title: Painful unilateral temporalis muscle enlargement: reactive masticatory muscle hypertrophy.
abstract: An instance of isolated unilateral temporalis muscle hypertrophy (reactive masticatory muscle hypertrophy with fiber type 1 predominance) confirmed by muscle biopsy with histochemical fiber typing and image analysis in a 62 year-old man is reported. The patient presented with bruxism and a painful swelling of the temple. Absence of asymmetry or other abnormalities of the craniofacial skeleton was confirmed by magnetic resonance imaging and cephalometric analyses. The patient achieved symptomatic improvement only after undergoing botulinum toxin injections. Muscle biopsy is key in the diagnosis of reactive masticatory muscle hypertrophy and its distinction from masticatory muscle myopathy (hypertrophic branchial myopathy) and other non-reactive causes of painful asymmetric temporalis muscle enlargement.
authors.affiliation: Department of Pediatrics, Drexel University College of Medicine, Section of Neurology, St. Christopher's Hospital for Children, Philadelphia, PA, 19134, USA, ckatseto@drexelmed.edu.
authors.forename: Christos D
authors.initials: CD
authors.lastname: Katsetos
authors.forename: Michael A
authors.initials: MA
authors.lastname: Bianchi
authors.forename: Fizza
authors.initials: F
authors.lastname: Jaffery
authors.forename: Sirma
authors.initials: S
authors.lastname: Koutzaki
authors.forename: Mark
authors.initials: M
authors.lastname: Zarella
authors.forename: Robert
authors.initials: R
authors.lastname: Slater
mesh_terms: D001905:Botulinum Toxins / Q000627:therapeutic use; D002012:Bruxism / Q000150:complications; D006801:Humans; D006984:Hypertrophy / Q000150:complications / Q000188:drug therapy / Q000473:pathology*; D008297:Male; D008406:Masseter Muscle / Q000002:abnormalities* / Q000473:pathology; D008875:Middle Aged; D009465:Neuromuscular Agents / Q000627:therapeutic use; D010146:Pain / Q000209:etiology
chemical_list: D009465:Neuromuscular Agents; D001905:Botulinum Toxins
references.citation: Headache. 2009 May;49(5):779-82
references.pmid: 19456887
references.citation: Neurology. 1974 Dec;24(12):1166-70
references.pmid: 4475383
references.citation: Muscle Nerve. 1996 Nov;19(11):1447-56
references.pmid: 8874403
references.citation: Acta Otorhinolaryngol Ital. 2008 Apr;28(2):83-6
references.pmid: 18669073
references.citation: Ear Nose Throat J. 2003 Mar;82(3):198-9
references.pmid: 12696240
references.citation: J Clin Pathol. 2007 Jul;60(7):834-5
references.pmid: 17545559
references.citation: Muscle Nerve. 1993 Dec;16(12):1374-6
references.pmid: 8232395
references.citation: J Craniofac Surg. 2012 May;23(3):e211-4
references.pmid: 22627436
references.citation: Int J Pediatr Otorhinolaryngol. 2000 Jun 9;53(1):57-61
references.pmid: 10862926
references.citation: Neurology. 2003 Feb 25;60(4):724-5
references.pmid: 12601126
references.citation: Br Dent J. 2006 Aug 12;201(3):153-5; quiz 172
references.pmid: 16902544
references.citation: Dentomaxillofac Radiol. 2007 Jul;36(5):296-7
references.pmid: 17586857
references.citation: J Anat. 1999 Apr;194 ( Pt 3):355-62
references.pmid: 10386773
references.citation: Cranio. 2001 Jul;19(3):174-82
references.pmid: 11482829
references.citation: J Neurol Neurosurg Psychiatry. 1976 Aug;39(8):810-6
references.pmid: 956867
references.citation: J Neurosurg Pediatr. 2013 Apr;11(4):451-3
references.pmid: 23394353
references.citation: J Laryngol Otol. 1996 Feb;110(2):161-2
references.pmid: 8729503
references.citation: J Craniofac Surg. 2011 Mar;22(2):736-7
references.pmid: 21415650
references.citation: Scand J Plast Reconstr Surg Hand Surg. 2000 Dec;34(4):391-6
references.pmid: 11195880