• The Journal of the Korean dental association
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• v.41 no.6 s.409
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• pp.450-454
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• 2003

The Purpose of this study is to report the effect botulinum toxin type A injection for the masseter hypertrophy patient with bruxism. Nine patients enrolled in this study were diagnosed as masseter hypertrophy associated with bruxism and the patients were injected with a 25U of botulinum toxin type A (BTXA:Lanzhou) to each masseter muscles. All nine patients showed marked reduction of masseter hypertrophy and eight patients reported the resolution of bruxism in 8 weeks after injection, with no significant complications. This preliminary study suggest that the botulinum toxin type A injection is an alternative method to treat the masseter hypertrophy with bruxism.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.30 no.5
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• pp.473-479
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• 2008

Asians tend to have prominent mandibular angle. The causes of wide lower third of the facial contour are obtuse mandibular angle and hypertrophy of masseter muscles. In cases of hypertrophy of masseter muscles, conventional treatment intends to the contraction of masseter muscle. Recently, volumetric reduction of masseter muscles using botulinum toxin type A injection and radiofrequency (RF) reduction have been introduced. The use of RF energy for masseter muscle reduction is known as a safe, simple, and effective method for aesthetic lower facial contouring. The purpose of this study is to present the effects of RF reduction applied to hypertrophy of masseter muscles, to review and to encourage RF practices in oral and maxillofacial region.

• Journal of Oral Medicine and Pain
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• v.41 no.1
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• pp.26-29
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• 2016

Intramuscular hemangioma is a rare type of hemangiomas and sometimes overlooked by orofacial pain specialist who encountered various types of masticatory muscle problems. A 42-year-old male, presented with feeling of unilateral hypertrophy on left mandibular area, is finally diagnosed as hemangioma with thrombus by excisional biopsy. However, he was initially treated by injection of botulinum toxin A due to misdiagnosis as unilateral masseter hypertrophy. In the present report, we remind the importance of careful examination and diagnostic images to orofacial pain clinicians in early detection of intramuscular hemangioma of masticatory muscles.

• Journal of Dental Rehabilitation and Applied Science
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• v.27 no.2
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• pp.247-251
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• 2011

Botulinum toxin type A (BoNT-A) is used for treating bilateral masseter hypertrophy since 1994. Recently there have been more clinical studies in this area, with some authors reporting that BoNT-A can reduce the size of the masseter muscle, as documented by photography, ultrasonography, computed tomography, and 3D(three dimensional) laser scan. However, earlier studies were only for bilateral masseter hypertrophy cases, not for unilateral masseter hypertrophy cases. The aim of this study was to use 3D laser scanning to evaluate changes in the external facial contour induced by unilateral BoNT-A injection. BoNT-A was injected into hypertrophic masseter muscle unilaterally in 10 patients with asymmetric masseter hypertrophy. The clinical effects of unilaterally injected BoNT-A were evaluated before the injection and 4, 8, and 12weeks after the injection using 3D laser scan. And the mean values of both sides (injection and non-injection sides) were compared with. At injection side, mean values of the volume and the bulkiest height at each time point diminished significantly between pre-injection and 4, 8, and 12weeks post-injection. At non-injection side, in contrast, mean values of the volume and the bulkiest height diminished also but less than that of injected side, and there was no statistical significance. In this limited study, we concluded that the unilaterally BoNT-A injection side showed greater mean values of the reduction of muscle volume than non-injection side at 4, 8, and 12 weeks after the injection.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.21 no.2
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• pp.215-219
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• 1999

This article discusses the diagnosis, anatomic consideration, and surgical management of masseter muscle hypertrophy. Surgical correction is advised for patients who have esthetic complaints. Esthetic improvement can be achieved by surgery and not by conservative treatment. Recently, the intraoral method, which leaves no scar on the face and minimizes the possibility of injury to the marginal branch of the facial nerve, has been supported by many surgeons. Patients who complained of marked swelling of unilateral or bilateral mandibular angle area and showed abnormal bony growth at the mandibular angle area and enlarged masseter muscle received mandibular angle shaving and excision of the inner layer of masseter muscle with intraoral approach. After operation, physiotherapy was done with EAST(eletrical acupuncture stimulation therapy) for encouraging the mouth opening and reducing the swelling. They showed early maximum mouth opening and reduction of swelling.

• Archives of Plastic Surgery
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• v.38 no.2
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• pp.173-181
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• 2011

Purpose: Masseter muscle is an important muscle of mastication. Because it has a great influence on the shape of low facial contour, patients who have masseteric hypertrophy show square-shaped jaw appearance. As aesthetic procedures for the reduction of the masseter muscle volume, radiofrequency ablation or botulinum toxin injection is at the center of attention. Authors studied the anatomical measurement of the thickness and width of masseter muscle and the surface mapping of the maximal thickness point using computed tomography (CT) scan to identify the useful guide for the injection of botulinum toxin in masseteric hypertrophy patients. Methods: We analyzed 2 mm-thickness OMU (ostiomeatal unit) CT of 112 normal people (224 masseter muscles) taken from June 2009 to May 2010. First, we measured the thickness, width and depth of the masseter muscle from the skin surface and analysed each by side, sex and age, respectively. The distribution of the thickness of the muscle and the correlation of thickness and width of the muscle were studied also. Second, we underwent surface mapping of the maximal thickness point using CT analysis by means of checking the vertical and horizontal distance from the angle of the mandible. Results: The average thickness and width of the masseter muscle was 17.73 mm and 40.78 mm in the male patients and were 14.33 mm and 37.42 mm in the female patients. Statistically, both figures of the male patients were larger than those of the female patients. However, the depth of the muscle from the skin surface in female patients (7.37 mm) was larger than that of the male patients (6.15 mm). There were no statistical difference in side or age. The width and thickness of the masseter muscle were in the positive correlation. The location of maximal thickness point of the masseter muscle was 27.77 mm vertically and 27.68 mm horizontally in the male patients, and 25.19 mm vertically and 25.42 mm horizontally in the female patients from the angle of mandible. Conclusion: We were able to present statistical evidence of the diagnosis and treatment of the masseteric hypertrophy regarding the anatomical measurements such as the thickness and width. And the maximal thickness point of the masseter muscle may be a useful guide for the clinical procedures of botulinum toxin injection.

• The Journal of the Korean dental association
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• v.15 no.3
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• pp.205-208
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• 1977

The etiology of masseteric hypertrophy is obscure. When the hypertrophy occurs unilaterally it's appearance is more striking because of the resultant facial asymmetry. Two soldiers were admitted with the complaint of a lump on their jaws. The authors obtained good results on the esthetic & functional aspect in two cases of unilateral masseteric hypertrophy with the Adam's method. The etiology was thought to be the combination of unilateral masticatory and jaw clenching habits when emotionally disturbed or under nervous tension in army services.

• The Journal of the Korean dental association
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• v.55 no.4
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• pp.303-309
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• 2017

Cosmetic use of botulinum toxin in the maxillofacial area has increased. Lower facial contouring is mostly performed procedure. Treatment of dynamic lines of the forehead, glabella, lateral orbit is also popular. Specific injection sites and clinical guidelines are presented.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.11 no.2
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• pp.74-80
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• 1989

Etiological manifestion of unilateral a bilateral hypertrophy of masseter muscle, is not cleanly defined. It thought to have a congenital combined with occlusion, psychogenic & neurophysiologic rances. The disease is cleanly differentiated from other disease, however careful distinction of the parotid disease is necessary due to its location. The patients mainly complaint aesthetic problems, surgical excision is the treatment of choice. Although no recurrence cases were reported, follow up for this is recommended.

• The korean journal of orthodontics
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• v.47 no.4
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• pp.222-228
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• 2017

Objective: To evaluate soft- and hard-tissue changes in the mandibular angle area after the administration of botulinum toxin type A (BoNT-A) injection to patients with masseteric hypertrophy by using three-dimensional cone-beam computed tomography (3D-CBCT). Methods: Twenty volunteers were randomly divided into two groups of 10 patients. Patients in group I received a single BoNT-A injection in both masseter muscles, while those in group II received two BoNT-A injections in each masseter muscle, with the second injection being administered 4 months after the first one. In both groups, 3D-CBCT was performed before the first injection and 6 months after the first injection. Results: Masseter muscle thicknesses and cross-sectional areas were significantly reduced in both groups, but the reductions were significantly more substantial in group II than in group I. The intergonial width of the mandibular angle area did not change significantly in either group. However, the bone volume of the mandibular gonial angle area was more significantly reduced in group II than in group I. Conclusions: The repeated administration of BoNT-A injections may induce bone volume changes in the mandibular angle area.