The landmark for removal of sialoliths using sialendoscopy alone in parotid gland sialolithiasis

Objective

To assess the general guidelines for removal of sialoliths in parotid gland sialolithiasis using sialendoscopy alone.

Intramuscular hemangioma of the masseter muscle: its characteristic appearance on magnetic resonance imaging.

A 10-year-old girl presented with a 6-month history of right facial swelling. Magnetic resonance imaging (MRI) revealed a tumor in the masseter muscle. On exploration through a preauricular incision, a vascular mass was found located in the lateral aspect of the right masseter muscle. The characteristic MRI appearance of the intramuscular hemangioma of the masseter muscle is shown and the value of MRI for a preoperative differential diagnosis is discussed.     

The influence of the masticatory muscles on craniofacial growth. A microsurgical study in the rat

Possible influence of masticatory muscles on facial growth was investigated in the rat by the formation of several experimental groups: excision of right masseter muscle of right temporal muscle, of both masseter muscles, of both temporal muscles and of both masseter and temporal muscles, section of inferior maxillary nerve and masseter transplantation. Results demonstrated that overall masticatory muscles provided equilibrium of masticatory function, any rupture of this equilibrium producing effects on mandibular growth and that of the facial mass.     

Reflex responses in human jaw, lip, and tongue muscles elicited by mechanical stimulation

Reflex responses in human jaw, lip, and tongue muscles were elicited with brief, innocuous mechanical stimuli. Stimuli were applied to the masseter (and overlying tissue), the lower lip vermilion, and the tongue dorsum. Reflex responses occurred in masseter, orbicularis oris inferior, and genioglossus muscles upon direct stimulation of the sites associated with each of these muscles. In contrast, reflex responses to stimulation of "distant" sites occurred almost exclusively in masseter; that is, stimulation of the lip and tongue produced responses in masseter, but, stimulation of jaw muscle spindle afferents and overlying cutaneous receptors had no observable effect on activity in genioglossus or orbicularis oris inferior muscles. It could be hypothesized that the motoneuron pools controlling jaw muscles are more sensitive to synaptic inputs generated by reflex pathways originating in other structures. The sensitivity of the masseter muscle to inputs from the lip and tongue may serve to link these structures functionally.     

Hematic cyst of the masseter. Apropos of 2 cases

An isolated swelling of the masseter raises an aetiopathogenic problem which may be encountered by any stomatologist. There are a number of diagnostic possibilities, in particular tumours. The authors report two cases with a special clinical picture: hematic cyst of the masseter. Treatment is surgical: excision via an endobuccal approach. Histological examination of the operative specimen reveals vascular dystrophy.     

蒂在后的颈阔肌肌皮瓣修复腮腺咬肌区皮肤组织缺损

目的探讨蒂在后的颈阔肌肌皮瓣修复腮腺咬肌区皮肤组织缺损的方法及可行性。方法回顾性总结2006～2007年间应用蒂在后的颈阔肌肌皮瓣修复腮腺咬肌区皮肤组织缺损共计6例。并就肌皮瓣的血供、设计、术中注意事项及术后效果进行了研究。结果本组6例随访2个月～1年,皮瓣全部成活,肌皮瓣术后的色泽、质地与面部皮肤较匹配,修复容貌效果满意。结论颈阔肌肌皮瓣血运丰富,成活率高,手术操作简便,是修复腮腺咬肌区皮肤组织缺损行之有效的方法,值得推广。     

Intramuscular hemangioma of the masseter muscle

Intramuscular hemangiomas (IMH) are uncommon tumors of the head and neck, but often occur in the trunk and extremities. When present in the head, the masseter muscle is the most frequently involved site, although constituting only 0.8% of all hemangiomas. Accurate preoperative diagnosis is uncommon without cytology or biopsy. A case of IMH of the masseter muscle in a 24-year-old Turkish woman is presented. Clinical, radiologic and histologic findings and treatment modalities are reviewed. Received: 5 March 1998 / Accepted: 7 August 1998     

Electrical activity of the masseter during swallowing after total laryngectomy

Total laryngectomy is a surgical procedure that can change swallowing biomechanics, including muscle activity of the masseter; this muscle stabilizes the mandible.AimTo characterize the electrical activity of the masseter muscle during swallowing after total laryngectomy. Series study.Material and MethodsAn electromyographic evaluation of swallowing was carried out; three different volumes of water (14.5ml, 20ml and 100ml) were swallowed, and there was a rest condition. The electromyographic signal was normalized by Maximum Resisted Voluntary Activity - considered as 100% of electrical activity of muscles. All other values were calculated as a percentage of this parameter.ResultsThere is moderate electrical activity of the masseter during swallowing with higher averages on the left. There was no difference between swallowing 14.5ml or 20ml. Natural swallowing of 100ml had the lowest average. Electromyographic signals were recorded at rest on both sides, indicating the existence of electric activity in this situation.ConclusionPatients submitted to total laryngectomy present electrical activity of the masseter muscles during swallowing and at rest. This activity is influenced by the volume of swallowed liquid, and showed significant differences among the tasks. Clinical Trials: NCT01095289     

Induction of regional collateral sprouting following muscle denervation

OBJECTIVES/HYPOTHESIS: Anecdotal clinical findings suggest that denervated muscle may regain modest functional recovery via spontaneous collateral sprouts from intact adjacent nerve fibers. The current study evaluates the conditions needed for the denervated masseter muscle to induce axonal sprouting from the facial nerve. We hypothesize that epineurial injury is required to induce collateral sprouting toward a neighboring denervated muscle. STUDY DESIGN: Twelve thy1-yellow fluorescent protein-16 (thy1-YFP-16) transgenic mice whose axons express yellow fluorescent protein were allocated into six groups, with four degrees of facial nerve injury (intact, crush, transection, removed segment) with or without masseter denervation. METHODS: Animals underwent serial in vivo imaging analyses under the fluorescent microscope weekly for 5 or 7 weeks and were subsequently perfused for analysis. Masseter muscle acetylcholine receptors (AChRs) were stained with Alexa Fluor 594 conjugated alpha-bungarotoxin, and whole mounts were imaged with confocal microscopy. RESULTS: In groups with intact or crushed facial nerves, no evidence of collateral sprouting was demonstrated. Mice with transected facial nerve branches or removed segments demonstrated sprouting from the proximal stump into the denervated masseter. Staining of the AChRs confirmed that new neuromuscular junctions were established between the facial nerve and the denervated masseter. CONCLUSIONS: This study suggests that epineurial injury is required to stimulate axonal sprouting into adjacent denervated muscle. Nerves with compromised epineurium may be useful in promoting neo-neurotization after muscle denervation.     

Intramuscular hemangioma of masseter muscle with prominent formation of phleboliths: a case report

A 14-year-old girl was referred for evaluation and management of progressive, painful swelling of the right cheek. Swelling had been present since 3-year old and had gradually increased in size. Magnetic resonance imaging (MRI) revealed a well-circumscribed, brighter mass in the right masseter muscle with numerous rounded areas of signal hypointensity. Preoperative diagnosis was intramuscular hemangioma of the masseter muscle and surgery was performed. The tumor was completely removed except for a few, small phleboliths. Pathological examination of resected tissue led to a high suspicion of cavernous hemangioma with phlebolithiasis. Nine months postoperatively, the patient developed another painful mass in the right masseter muscle. MRI indicated recurrent hemangioma and further surgery was performed. Careful exploration resulted in completely removal of residual phleboliths accompanied with fibroadipose tissue. Part of the buccal branch of the facial nerve was excised to achieve complete resection of the lesion. Histological examination revealed distinct venous formation in phleboliths adjacent to fibroadipose tissue, demonstrating that both phleboliths and feeding vessels had been left by the previous operation. The present report reviews the literature on intramuscular hemangiomas of the masseter muscle, and discusses diagnostic methods and optimal surgical treatment.     

Succinylcholine-induced masseter muscle rigidity during bronchoscopic removal of a tracheal foreign body

Masseter muscle rigidity during general anesthesia is considered an early warning sign of a possible episode of malignant hyperthermia. The decision whether to continue or discontinue the procedure depends on the urgency of the surgery and severity of masseter muscle rigidity. Here, we describe a case of severe masseter muscle rigidity (jaw of steel) after succinylcholine (Sch) administration during general anesthetic management for rigid bronchoscopic removal of a tracheal foreign body. Anesthesia was continued uneventfully with propofol infusion while all facilities were available to detect and treat malignant hyperthermia.     

豚鼠前庭下神经及三叉神经下颌支部分传入神经切断对声诱发咬肌反射的影响

目的:研究麻醉豚鼠前庭下神经及三叉神经下颌支部分传入神经切断对声诱发咬肌反射的影响。方法:20只豚鼠随机分成4组,正常对照组5只,单侧前庭下神经切断组5只,单侧下牙槽神经切断组5只,单侧耳颞神经切断组5只。4组动物分别进行Click声刺激诱发的咬肌反射检测。结果:正常对照组声诱发咬肌反射电位的负波(NP)阈值为(90.00±8.16)dBnHL。100、90、80、70 dBnHL单侧声刺激,同侧记录咬肌反射NP的引出率分别为100%、70%、40%、0。100、90、80 dBnHL单侧声刺激咬肌反射NP潜伏期分别为(6.55±0.25)ms、(6.61±0.16)ms、(6.70±0.13)ms。不同刺激强度,咬肌反射NP的潜伏期无明显差异(P>0.05)。单侧前庭下神经切断,术侧声诱发的咬肌反射消失。单侧下牙槽神经及耳颞神经切断组,术侧咬肌反射存在,NP的阈值、潜伏期与正常对照组无明显差异(P>0.05)。结论:声诱发的咬肌反射是前庭起源,不受三叉神经下颌支耳颞神经及下牙槽神经传入纤维的影响。     

改良腮腺浅叶切除术治疗腮腺良性肿瘤

目的 探讨腮腺良性肿瘤切除术中保留腮腺咬肌筋膜、耳大神经和腮腺导管对降低术后并发症的作用.方法 回顾性分析56例腮腺良性肿瘤行肿瘤切除术的患者,保留腮腺咬肌筋膜、耳大神经和腮腺导管,术后予负压引流和局部加压包扎,观察并发症的发生率.结果 所有患者术后均随访,无1例复发.3例患者发生面神经损伤,均为一侧口角略歪斜,鼓腮稍...     

Stimulation variables in electroneurography of the facial nerve

Electroneurography is an electrophysiologic measurement of compound action potentials elicited by the supramaximal stimulation of a peripheral nerve. The stimulus intensity-response function was examined in the cat facial nerve following stimulation over two different sites of the facial nerve: the main trunk and the buccal branches. Thresholds were achieved at lower current settings, the resultant compound action potential exhibited a greater amplitude, and masseter muscle excitation was more evident following stimulation over the buccal region. The use of concurrent facial- and masseter-evoked electromyographic monitoring allows more sensitive detection of masseter excitation and a more accurate determination of the current level necessary for supramaximal stimulation.     

Provocable tumor of the cheek as a manifestation of so-called "infiltrating lipoma" of the masseter muscle]

We report on a 29-year-old male patient, who presented at our outpatient clinic with a 6-year history of progressive swelling of the right cheek. Contraction of the masseter muscle increased the swelling. MR-Imaging revealed a tumor measuring 2 x 3 cm, which was located within the masseter muscle. The histological diagnosis was infiltrating lipoma, which to our knowledge has not been described in this area before. This particular type of lipoma is extremely rare in the head and neck. The diagnostic and therapeutic management of infiltrating lipoma is discussed, and guidelines for adequate follow-up suggested. In addition, the authors review other sites of this tumor and describe its histological characteristics and differential diagnosis.     

The influence of tonsillitis on oral and throat muscles in children

OBJECTIVES: Surface electromyography (sEMG) studies were performed on 80 children with acute tonsillitis (AT) and 110 children with recurrent tonsillitis (RT), age 4-12 years, to trace sEMG changes of duration and amplitude of muscle activity during swallowing and continuous drinking. STUDY DESIGN: Prospective observational study of randomly chosen patients compared to normative database. METHODS: Timing and amplitude (in muV) of activity of masseter, submental and infrahyoid muscles were evaluated during voluntary single swallows of saliva ("dry" swallow), water swallows, swallows of excessive amount of water (up to 15 ml), and continuous drinking of 50 ml of water. These parameters were measured for two age groups for both conditions: 4-8 and 9-12 years old. The previously established normative database was taken for control. RESULTS: AT presents prolonged duration of swallowing and electric hyperactivity of infrahyoid muscles but this activity returns to normal after recovery. RT affects masseter and infrahyoid muscles even during periods of remission but do not affect duration of swallowing activity. CONCLUSION: AT and RT in children age 4-12 years affects muscle activity during swallowing significantly by involving additional muscles (mainly infrahyoid) in this process. AT presents temporary electric hyperactivity of infrahyoid muscles. RT affects masseter and infrahyoid muscles even during periods of remission (pathologic changes are fixed). Abnormally high electric activity of masseter and infrahyoid muscles in patients with RT might serve as an additional indicator for tonsillectomy. Surface EMG of swallowing is a simple, non-invasive and reliable method for diagnostic and preoperative evaluation of dysphagia complaints associated with tonsillitis.     

Otalgia as a result of certain temporomandibular joint disorders

INTRODUCTION: Different hypotheses of reasons for common incidence of temporomandibular disorders (TMD) and otalgia have been discussed. The hypothesis of this study was, that the high prevalence of otalgia in patients with TMD may result in part from pain in the M. masseter pars prof. or in the temporomandibular joint (TMJ) which, due to the close anatomic neighborhood, can feel like ear pain. MATERIAL AND METHODS: [corrected] We retrospectively analyzed the anamneses of 720 of our TMD-patients with regard to main treatment motivation: how many patients quoted "pain in the ear" as main treatment motivation and how many of them had no objective findings in the ear but muscle tenderness of the M. masseter prof. or objective findings in the TMJ. Using all pairwise multiple comparison procedures (Dunn's Method) we compared the frequency of muscle and joint findings in patients with ear complaints to two controls: Tinnituspatients and patients seeking orthodontic treatment. RESULTS: 51 of 720 patients quoted ear pain as main treatment motivation. 25 of them (49 %) had findings in the masseter muscle, 9 (18 %) in the joint and 15 (29 %) had findings in both the joint and the muscle. The frequency of findings in the controls was significantly (p < 0.001) lower. CONCLUSION: A significant fraction of patients seeking treatment due to pain in the ear have no findings in the ear, but in the TMJ and in the masseter muscle.     

Intramasseteric schwannoma in a child

Schwannoma arising in muscle is rare. We treated a very unusual case of schwannoma originating in the masseter muscle in a 12-year-old boy, who presented with a 1-year history of a painless left cheek mass. CT and MRI revealed that the mass existed in the masseter muscle. It was extirpated under general anesthesia without postoperative sequelae. The whitish mass was solid and encapsulated, and pathologic examination confirmed the diagnosis of schwannoma consisting of Antoni A and Antoni B areas. Definitive diagnosis of schwannoma before surgery is usually difficult; hence, histological examination during or after surgery is, in most cases, decisive. However, schwannoma should be considered in the preoperative differential diagnosis of intramuscular tumor, despite its rare occurrence, since postoperative neurological sequelae may occur.     

Intramasseteric metastasis of renal cell carcinoma

In this case report, we present a solitary metastasis of renal cell carcinoma inside the masseter muscle. To our knowledge, it is the very first case ever encountered.     

The effects of masseter tendon vibration on nonspeech oral movements and vowel gestures.

The role of proprioception in speech and oral motor control was investigated by applying tendon vibration to the masseter during vowel production and nonspeech oral movements. Measures were made of peak jaw-opening amplitude, jaw-opening velocity, and movement time in both vibration and nonvibration conditions. Generally, the tendon vibration caused a consistent and marked reduction in the amplitude and velocity of jaw-opening movements for each subject in both tasks. Movement time remained consistent across the vibration conditions for both tasks. These results indicate that masseter tendon vibration causes significant changes in jaw kinematics during simple speech gestures and nonspeech movements. These findings are consistent with the documented effects of tendon vibration on limb movements. The study demonstrates that tendon vibration is a potent tool for investigating proprioception in speech and oral motor control.