polytraumatisme

La myosite ossifiante traumatique (MOT) du muscle temporal est une pathologie extrêmement rare. Une limitation de l’ouverture buccale est le symptôme clé. Les examens d’imagerie sont très utiles au diagnostic, le CT-scanner de la face étant l’examen le plus performant pour la détection de la MOT. Le meilleur traitement est la résection chirurgicale complète. Les cas de myosite ossifiante traumatique dans la région de la tête et du cou sont rares. Les atteintes au niveau du muscle temporal sont encore plus rares. Nous présentons ici le cas d’une ossification isolée du muscle temporal gauche après un polytraumatisme. L’intérêt de l’observation clinique du cas présenté est donc de documenter la littérature. Le diagnostic différentiel et les signes pathognomoniques présents sur les examens d’imagerie seront également détaillés.

Facial onset sensory and motor neuronopathy: a motor neuron disease with an oligogenic origin?

Objective: To describe a patient with facial onset sensory and motor neuronopathy (FOSMN) carrying heterozygous mutations in both TARDBP and SQSTM1 genes. Methods: The patient underwent neurological, neuropsychological, and neurophysiological examinations. Brain magnetic resonance imaging (MRI) and extensive genetic analysis were also performed. Results: The neurological examination showed dysphonia, left trigeminal hypesthesia, and left masseter and temporalis muscle atrophy. Mild cognitive impairment, affecting predominantly executive functions and social cognition, was appreciable in the neuropsychological examination. The electrophysiological studies revealed: left abnormal blink reflex; neurogenic changes in bulbar and cervical muscles; normal motor evoked potential amplitude, central motor conduction time and cortical silent period. Brain MRI showed right-predominant frontotemporal atrophy. Genetic analysis showed a heterozygous mutation in TARDBP (p.A390S) and in SQSTM1 (p.P392L), both previously described as causing amyotrophic lateral sclerosis. The SQSTM1, but not the TARDBP, mutation was found in both healthy siblings. Conclusions: Our data provide new clinical, neuroimaging, and genetic evidence that FOSMN is a neurodegenerative disease of the motor neuron disease and frontotemporal dementia spectrum, with a possible oligogenic origin. Multicentric efforts focusing on cognitive and genetic studies are necessary to confirm this hypothesis and to determine if ALS genes should be systematically screened in these patients.

Impact of Parkinson's disease on the efficiency of masticatory cycles: Electromyographic analysis.

BackgroundThis study evaluated the efficiency of masticatory cycles by means of the linear envelope of the electromyographic signal of the masseter and temporalis muscles in individuals with Parkinson’s disease.Material and MethodsTwenty-four individuals were assigned into two groups: with Parkinson’s disease, average ± SD 66.1 ± 3.3 years (n = 12) and without the disease, average ± SD: 65.8 ± 3.0 years (n = 12). The MyoSystem-I P84 electromyograph was used to analyze the activity of masticatory cycles through the linear envelope integral in habitual mastication of peanuts and raisins and non-habitual mastication of Parafilm M®.ResultsThere was statistically significant difference (P ≤ 0.05) between individuals with Parkinson’s disease and without the disease in non-habitual mastication of Parafilm M®, in the right temporal muscle (P = 0.01); habitual mastication of peanuts, in the right temporal muscle (P = 0.02), left temporal muscle (P = 0.03), and right masseter muscle (P = 0.01); and habitual mastication of raisins in the right temporal muscle (P = 0.001), left temporal muscle (P= 0.001), right masseter muscle (P= 0.001) and left masseter muscle (P= 0.03).ConclusionsThese results suggest that Parkinson’s disease interferes in the electromyographic activity of the masticatory cycles by reducing muscular efficiency. Key words:Parkinson’s Disease, electromyography, masticatory efficiency, masseter muscle, temporal muscle.

Influence of sleep bruxism severity on masticatory efficiency: electromyographic analysis.

The objective of the present study was to ascertain masticatory efficiency by evaluating electromyographic activity in the masseter and temporalis muscles in subjects with sleep bruxism of varying severity, as determined by BiteStrip. Thirty-four subjects with sleep bruxism were divided into two groups: a mild sleep bruxism group with a mean (± standard deviation) age of 31.3 ± 6.2 years (n = 15) and a severe sleep bruxism group with a mean age of 29.8 ± 7.1 years (n = 19). Full-night polysomnography (PSG) was performed in eligible subjects. The linear envelope integral was used to determine masticatory efficiency on the basis of the electromyographic signal of the masseter and temporalis muscles during habitual and non-habitual chewing. There was significantly higher (p .05) electromyographic activity in the severe bruxism group than in the mild bruxism group during both peanut chewing in the right (p = .03) and left (p = .03) temporalis muscles and raisin chewing in the right (p = .01) and left (p = .05) temporalis muscles. Furthermore, Parafilm M chewing showed similar results in the right (p = .008) and left (p = .02) temporalis muscles. These results suggested that subjects with severe sleep bruxism had lower masticatory efficiency.

Spinocerebellar ataxia: Functional analysis of the stomatognathic system.

BackgroundNeurodegenerative diseases that affect the cerebellum, especially in elderly individuals, cause impairment of motor coordination and quality of life. The presente study evaluated the electromyographic activity and thickness of the right and left masseter and temporal muscles, and the maximum molar bite force of individuals with spinocerebellar ataxia.Material and MethodsTwenty-eight individuals were divided into two groups: those with (n=14) and without (n=14) spinocerebellar ataxia. Data on the masticatory muscles obtained from the electromyographic activity (resting, right and left laterality and protrusion), muscle thickness (maximal voluntary contraction and tensile strength) and maximum bite force (right and left) were tabulated and descriptive analysis using Student’s t-test (P ≤ 0.05).ResultsIn the comparison between groups, greater electromyographic activity was demonstrated for individuals with spinocerebellar ataxia, with a statistically significant difference in protrusion and laterality for the temporal muscles (P = 0.05). There was no statistically significant difference between the groups for masticatory muscles thickness in the conditions evaluated. For maximum molar bite force, the group with spinocerebellar ataxia showed lower bite force (P ≤ 0.05).ConclusionsThe data obtained suggest that spinocerebellar ataxia promotes functional reduction in the stomatognathic system, mainly affecting the electromyographic activity and bite force, hindering chewing, with a resultant alteration of nutritional intake and a decrease of quality of life. Key words:Spinocerebellar ataxia, electromyography, muscle thickness, bite force, masseter muscle, temporal muscle.

A Difficult Case of Medication-Overuse Headache Complication in a Patient Suffering from Orofacial Pain following Dental Treatment

Aim: To report a difficult case of medication-overuse headache complication in a patient with orofacial pain following dental treatment.Case: A patient in her 60s had undergone repair of the left upper first premolar that had lost a filling by a dentist about 6 months prior. As root canal treatment was initiated, the patient started experiencing pain on the left side of the head and face. As she experienced no improvement of symptoms, she visited an otology clinic for a detailed examination, but no cause was identified. Subsequently, the patient was referred to our hospital. At that time, she was frequently taking prescribed loxoprofen. No acute inflammation was found in the tooth, therefore the pain was suspected to be associated with myofascial pain of the left temporal muscle. Simultaneously, the patient suffered an ankle fracture. She underwent treatment in an orthopedic surgery department, which used loxoprofen to treat the pain. Subsequently, head and face pain on the left side worsened. Because the cause was not identified, the patient was referred to the pain clinic department of a general hospital. By then the patient was suffering from tension headache and took analgesics on a daily basis. Based on this, medication-overuse headache was suspected. Loxoprofen was immediately discontinued and goreisan was prescribed as an alternative. Thereafter, the head and face pain on the left side almost disappeared.Conclusion: Medication-overuse headache may occur due to the overuse of medication in patients with primary headache. Prior to prescribing analgesics, dentists need to understand the patient’s past history of headaches. Drug administration without due consideration should be avoided. Additionally, the patient should also be informed of the risk of medication-overuse headache.

Thermographic Study of the Orofacial Structures Involved in Clarinetists Musical Performance.

Introduction: Wind instrumentalists like clarinetists, may present a muscular hyperactivity on certain groups of the cranio-cervico-mandibular complex, due to their musical activity. Therefore, the use of infrared thermography can be used to assess and characterize the orofacial structures involved in clarinet performance. Aim: The objective of this study was to analyze and record the thermal patterns using the thermographic camera Flir® E60sc to evaluate anatomically and physiologically certain orofacial structures of the cranio-cervical-mandibular complex, such as the masticatory muscles and the region of the temporomandibular joint. Methodology: A sample of 30 clarinetists completed an individual questionnaire composed of two components (musical and clinical history of the participant), and were subjected to a clinical examination. Four thermographic images were taken of the cranio-cervical-mandibular complex at a rest position with frontal, right lateral, left lateral and anterior dentoalveolar components views. Each musician performed a piece of music for an uninterrupted period of 10 min. New thermographic images were captured with the same incidences, after the performance, respecting the same protocol. Results: There were statistically significant differences in the areas corresponding to the left temporal muscle, the orbicularis muscle (labial component), the left and right perioral teguments, as well as in the upper central incisors. There was also statistical evidence regarding the initial and final temperature asymmetries regarding temporal muscle and orbicular muscles (labial and marginal components). Conclusion: Infrared thermography has been shown to be an effective complementary diagnostic tool in the monitorization of the cranio-cervical-mandibular complex of clarinetists.

Ultrasonographic evaluation of jaw elevator muscles in young adults with bruxism and with and without attrition-type tooth wear: A pilot study

ABSTRACT Objective This pilot study was planned to analyze masticatory activation in bruxism patients with and without attrition by ultrasonographic evaluation of mandibular adductor muscles. Methods Sixty bruxism patients (group 1: 30 without attrition, group 2: 30 with attrition) and an age-sex matched control of 30 (group 3) were clinically examined. The thickness of bilateral temporalis and masseter muscles during clench and rest was measured by ultrasonography. Results The mean muscle thicknesses were higher in bruxing patients than in controls. In group 2, the clench/rest ratio (C/R) of the right and left masseter and temporal muscles were higher than the control group (p = 0.03, p = 0.01, p = 0.04, p = 0.03, respectively). Conclusion The thickness of chewing muscles increases with bruxism. The occlusal forces in the teeth increase, and therefore, the tooth wear increases. Ultrasonographic muscle thickness can be used to determine muscle activity in bruxism patients.

Pericranial Tenderness in Females With Episodic Cervical Headache vs Asymptomatic Controls: A Cross-sectional Study

ObjectivesThe purpose of this study was to compare pericranial tenderness of females with episodic cervical headache vs matched asymptomatic controls. MethodsThrough a single-blind, cross-sectional study, pericranial tenderness was compared between 20 females with episodic cervical headaches (29.4 ± 13.2 years) and 20 age-matched female asymptomatic controls (30.1 ± 13.7 years). Pericranial tenderness was bilaterally measured in a headache-free period with the “total tenderness score” (TTS) in the suboccipital, temporal, frontal, masseter, upper trapezius (UT), levator scapula, and sternocleidomastoid (SCM) muscle insertions. Passive cervical mobility, headache intensity, frequency, and duration were secondary outcomes. Analysis was done with a 95% confidence level (SPSS version 22). The Mann-Whitney U-test was used to compare pericranial, cephalic, cervical, and muscle-specific tenderness between groups. Correlations between passive cervical mobility and headache characteristics and the TTS were estimated with Spearman’s ρ. ResultsThe headache group (1.25 ± 0.89) showed a 2 times higher (P < .05) pericranial TTS compared to the control group (0.62 ± 0.70). Higher (P < .05) scores were observed for the left suboccipital, temporal, masseter, UT, levator scapula, and SCM muscles and the right suboccipital, frontal, UT, and levator scapula muscles. Grouping the tenderness scores into cervical (suboccipital, UT, levator scapula, SCM) and cephalic (frontal, temporal, masseter) regions revealed greater scores (P < .05) in the headache group. In the latter, the TTS was significantly positively correlated with passive cervical extension (ρ = 0.78). ConclusionConsistent higher tenderness scores were observed and suggest involvement of sensitization in patients with episodic cervical headaches. A positive correlation was seen between passive cervical extension and sensitivity.

Alterations in the stomatognathic system due to amyotrophic lateral sclerosis.

Objectives:To compare the molar bite force, electromyographic activity, chewing efficiency and thickness of the masseter and temporalis muscles in individuals with amyotrophic lateral sclerosis (ALS) and healthy individuals.Material and Methods:Thirty individuals enrolled in the study were divided into the study group (with ALS, n=15) and control group (healthy individuals, n=15). Data regarding molar bite force (right and left), electromyographic activity (mandibular rest, right and left laterality, protrusion, and maximum voluntary contraction), chewing efficiency (habitual and non-habitual), and masticatory muscle thickness (rest and maximum voluntary contraction) were tabulated and subjected to statistical analysis (Student’s t-test, p≤0.05).Results:Comparisons between the groups demonstrated a statistically significant increase in the electromyographic activity of the right masseter (p=0.03) and left masseter (p=0.03) muscles during mandibular rest; left masseter (p=0.00), right temporalis (p=0.00), and left temporalis (p=0.03) muscles during protrusion; and right masseter (p=0.00), left masseter (p=0.00), and left temporalis (p=0.00) muscles during left laterality, in individuals with ALS as compared with healthy individuals. A statistically significant decrease was observed in the habitual chewing efficiency of the right masseter (p=0.00) and right temporalis (p=0.04) muscles in individuals with ALS. No statistically significant difference between the groups was found the masticatory muscle thickness and maximal molar bite force.Conclusions:ALS may lead to modifications in the activities of the stomatognathic system, including muscular hyperactivity and reduction in chewing efficiency; however, no change has been observed in the masticatory muscle thickness and molar bite force.