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The purpose of this paper is to present the clinical, radiographic, and histological aspects of a case of traumatic myositis ossificans of the temporal muscle. This is a rare, benign ossifying pseudotumor of skeletal muscles. It had developed 3 weeks after trauma to the left temple in a 33-year-old man. Differential diagnostic aspects of traumatic myositis ossificans confirming its benign character are discussed.
Electromyographic records from the temporal and masseter muscles of 19 edentulous patients were made, before and 30 days after wearing complete dentures. The purpose of this study was to determine the electromyographic changes: The amplitude of electromyographic records from de temporal muscles decreased, while those from the masseter muscles increased. These results suggest that the use of complete denture provokes electromyographic changes by increasing the occlusal vertical dimension and, thus, periodical electromyographic records from temporal and masseter muscles could be useful for determining the time for complete denture change.
This report describes the case of a patient with congenital bilateral facial paralysis in whom ectopic bone formation developed following temporal muscle transposition. Ectopic bone formation was first noticed 4 years after surgery. Whether the ossification is a result of the transfer of periosteum or the osteogenic capacity of muscular tissue is still unknown.
This study applied frequency analysis to compare changes in the power spectrum density functions of surface electromyograms obtained from the paired masseter and anterior temporal muscles during therapy with three types of functional appliances, namely the Bionator, modified Fränkel type I, and Fränkel type III. Eighteen children were divided into three groups receiving either Bionator, Fränkel type I, or Fränkel type III therapy; a fourth group consisting of six children who received no therapy served as control. Before and after 3, 6, and 12 months of therapy, each child performed maximum voluntary isometric clenches in the position of maximum intercuspation. The mean frequency of the power spectrum was the variable studied. Children treated with the Bionator and Fränkel type I appliances showed greater changes in mean frequency than those treated with the Fränkel type III appliance. Although the muscles of untreated children also showed shifts of mean frequency to lower frequency values as a function of time, there was a greater downward shift of mean frequency in those treated with functional appliances. The downward shifts might have been associated with changes in muscle fiber lengths and/or recruitment patterns as a result of both treatment and normal growth.
The electromyographic background activity of the temporal muscle was observed after short-term detachment of the muscle and with increased loads on the mandible. Detachment of the muscle increased its mean spike discharge within the first 24 days but without significant changes in the spectral components. Loading the mandible decreased both the spike discharge and spectral components.
Fourteen patients with recurrent dislocation of the temporomandibular joint underwent surgical operation which consisted of Myrhaug's (1951) technique (resection of the articular tubercle and eminence). In 12 of these 14 cases, Myrhaug's technique was associated with redirectioning of the temporal muscle (Ullik and Zenker's (1961) technique). The simultaneous performance of both surgical procedures has been extremely useful in achieving a definite cure of recurrent dislocation of the temporomandibular joint.
10 young patients from 7 to 16 years of age with moyamoya disease were treated by temporal muscle graft (encephalo-myo-synangiosis: EMS) for the purpose of increasing extracranial and intracranial collateral circulation. Ischemic cerebrovascular symptoms and signs were encountered in all of them without intracranial hemorrhage. The patients were observed for 6-26 months after the first operation. Transient ischemic attacks disappeared in 4 out of 7 patients, and improved in frequency and duration in the remaining 3. Paresis of the limbs disappeared in 1 patient and improved in 2. In 2 patients, facial palsy disappeared and dysarthria improved as well. Ataxia disappeared in 2 patients, and involuntary movement of the extremities disappeared in 2. There were no ineffective cases clinically. In postoperative carotid angiography, the middle cerebral arteries were visualized clearly to the peripheral portion mainly via the thickened deep temporal arteries, and the abnormal vascular networks in the region of the basal ganglia reduced in size in most of patients. Improvements in intelligence quotient, electroencephalogram and cerebral blood flow were also obtained in several patients, respectively. EMS seemed to be an effective surgical treatment in young patients with moyamoya disease who suffered from cerebral ischemic symptoms.
Deaf individuals show a number of difficulties related to the functionality of the stomatognathic system, mainly by reason of the little or no use of facial musculature during speech either due to the use of sign language or to the difficulty that these individuals have in articulating words. The stomatognathic system muscles play important roles in functions such as mastication, deglutition, and phonation. This study aimed to assess, by means of computerized bilateral electromyography (EMG), masseter and temporal muscles of 12 oralized deaf individuals in clinical activities that involve part of this masticatory musculature and compare this system's functionality with that of 12 normal listening individuals, performing the same activities. An 8-channel K6-I EMG Light Channel Surface Electromyography device was used (Myo-Tronics Co.Seattle, WA, USA), in addition to disposable double electrodes covered with silver chloride (Duotrodes; Myo-tronics Co., Seattle, WA) containing a conductor gel (Myogel- Myo-tronics Co., Seatlle, WA). The averaged rectified EMG values were normalized with reference to the EMG amplitude induced by a maximum bite force. The statistical analysis confirmed that there were any significant differences between the groups, clinical activities, and muscles, and also effects of interaction among them. The analysis made use of Variance Analysis (ANOVA). Significant differences (p < 0.01) for both muscles were found among the clinical conditions, with deaf individuals showing greater electromyographic activity for both muscles for the clinical activity protrusion. Deaf individuals showed a lower muscular activity for clinical activities that demanded a greater masseter and temporal muscular activity such as mastication, mouth opening and closing, and dental compression. Greater electromyographic values were found for both deaf individuals and healthy controls during clinical activities of mastication and dental compression. Based on the obtained data, we concluded that deaf individuals showed a lower activity of the masticatory musculature than healthy individuals; the differences were significant at the level of p < 0.01 between the performed clinical activities; and all deaf individuals and healthy controls showed greater electromyographic values for mastication and dental compression.
Three dental nurses took part in an investigation of the reproducibility of the EMG silent period. The latency and duration of the silent period after tooth tapping and jaw jerk were found to be rather stable within the same day and between recordings every other day for 10 days. No differences in the SP variables between right and left side were found. Differences in the latency and duration of the silent period between the masseter and anterior temporal muscles during tooth tapping and jaw jerk were registered. The findings suggest functional difference between the two muscles.
Forensic dentistry plays an essential role in personal identification procedures. An adequate interincisal space of cadavers with rigor mortis is required to obtain detailed dental findings. We have developed intraoral and two directional approaches, for myotomy of the temporal muscles. The intraoral approach, in which the temporalis was dissected with scissors inserted via an intraoral incision, was adopted for elderly cadavers, females and emaciated or exhausted bodies, and had a merit of no incision on the face. The two directional approach, in which myotomy was performed with thread-wire saw from behind and with scissors via the intraoral incision, was designed for male muscular youths. Both approaches were effective to obtain a desired degree of an interincisal opening without facial damage.
The authors have for the first time achieved good results in experimental operations performed in 2 cadavers and 8 laboratory animals. A female patient suffering from progressive facial hemiatrophy was operated on with good results. The authors have revealed that facial deformation associated with Parry-Romberg's syndrome may be eliminated by myoplasty with the temporal muscle combined with transplantation of the allocartilage covered with perichondrium.
The periodontal mechanism that controls the jaw reflexes was examined in lightly anesthetized rats. Motor-unit activity in the masseter and temporal muscles was recorded electromyographically and pressure stimulation was applied to either an upper incisor or an upper molar. Reflex effects of dental stimulation varied depending on the level of ongoing activity (background activity, BGA) in each motor unit. Incisal or molar stimulation elicited excitatory reflexes in both the masseter and temporal motor units at a low BGA, but inhibitory reflexes in both types of motor unit at a higher BGA. In contrast to these synergistic reflex actions, the reciprocal reflex actions of the two motor units that belonged to the respective muscles occurred when the BGA was intermediate. The results suggest that different patterns of periodontal jaw reflexes may be elicited, depending on the different levels of BGAs. Furthermore, the present reflexes were modified with the site of a stimulated tooth within the dentition. Incisal stimulation produced greater excitation in the masseter motor unit than in the temporal one, and the opposite type of response occurred during molar stimulation. Moreover, smaller-amplitude motor units with a low reflex threshold and larger-amplitude motor units with a higher reflex threshold tended to exhibit excitatory and inhibitory reflexes, respectively.
Intramuscular lipomas are uncommon benign mesenchymal tumors which infiltrate skeletal muscle and are exceedingly rare in the head and neck region. Because of the infiltrating nature of the lesion and a high propensity for recurrence, they are sometimes difficult to distinguish from well-differentiated liposarcomas (WDLS). We report, the first case of an infiltrating lipoma of the temporal muscle in a 62-year-old white man who presented with a slow growing mass in the left temporal region. The histopathological examination showed diffuse infiltration of the striated muscle fibers by mature adipocytes. There were no lipoblasts or cells with atypical nuclei as described in WDLS. We performed interphase fluorescence in situ hybridization (FISH) analyses using painting probes for chromosome 12 and a specific probe for the MDM2 gene and comparative genomic hybridization. The results did not identify MDM2 or 12q amplification and therefore confirmed the benign nature of the lesion.
Although reflexes in human jaw muscles have been extensively studied, the neurotransmitters involved in the regulation of these reflexes are not well known. The aim of the present study was to investigate whether amitriptyline, a combined serotonin and noradrenaline re-uptake inhibitor, modulates the late exteroceptive suppression period (ES2) of temporal muscle activity in chronic tension-type headache. ES2 was recorded with a previously evaluated method and assessed by a blinded observer in 35 patients with chronic tension-type headache. Thereafter, ES2 was recorded in 27 of these patients during a double-blind, placebo-controlled, 3-way crossover trial investigating the prophylactic effect of amitriptyline, the selective serotonin re-uptake inhibitor citalopram, and placebo. ES2 duration was significantly shorter during treatment with amitriptyline than during placebo, P = 0.02, while ES2 duration only tended to be shorter during treatment with citalopram, P = 0.34. ES2 was not significantly correlated to the prophylactic effect of amitriptyline or to a range of clinical and experimental pain parameters. Our results demonstrate that amitriptyline reduces ES2 and indicate that ES2 is modulated by serotonergic as well as noradrenergic neuronal pathways.
1. The contractile properties of the motor units of the masseter and temporal muscles of human subjects were studied during voluntary isometric contractions, using a method previously employed to examine units of a small hand muscle. 2. Over the range of forces studied (0-6 kg), the units of both muscles were recruited in an orderly fashion, with a nearly linear relationship between the voluntary force at which units were recruited and their measured twitch tensions. 3. The range of contraction times (25-90 msec) was similar to that observed for the hand muscle. In some subjects it seemed that small units, recruited at low forces, exhibited shorter contraction times.
14 natural dentitioned subjects with no signs of TMJ disorders, aged 19-58, were used in this study. They were divided into three groups according to their occlusal guidance. One is canine guidance group (CG group), the other is group function group (GF group), and the last is group having non-working side contacts (FB group). All subjects were asked to perform maximum biting in 1) intercuspal position (IP), 2) right lateral position (rLP), 3) left lateral position (lLP), 4) retruded position (RP), and 5) protruded position (PP). EMG recordings of right and left masseter, anterior and posterior temporal muscles from pairs of surface electrodes were taken in each occluded position. The results were as follows: 1) Total integrated EMG activity of FB group was approximately equal in any occluded position, whereas that of CG and GF group varied from position to position. 2) EMG patterns in rLP and lLP of CG group were obviously different from those of GF group. Ratio to maximum biting in IP of CG group in rLP and lLP were significantly small, approximately half of GF group.
Orbital exenteration is a disfiguring operation that involves the total removal of the orbital contents with partial or total excision of the eyelids. Common methods of orbit reconstruction include pectoralis musculocutaneous pedicled flap and free tissue transfer. The purpose of this study is to illustrate that the entire temporalis muscle may be used by creating a large window in the lateral orbit, without resection of the lateral orbital rim. Orbital exenteration was performed on four cadavers. A window was created in the lateral orbit using a 4-mm pineapple burr. Three parameters were measured: (1) the distance between the zygomatic arch to the superior aspect of the temporalis muscle; (2) the width of the temporalis muscle; and (3) the length and width of the lateral orbit window. The free edge of the transposed temporal muscle was then sutured to the skin edge around the bony orbit. This procedure was then performed on a 73-year-old man who had undergone right orbital exenteration for ocular melanoma and then postoperative radiation. The dimensions of the bony windows in the cadavers were as follows: mean 3.3 cm (SD +/- 0.19 cm) x 1.9 cm (SD +/- 0.18 cm), n = 4. The dimensions of the temporalis muscle in the cadavers were the following: mean 8.45 cm (SD +/- 0.60 cm) x 10.5 cm (SD +/- 0.33 cm), n = 4. In the patient, the size of the bony window was 3.7 cm x 2.1 cm (n = 1), and the dimensions of the temporalis muscle were 8.1 cm x 10.2 cm (n = 1). The patient recovered well without complication, with a well-healed skin graft over the top of the muscle flap. An adequate bony window can be made to allow transfer of the entire temporalis muscle for orbital reconstruction without resecting the lateral orbital rim or entering the middle cranial fossa. This option is a good alternative to the other commonly performed methods of orbital reconstruction because of its completion in one operative stage, short operative time, and minimal donor site morbidity.
An electromyographic study was performed on 10 young growing girls in the age group of 9 to 12 years with Class II Division 1 malocclusion and retruded mandible, who were under treatment with Twin-block appliances. Bilateral EMG activity of elevator muscles of the mandible (ie, anterior temporalis and masseter) was monitored longitudinally with bipolar surface electrodes to determine changes in postural, swallowing, and maximal voluntary clenching activity during an observation period of 6 months. The changes were noted at the start of treatment (0 month), within 1 month of Twin-block insertion, at the end of 3 months, and at the end of 6 months. The results revealed a significant increase in postural and maximal clenching EMG activity in masseter (P <.01) and a numeric increase in anterior temporalis activity during the 6 month period of treatment. The increased electromyographic activity can be attributed to an enhanced stretch (myotatic) reflex of the elevator muscles, contributing to isometric contractions. The main force for Twin-block treatment appears to be provided through increased active tension in the stretched muscles (motor unit stimulation) and from initiation of myotatic reflex activity and not through passive tension (viscoelastic properties) of jaw muscles. The results of this study reaffirm the importance of full-time wear for functional appliances to exert their maximum therapeutic effect by way of neuromuscular adaptation.