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 847 records · Page 47Linked to original sources

[Cholesteatoma surgery. Cavity repair. Personal technique].

We report the cases of 158 ears treated surgically for cholesteatoma in the past 6 years. Early diagnosis makes more conservative surgery possible (retraction pockets, reconstructive techniques). However, many interventions still produce large cavities that must be repaired. The use of autologous and heterologous materials in the reduction of these large cavities has been described. Failure of these filling techniques as a result of resorption or intolerance in some cases leads to chronic ear discharge or residual cholesteatomatous growth between the cavity and the filling tissue which requires reoperation. We describe our surgical technique, which aims to produce a wide, well-ventilated outer ear canal with adequate drainage of epithelial debris. A meatal skin flap is created, which is followed by a wide meatoplasty and the creation of a musculoaponeurotic flap using this meatal skin flap as pedicle. The musculoaponeurotic flap is sutured to the subcutaneous tissue and to the temporal muscle. This produces a wide external ear canal when the meatal skin flap is moved to repair the cavity.

Adolescent↗

The influence of eye closure on muscle activity in the anterior temporal region.

In the experiments reported here the influence of eye closure upon the muscle tone in the region of the anterior temporal muscles was studied during mandibular rest in four patients with TMJ dysfunction and in four healthy subjects. The muscle activity as well as the cortical activity (EEG) of the patients was influenced by changes in visual stimulation. EMG (the anterior temporal region) and EEG (parieto-occipital region) were recorded with needle electrodes. Ongoing EMG activity was present in all patients when their eyes were open. Closure of both eyes reduced the muscle activity by 50-100%. Closure of one eye could also abolish all activity but the degree of this influence was variable. Opening of the eyes blocked the alpha rhythm in the EEG. Simultaneously, increased activity was observed in the region of the temporal muscle. The activity level in the temporal region of the healthy subjects was very low and could easily be reduced to noise level using ordinary relaxation manoeuvres without eye closure. The results reported here indicate that visual stimulation may increase muscle tone in the temporal region probably as part of an arousal reaction. It is, however, possible that the activity might stem not from the temporalis muscle but from the temporoparietalis.

Blinking↗

Differentiation of fibres in human masseter, temporal and biceps brachii muscles. A histochemical study.

Masseter, temporal and biceps brachii muscles were histochemically evaluated for fibre type differentiation on 19 aborted fetuses (gestational ages 15-23 weeks), in 2 premature infants of 34 and 36 weeks gestation and in 2 fullterm stillborn infants. There was no convincing evidence of fibre type differentiation in the masticatory muscles before 22 weeks' gestation while a fairly distinct differentiation was seen in biceps brachii specimens at 16 weeks' gestation with ATPase at pH 4.35. Around 22 weeks two types of fibre were found in all specimens with ATPase at pH 4.35. With regular ATPase (pH 9.4) there was a relatively weak difference in staining between different types of fibre in the masticatory muscles. In biceps brachii Type I and Type II were demonstrated. Neonatally 3 levels of staining were seen in biceps brachii with regular ATPase (pH 9.4); while ATPase pH 4.35 and 4.6 demonstrated the subtypes IIB and IIC. In the masticatory mucles only 2 levels were recognized with regular ATPase and all type II fibres had the characteristics of Type IIC as seen with with ATPase at pH 4.35.

Adenosine Triphosphatases↗

Temporal summation in muscles and referred pain areas: an experimental human study.

The aim of the present study was to assess temporal summation within saline-induced, localized and referred muscle pain areas. The sensibility to single and repeated electrical stimuli were assessed in the muscle by means of needle electrodes and in the referred pain area by surface stimulation. The study demonstrates that temporal summation of nociceptive input from muscles exists and that the responses to single and repeated nociceptive stimuli of the referred pain area are facilitated.

Electric Stimulation↗

Temporal patterns of muscle activation for arm movements in three-dimensional space.

Little is known about the patterns of muscle activation that subserve arm movement in three-dimensional space. In this study, activation patterns of seven arm muscles were related to the spatial direction of human arm movement. Twenty movement directions defined two orthogonal vertical planes in space. The arm movements were moderately paced; each movement lasted approximately 500 msec. New techniques of EMG analysis were developed to describe the temporal pattern of muscle activation. For each muscle, a principal component analysis revealed a common phasic and tonic waveform for all directions of movement, within one plane. A temporal shifting procedure based on best covariance values revealed activation delays associated with different movement directions. The results show a consistent pattern of temporal shifting of the common waveform for movements in different directions. Coupled with past results showing that activation amplitude is a function of the cosine angle of movement or force direction, the present results suggest a relatively simple control strategy for mechanically complex arm movements: neural circuits produce a common phasic and tonic activation waveform that is scaled in amplitude and delayed in time, depending on the desired movement direction.

Arm↗

Use of temporal fascia and muscle as an autograft.

A wide variety of materials have been used for reconstruction around the eyelids and orbit, including alloplastic materials, such as polyfilament surgical suture (Supramid), silicone, and Teflon, that have a tendency toward early infection or late extrusion. Preserved homografts, such as sclera or fascia lata, are unlikely to extrude but have variable absorption rates. Autografts have proved over the years to be the best, most reliable, and least reactive material for reconstruction. Our use of temporal fascia and muscule grafts has been quite successful.

Adult↗

Electromyography of masticatory muscles in three jaw registration positions.

The purpose of this study was to investigate whether anteroposterior changes in mandibular position affect masticatory muscle activity. The electromyographic (EMG) activity of masticatory muscles during full and partial (10%) clenching in three mandibular bite registration positions--retruded contact position (RCP), intercuspal position (IP), and muscular position (MP)--was studied. Three groups of subjects with different ranges of anteroposterior positioning of the condyles were evaluated (normal occlusion, Class II, Division 2 malocclusion, and dual bite malocclusion). A posterior stabilizing splint for each registration position was made. EMG data were obtained from three bilateral muscles (masseter, anterior temporal, and posterior temporal). Clenching in the RCP elicited the lowest masseter muscle activity during full clenching, and the highest anterior temporal and posterior temporal muscle activity during partial clenching. If the relationships of the masticatory muscles are analyzed through a ratio that represents the interaction between biting and positioning muscles (masseter/posterior temporal muscle ratio), the RCP as compared with other positions had the lowest ratio. The RCP required more positioning muscle activity and permitted less biting muscle activity. There was no significant difference in the muscle activity between the IP and MP registrations. Small changes in jaw position (anterior to RCP) are not critical for the masticatory apparatus provided there is good intercuspation. The results of this investigation suggest that intercuspation in RCP is not the optimal position.

Adolescent↗

Possible mechanisms of muscle cramp from temporal and spatial surface EMG characteristics.

In this study, the initiation and development of muscle cramp are investigated. For this, we used a 64-channel surface electromyogram (EMG) to study the triceps surae muscle during both cramp and maximal voluntary contraction (MVC) in four cramp-prone subjects and during cramp only in another four cramp-prone subjects. The results show that cramp presents itself as a contraction of a slowly moving fraction of muscle fibers, indicating that either the spatial arrangement of the motoneurons and muscle fibers is highly related or that cramp spreads at a level close to the muscle. Spectral analyses of the EMG and peak-triggered average potentials show the presence of extremely short potentials during cramp compared with during MVC. These results can also be interpreted in two ways. Either the motoneurons fire with enlarged synchronization during MVC compared with cramp, or smaller units than motor units are active, indicating that cramp is initiated close to or even at the muscle fiber level. Further research is needed to draw final conclusions.

Adult↗

Lumbar epidural fentanyl: segmental spread and effect on temporal summation and muscle pain.

BACKGROUND: Despite extensive use, different aspects of the pharmacological action of epidural fentanyl have not been clarified. We applied a multi-modal sensory test procedure to investigate the effect of epidural fentanyl on segmental spread, temporal summation (as a measure for short-lasting central hyperexcitability) and muscle pain. METHODS: Thirty patients received either placebo, 50 or 100 micro g single dose of fentanyl epidurally (L2-3), in a randomized, double-blind fashion. Heat pain tolerance thresholds at eight dermatomes from S1 to fifth cranial nerve (assessment of segmental spread), pain threshold to transcutaneous repeated electrical stimulation of the sural nerve (assessment of temporal summation) and pain intensity after injection of hypertonic saline into the tibialis anterior muscle (assessment of muscle pain) were recorded. RESULTS: Fentanyl 100 micro g, but not 50 micro g, produced analgesia to heat stimulation only at L2. Surprisingly, no effect at S1 was detected. Both fentanyl doses significantly increased temporal summation threshold and decreased muscle pain intensity. CONCLUSIONS: The findings suggest that a single lumbar epidural dose of fentanyl should be injected at the spinal interspace corresponding to the dermatomal site of pain. Increased effect on L2 compared with S1 suggests that drug effect on spinal nerve roots and binding to opioid receptors on the dorsal root ganglia may be more important than traditionally believed for the segmental effect of epidurally injected fentanyl. Epidural fentanyl increases temporal summation threshold and could therefore contribute to prevention and treatment of central hypersensitivity states. I.M. injection of hypertonic saline is a sensitive technique for detecting the analgesic action of epidural opioids.

Adult↗

Histochemical enzyme profile of the masseter, temporal and lateral pterygoid muscles of the European hedgehog (Erinaceus europeaus).

In man, there are large differences in histochemical fibre-type composition, distribution and size between jaw and trunk muscles, probably related to the special functions of the human stomatognathic system. In the hedgehog, the influence of alkaline and acid pre-incubations on the reaction for myofibrillar ATPase was different from that in man, suggesting a different myosin structure; the fibre composition was different also. The masseter, the superficial portion of the temporal and the lateral pterygoid muscles all showed a homogeneous fibre type profile with almost 100 per cent alkali-stable fibres. In two animals, the deep temporal muscles showed an apparent heterogeneous fibre pattern with 81 per cent alkali-stable fibres, 4 per cent alkali-labile fibres and 15 per cent ATPase-intermediate fibres; in one animal 87 per cent alkali-stable fibres and 13 per cent ATPase-intermediate fibres. There was no difference in cross-sectional area between the three fibre types within each muscle, but the fibres of the lateral pterygoid were smaller than the alkali-stable and the alkali-labile fibres of the masseter and temporal muscles. The limb and trunk muscles showed reactions for myofibrillar ATPase similar to the jaw muscles, but had a heterogeneous fibre-type profile. There was no significant difference in cross-sectional fibre area between the jaw and the limb muscles. Thus the jaw and limb muscles of the hedgehog have similar fibre types and about equal fibre size.

Adenosine Triphosphatases↗

Postnatal myosin heavy chain isoforms in prenatal porcine skeletal muscles: insights into temporal regulation.

Our knowledge of the temporal expression of postnatal (adult) fast myosin heavy chain (MyHC) isoforms (2a, 2x, and 2b) in prenatal muscles is limited. Using the pig as a target species and large-animal model, we report on the qualitative and quantitative expression of the major post- and prenatal MyHC isoforms during gestation, as determined by TaqMan real-time PCR and immunohistochemistry. We found that postnatal fast MyHC mRNAs and proteins were expressed much earlier in the pig (gestation day 35) than was previously reported in small mammals. There was a high degree of coexpression and colocalisation of pre- and postnatal MyHC mRNAs and proteins in prenatal muscles. During a period of prenatal muscle growth (gestation days 35-77), relative expression of MyHC isoforms (embryonic > 2a > 2x > 2b) correlated with the gene order in the skeletal MyHC cluster, which suggests the possible presence of cis-acting elements on the same side as the MyHC embryonic gene associated with temporal regulation.

Animals↗

Associations between anterior temporal, masseter, and orbicularis oris muscle activity and craniofacial morphology in children.

In a sample of children with Class I (n = 18), Class II, Division 1 (n = 25) and Class II, Division 2 (n = 12) malocclusions, the relationship between jaw muscle activity and specific craniofacial variables has been quantified. Muscle data were obtained from the temporal, masseter, and orbicularis oris muscles at rest, in maximum intercuspation, and during clenching, jaw opening, and swallowing. Contrasts in means of the three skeletal groups identified differences in both the craniofacial and muscle variables. Orbicularis oris muscle amplitude was greater at rest and in maximum intercuspation in Class II, Division 2 subjects. Anterior temporal amplitude during clenching was significantly lower in Class II, Division 1 subjects. A principal component analysis reduced the data base, and three canonical correlations were identified at the 0.05 level of significance. Significant canonical correlations could not be found between the cephalometric data and clench, swallow, or jaw-opening tasks, which suggests no dependency between these factors. Two canonical correlations were found for the rest position data. A linear combination of masseter and orbicularis oris activity and incisor separation was correlated (r1 = 0.758) with a linear combination of mandibular unit length, upper and lower central incisor angulation, and SNOP. The second rest canonical correlation (r2 = 0.733) involved the anterior temporal muscle and a series of sixteen cephalometric variables. For the maximum intercuspation data, orbicularis oris amplitude was correlated with a linear combination of upper incisor angulation and SNOP variables (r1 = 0.727). The multivariate statistical analysis extracted a clinically significant association between orbicularis oris muscle activity and incisor position.

Cephalometry↗

[Evaluation of the usefulness of vascularized bone grafts for surgical reconstruction of the face].

The process of healing of vascularised bone grafts was examined clinically and the use of vascularised bone grafts in face reconstruction surgery was assessed basing on author's experience with the surgical technique, availability of graft recipient and donor sites and final outcome. Patients enrolled in this study were treated at the Department of Maxillofacial Surgery, Pomeranian Academy of Medicine in Szczecin, for cancer, injuries, developmental anomalies and atrophic changes. In each case it was necessary to restore facial bone structures of functional and aesthetic importance, including: floor of the orbital cavity, alveolar process of maxilla, palate, malar bone and mandible (Tab. 2). Reconstruction was done mostly with parietal bone grafts pedicled on temporal fascia and muscle, coronoid process of the mandible pedicled on temporal muscle, and lower part of the diaphysis of mandible pedicled on masseter and pterygoid muscles. In some cases, reconstruction material consisted of a rib on greater pectoral muscle, clavicle on sternocleidomastoid muscle and scapular bone crest pedicled on trapezius muscle. Free microvascular flaps with some elements of fibula and radius were used in two patients for the reconstruction of mandible and soft tissues. In total, 41 vascularised grafts were performed in 40 patients. Graft healing was examined clinically and usefulness of this technique for face reconstruction surgery was assessed basing on author's experience with the preparation technique, intraoperative complications and extent of trauma to donor sites. The results of healing of specific grafts are enclosed in Table 1. The surgical technique for graft preparation and its transfer into the recipient site varied from case to case. The most difficult and effortful approach was with free bone grafts transferred from remote sites by means of a microsurgical technique (group V). Despite the complexity of the reconstruction method, no intraoperative complications occurred in the course of preparation of the radial and fibular bone grafts. In group IV, the most difficult grafts included those taken from ribs, clavicle and scapular bone. Parietal bone grafts were much less troublesome (subgroups Ia and Ib) although associated with the largest number of intraoperative complications. The easiest preparation method applied to the grafting of coronoid process and lower part of the body of mandible (group II and III). Clinical evaluation of vascularised bone grafts confirmed without reservations the value of this approach in face reconstruction surgery. However, the extent to which individual graft types proved to be usable varied. The most valuable ones included parietal bone grafts pedicled on temporal muscle and fascia used for restoring upper and central facial structures and the coronoid process of mandible pedicled on temporal muscle used for reconstructing the floor of the orbital cavity and alveolar process of the maxilla. Rib grafts pedicled on pectoral muscle were of limited use. The same applies to grafts from the lower part of the body of mandible pedicled on masseter and pterygoid muscles occasionally used for restoring the mental part of mandible. Grafts from remote sites (fibula, radius) should be used only when other reconstruction methods are unavailable.

Bone Transplantation↗

Feeding-induced changes in temporal patterning of muscle activity in the lobster stomatogastric system.

In the lobster Homarus gammarus, rhythmic masticatory movements of the foregut gastric mill are generated by a small neural network in the stomatogastric ganglion. We have used EMG recordings from intact animals to analyse gastric network output in relation to cycle period before and after feeding. In pre-prandial conditions, muscles controlling lateral teeth closure and medial tooth protraction (driven by MG and GM motor neurons, respectively) express relatively constant, return stroke-like burst durations, but change to a variable-duration power stroke-like phenotype after feeding. In contrast, the LPG neuron-innervated lateral teeth opener muscle switches from power stroke to return stroke-like behavior. Thus alternate phases within a single motor program may invert their temporal properties according to the behavioral situation.

Animals↗

The temporal/masseter co-contraction: an electromyographic and clinical evaluation of short-term stabilization splint therapy in myogenous CMD patients.

The short-term effect (3-6 weeks) of the use of a stabilization splint was investigated in a group of 35 myogenous craniomandibular disorder patients. The patients were clinically examined and surface EMG recordings of the temporal and masseter muscles were made during clenching in the intercuspal position (ICP), immediately after the insertion of the splint (SSP), and after at least 3 weeks of splint treatment (SSP 3). With the use of the error variance of the activity index changes in EMG activity were investigated. Three groups of patients were then recognized. One group showed a decrease in temporal muscle activity during splint treatment. Another group did not show any significant change during splint treatment. The third group showed an increase of temporal muscle activity. In general, significant reductions in the amount of static pain were found. In the group with a significant reduction of temporal muscle activity (n = 15) there was a greater decrease in the amount of static pain (P < 0.05) than in the group (n = 4) with a significant increase of temporal muscle activity. The results may indicate that the temporal muscle plays an important role in the perception of static pain in the masticatory system.

Adolescent↗

Effect of selection for growth rate on myosin heavy chain temporal and spatial localization during turkey breast muscle development.

The temporal and spatial localization of the heavy chain fast form of myosin was studied during turkey pectoralis major muscle development in a randombred control line (RBC2), a subline (F) of RBC2 selected only for increased 16-wk BW, a commercial sire line (B), and reciprocal crosses of the F and B lines. Pectoralis major muscle samples were obtained from three females and three males from each group in a manner to avoid contraction. After fixing and sectioning, the muscle samples were stained with a monoclonal antibody to determine the temporal and spatial localization of the heavy chain fast form of myosin. The percentage of muscle fibers at 25 d of incubation and 1 wk posthatch expressing the fast form of myosin heavy chain was calculated. The average percentage of muscle fibers expressing the fast form of myosin heavy chain for all genetic lines combined at embryonic d 25 for males was 76.1 and for females 66.6, whereas at 1 wk posthatch the average percentage for males was 24.2 and 36.1 for females. No interaction of sex and genetic group was noted at either age. At 25 d of embryonic development and at 1 wk of age, additive and nonadditive genetic effects were important in the inheritance of the fast form of myosin heavy chain. Heterosis was negative at both ages but significant at 1 wk of age. By 4 wk posthatch, all the muscle fibers in each genetic group were expressing the myosin heavy chain fast form, and no sex differences were observed. At 16 wk posthatch muscle fiber fragmentation was noted in the samples having reduced endomysial spacing. In the fragmenting muscle fiber areas, expression of the heavy chain fast form of myosin was observed. These muscle fiber changes were predominant in the growth selected F-line suggesting that growth selection may be associated with muscle damage.

Animal Husbandry↗