Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Temporal Muscle”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,135 records · Page 63Linked to original sources
PubMed2005

X-ray microanalysis of elements in the masticatory muscle after paresis of the right masseter.

Muscle activity and function appear to be related to ionic concentrations in the muscle. We investigated whether muscle paresis induced by injection of Botulinum toxin A (Botox) in 16-week-old pigs over a 56-day period is associated with ionic changes in the affected muscles. Tissue samples were taken from the masseter, temporalis, medial pterygoid, and geniohyoid muscles by a standardized method and used for energy-dispersive x-ray microanalysis in an environmental scanning electron microscope. The largest increase in Na(+) was measured in the right and left sides of the masseter muscle in treated animals. Additionally, a significant elevation of Na(+) was measured in the anterior part of the temporalis muscle and in the pterygoid muscle (P < 0.05). In temporalis and pterygoid muscles, an increase in sulfur in both sides of treated pigs' heads was observed. Botox((R)) has an indirect impact on ion concentrations, resulting in changes in muscle functional capacity and adaptive compensation of paretic muscle function by other muscles.

Animals↗
PubMed2005

Reproducibility of surface EMG in the human masseter and anterior temporalis muscle areas.

The aim of this study was to test the hypothesis that surface electromyography (sEMG) recordings, made at mandibular rest position from the masseter and temporalis anterior areas, are intra- and inter-session reproducible. A template was designed and built to permit the correct electrode placement from one session to the next session. A sample of 18 subjects was examined. Two groups, homogeneous for age, sex, and craniofacial morphology were selected. The first group included asymptomatic subjects with no signs or symptoms of temporomandibular joint dysfunction (TMD) and the second group included patients suffering from muscle-related TMD. Data were obtained from different sEMG recordings made at mandibular rest position in the same session and in different sessions, repositioning the electrodes using a template designed for that purpose. The electromyograph used in this, study is part of the EMG K6-I Win Diagnostic System. Results showed that reproducibility of sEMG signals from the masseter and anterior temporalis areas at mandibular rest position is possible.

Adolescent↗
PubMed1998

Electromyographic investigation of masticatory muscles in unilateral cleft lip and palate patients with anterior crossbite.

OBJECTIVE: To evaluate the characteristics of masticatory muscle activity in operated unilateral cleft lip and palate (UCLP) patients with anterior crossbite compared with normal individuals. SUBJECTS: Sixteen male and 13 female Chinese patients with UCLP and anterior crossbite. Fifteen male and 13 female Chinese individuals without cleft abnormalities served as a control group. DESIGN: Electromyographic activity of the masseter muscles and anterior temporalis muscles was recorded bilaterally in different mandibular positions using bipolar surface electrodes. RESULTS: Compared to noncleft controls, patients with UCLP demonstrated (1) higher activation levels of masseter and temporalis muscles in the rest position, (2) lower potential function of masseter and temporalis, (3) inharmonious activity of the masticatory muscles during mandibular border movement, (4) a higher asymmetry index of the masseter and temporalis muscles, and (5) longer silent periods of the two muscles. CONCLUSIONS: The function of masticatory muscles is different in patients with UCLP with anterior crossbite. Muscle function should be considered when evaluating cleft patients for orthodontic treatment and orthognathic surgery.

Action Potentials↗
PubMed1998

Temporal change in skeletal muscle IGF-I mRNA abundance and nitrogen metabolism responses to abomasal casein infusion in steers.

Skeletal muscle IGF-I and alpha-actin mRNA responses to increased amino acid availability were investigated in young, rapidly growing steers. Four Holstein steers (208 kg BW) were surgically implanted with an abomasal cannula and jugular catheters and allowed 2 wk to recover. Steers were offered hourly a 43:57 forage:concentrate diet at 95% of ad libitum intake supplemented with continuous abomasal infusion of glucose (to replace 12.5% of metabolizable ad libitum energy intake) for 13 d before the start of abomasal infusion of 67 g of casein N/d. Biopsies of the liver and both semimembranosus muscles were removed and frozen in liquid N, and casein infusion was begun. Muscle biopsies were collected at 8, 16, 24, and 48 h, and on d 7 and 14. Nitrogen balance increased from 23.6 to 71.5 g/d (P < .001) within 24 h and remained elevated (mean = 58.4 g/d) during the 14 d of casein infusion. Plasma urea N increased from 4 to 9.5 mg/dL at 24 h and remained unchanged to d 14. Muscle IGF-I mRNA abundance increased to 215% of basal values at 16 h (P < .01), 244% of basal values at 24 h, and 222% of basal values at 48 h after initiation of casein infusion. Values reached a maximum of 274% of basal values on d 7 and then declined to near preinfusion levels on d 14. The IGF-I mRNA abundance was approximately 100 times higher in liver than in skeletal muscle and was not different on d 0 and 14. Although plasma IGF-I concentrations were numerically higher during the first 24 h of abomasal casein infusion, they were not significantly higher during the chronic phase of treatment. Plasma IGF binding protein (BP)-2 concentrations were higher at 16, 24, and 48 h after casein infusion was begun, but IGFBP-3 concentrations were not altered at these sampling times. Neither acute (first 24 h) nor chronic (daily) plasma insulin concentrations were altered by abomasal casein infusion. Plasma somatotropin concentrations were lower (P = .008) at 24 h of casein infusion and beyond. Results suggest that enhanced amino acid availability may modulate skeletal muscle protein synthesis and accretion through an autocrine or paracrine IGF-I influence.

Abomasum↗
PubMed1998

Effect of teeth clenching on isometric and isokinetic strength of ankle plantar flexion.

To investigate the effect of voluntary teeth clenching on the isometric and isokinetic exercises of the lower limbs, the association of muscle strength (peak torque, PT) and muscle activities (integrated electromyographic activity per unit of time, iEMG/s) of the three muscles of the triceps surae with teeth clenching during isometric and isokinetic plantar flexion were simultaneously measured for 12 healthy male volunteers using a Cybex 6000 Extremity Testing and Rehabilitation System and a surface EMG analyzing system. The statistical analysis demonstrated that for the isometric exercise, PT and each iEMG/s significantly increased in association with teeth clenching, and a positive correlation existed between the biting force and each variable. In contrast, no association was found with teeth clenching for the isokinetic exercise. In this study, therefore, it was found that the effect of teeth clenching differed between the isometric and isokinetic exercises.

Adult↗
PubMed2006

Electromyographic amplitude variability of chewing cycles in deaf individuals.

This study had the goal of determining if the amplitude of the surface electromyograph signals changes in terms of time of analysis and subjects, deaf or normal listeners, when estimated in a 250 ms of length window, visually determined, considering the most stable signal period from the center of the chewing cycle. In order to do this, groups with control subjects, listeners and deaf individuals, who made use of the Brazilian sign language (LIBRAS), were studied. All participants performed continuous 5 s of chewing for the electromyographic recording of the temporalis and masseter muscles. The normalized RMS values of three chewing cycles were compared between and among groups. The results from the Kruskall-Wallis test did not show any statistically significant differences (p > 0.05) between the normalized RMS values obtained in the three individual chewing cycles, for each of the two completed and evaluated cycles, in both groups studied. The Mann-Whitney test showed that the mean normalized RMS values obtained in the first chewing cycle were higher for the control group when compared to the mean amplitude values of the first chewing cycle of the group of deaf volunteers. It can be concluded that, in these experimental conditions, the RMS values obtained from the select windows of 250 ms length duration, in relatively stable periods of the electromyographic signal of chewing cycles did not suffer any changes in terms of EMG register duration, in both studied groups, but does give evidence of the differences among the groups.

Adolescent↗
PubMed1982

[Frequency analysis (FFT) of electromyography and development of the quiet period in the masticatory muscle discharge].

The purpose of this study was to analyze the control mechanism of quiet period (silent period, QP) in myoelectric signals of the masseter and the anterior part of temporalis by the measure of frequency analysis (FFT) and the power spectra, according to the bite force developement. Surface myoelectric signals of te masseter and the temporalis (both sides) of nine human subjects with normal occlusion were recorded during biting movements. Subjects were asked to increase their forces rapidly to their maximum bite force levels at the decided three rate (0.5sec, 1.0sec and 2.0sec) respectively. QPs (duration; 10 approximately 70ms) were observed (occurrence rate; 44%) almost simultaneously in four muscles at both experimental conditions of the high accelerative movements (0.5sec) and of low levels of bite force remarkably. Frequency analyses were carried out by means of Fast Fourier Transform about myoelectric signals for the period of each 50ms before and after QP occurrence. In the higher frequency bands (200 approximately 480Hz), power spectra "AFTER QP" were distributed with high energy density, whereas "BEFORE QP" were characterized in low frequency bands (20 approximately 180Hz) with low energy. By these analysis, following results were discussed such as that the recruitment of phasic motor units (high frequency bands of power spectra) appeared with fast rate coding in the EMG of QP occurrence, and it should be natural for the neural switching mechanism to be activated in QP occurrence in order to transfer from tonic units to phasic ones of EMG.

Adult↗
PubMed1995

Posterior bite raising effects on a primary anterior crossbite case.

Stainless steel crowns were cemented on the mandibular primary molars to make bite raising for an anterior reversed bite case. Chewing force and MKG were recorded before and after bite raising. Data from MKG revealed that co-ordination pattern of muscle activities after bite raising became higher in masseter muscles than those before anterior reversed bite was corrected easily without any incisal interferences by using this treatment method.

Bite Force↗
PubMed1994

Effect of tooth clenching and jaw opening on pain-pressure thresholds in the human jaw muscles.

The measurement of the pain-pressure threshold in the human jaw muscles may be affected by variables such as the size of the pressure-transducer recording surface and the rate of applied pressure. The jaw muscles have a complex architecture that results in changes in muscle stiffness and compliance when different motor tasks are performed. Such changes in the jaw muscles are likely to affect the pain-pressure threshold. The central motor program associated with different tasks may also affect the pain-pressure threshold. A pressure algometer was used to measure the pain-pressure threshold in various regions of the masseter and temporalis muscles at different magnitudes of tooth clenching and jaw gape. The pain-pressure threshold increased at all recording sites as muscle contraction associated with tooth clenching increased. The pain-pressure threshold was not affected when the jaw gape changed. There were no apparent regional differences in pain-pressure thresholds in the masseter or temporalis muscles at different amounts of tooth clenching or jaw gapes. Pain-pressure thresholds were consistently higher in the temporalis muscle. When quantitative measures of jaw muscle pain-pressure thresholds are planned, the nature of the motor task should be controlled.

Adult↗
PubMed1993

Vertical forces developed by the jaw elevator muscles during unilateral maximal clenching and their distribution on teeth and condyles.

The activity of the jaw elevator muscles (EMG) was recorded during maximal clenching in ICP and unilaterally on 2nd and 1st molars, premolars, canines and central incisors in ten subjects with complete dentitions, normal occlusal relationships, and without signs and symptoms of craniomandibular disorders. The EMG activities were converted to relative muscle force. The distribution of this relative muscle force on teeth and condyles was then calculated by means of a three-dimensional mathematical model. The results suggest that the magnitude of the muscle force is strongly associated with the localization of the biting point. Thus the greatest muscle force is produced during clenching in the intercuspal position (100%). At unilateral clenching 75% of this ICP-force is reached during rubber pad clenching on 2nd molars, 85% during rubber pad clenching on 1st molars and 45% during clenching on incisors. The calculations of the mathematical model showed then that highest bite force should be produced on 2nd molars (55% of the muscle force produced in ICP-clenching) and lowest on incisors (20%). Highest condylar load should be found on non-biting side condyles (20% of the muscle force produced in ICP-clenching) and lowest on biting side condyles (0%).

Adult↗
PubMed1980

Centric relation: a comparison of muscle-determined position and operator guidance.

Fifteen subjects were used to determine direction and magnitudes of shifts in condylar position when interocclusal records were made by biting hard or easy on a leaf gauge or wax. Electromyographic recordings were made of the temporal and masseter muscles during interocclusal registrations to determine which muscles were most active in seating the condyle when the leaf gauge was used. Results indicated no significant difference in condylar position superoinferiorly between registrations. Biting hard on a leaf gauge caused a significantly more posterior position of the condyle. When this technique is used for obtaining interocclusal registrations, the temporal muscles are more active than the masseters.

Adult↗
PubMed1995

Electromyographic analysis of the masticatory muscles of patients after complete rehabilitation of occlusion with protection by non-working side contacts.

Surface electromyography was used to study the function of the anterior temporal, surface masseter, deep masseter and anterior digastric muscles of 14 patients after complete rehabilitation of occlusion with fixed prostheses and/or removable partial prostheses. All patients had a balanced occlusion with protection by non-working side contacts during lateral excursion. Mean resting myoelectric activity was 2.5-3.8 microV, showing no hypertonia or muscular spasm. When patients clenched their teeth (i.e. exerted maximum voluntary occlusal force in centric occlusion), the anterior temporal muscles were the most active, followed by the surface masseters; the digastrics were significantly less active. During lateral displacements, the muscles exhibiting significantly higher potentials than the other muscles monitored were the working side anterior temporal muscle and the contralateral surface masseter. During mastication, the muscle that was most active in relation to its contralateral homologue was the working side surface masseter, the difference between the two being statistically significant.

Adult↗
PubMed2005

Temporally controlled targeted somatic mutagenesis in skeletal muscles of the mouse.

To generate temporally controlled targeted somatic mutations selectively and efficiently in skeletal muscles, we established a transgenic HSA-Cre-ER(T2) mouse line in which the expression of the tamoxifen-dependent Cre-ER(T2) recombinase is under the control of a large genomic DNA segment of the human skeletal muscle alpha-actin gene, contained in a P1-derived artificial chromosome. In this transgenic line Cre-ER(T2) is selectively expressed in skeletal muscles, and Cre-ER(T2)-mediated alteration of LoxP flanked (floxed) target genes is skeletal muscle-specific and strictly tamoxifen-dependent. HSA-Cre-ER(T2) mice should be of great value to analyze gene function in skeletal muscles, and to establish animal models of human skeletal muscle disorders.

Actins↗