Hakim AW, Dong XD, Svensson P, Kumar U, Cairns BE. TNF mechanically sensitizes masseter muscle afferent fibers of male rats. J Neurophysiol 102: 1551–1559, 2009. First published June 24, 2009; doi:10.1152/jn.00326.2009. Behavioral evidence in rats indicates that injection of tumor necrosis factor alpha (TNF ) into skeletal muscle results in a prolonged mechanical sensitization without gross inf...

Masseter muscle hypertrophy is a rare condition of idiopathic cause. It clinically presents as an enlargement of one or both masseter muscles. Most patients complain of facial asymmetry; however, symptoms such as trismus, protrusion, and bruxism may also occur. Several treatment options reported for masseter hypertrophy are present, which range from simple pharmacotherapy to more invasive surgi...

The myotonic response of the masseter muscles following various doses of suxamethonium was measured using a unique myotonometer in 50 apparently healthy patients, the majority of whom showed a myotonic response which lasted less than 100 s. A maximum increase in masseter tone was found to be greater than 1 kg in five patients, and 12 patients developed a maximum tone of greater than 500 g. An i...

BACKGROUND The aim of this study was to investigate the effect of a botulinum toxin type A (BTX-A) injection in the masseter muscle using electromyography (EMG) in an animal model. METHODS Ten male adult (>3 months of age) New Zealand white rabbits were used. Muscle activity was continuously recorded from 8 hours before to 8 hours after BTX-A injection. The rabbits received unilateral BTX-A i...

OBJECTIVES To estimate the association of initial masseter muscle thickness with treatment outcomes using functional appliances and the effect of treatment on masseter muscle thickness. MATERIAL AND METHODS Twenty-two children, aged 8-12, with skeletal and dental class II relationships and increased overjet were treated with twin-block appliances for 9-17 months, until a class I molar relatio...

The aim of this study is to evaluate muscle fatigue in the temporal and masseter muscles in patients with temporomandibular dysfunction (TMD). Two hundred volunteers aged 19.3 to 27.8 years (mean 21.50, SD 0.97) participated in this study. Electromyographical (EMG) recordings were performed using a DAB-Bluetooth Instrument (Zebris Medical GmbH, Germany). Muscle fatigue was evaluated on the basi...

The frequency content of the surface electromyogram (EMG) of the anterior temporal and masseter muscles of 14 normal adults was obtained during maximum clench in intercuspal position, as well as at different bite force levels. Frequency analysis was carried out by computer using a fast Fourier transform algorithm to obtain the power-spectral density function and the power spectrum of the EMG si...

We report a case of congenital fistula from ectopic accessory parotid gland to the cheek demonstrated by CT sialography and CT fistulography. The right parotid gland was abnormally located lateral to masseter muscle. The fistula was arising from an ectopic accessory parotid gland with ectopic duct positioned anterior to masseter muscle. CT sialography and CT fistulography were very helpful in t...

[Purpose] This study aimed to examine the effects of neuromuscular electrical stimulation on masticatory muscle activation in elderly stroke patients. [Subjects and Methods] The subjects included 20 elderly patients diagnosed with stroke and 10 healthy elderly individuals. The neuromuscular electrical stimulation group received stimulation on the masseter muscle in the affected side for 30 min ...

OBJECTIVE We aimed to evaluate by longitudinal neurophysiological examinations the natural course of masseter muscle weakness that developed after percutaneous balloon compression (PBC) of the trigeminal ganglion for the treatment of idiopathic trigeminal neuralgia. METHODS The affected side of 15 patients (mean age 69.5±4.5 years) who underwent unilateral PBC were studied before, 1 month, 6 ...