title: Effects of phototherapy on muscle activity and pain in individuals with temporomandibular disorder: a study protocol for a randomized controlled trial.
abstract: BACKGROUND
  According to the International Association for the Study of Pain (IASP), the term temporomandibular disorder (TMD) regards a subgroup of orofacial pain, the symptoms of which include pain or discomfort in the temporomandibular joint, ears, masticatory muscles and neck on one or both sides, as well as joint sounds, limited mandibular movements or mandibular deviation and difficulties chewing. Phototherapy, such as low-level laser therapy (LLLT) and light-emitting diode (LED) therapy, is one of the resources used to treatment muscle pain. Thus, there is a need to investigate therapeutic resources that combine different wavelengths as well as different light sources (LLLT and LED) in the same apparatus. The aim of the proposed study is to evaluate the effects of four different doses of phototherapy on pain, activity of the masticatory muscles (masseter and bilateral anterior temporal) and joint mobility in individuals with temporomandibular disorder. A further aim is to determine the cumulative effect 24 and 48 hours after a single session.
  
  
  METHODS
  A placebo-controlled, double-blind, randomized, clinical trial will be carried out involving 72 women between 18 and 40 years of age with a diagnosis of myogenous TMD. The participants will then be randomly allocated to four groups totaling 18 individuals per group. Three groups will be submitted to a single session of phototherapy with different light sources, and one group will receive placebo therapy: Group A (2.62 Joules); Group B (5.24 Joules); Group C (7.86 Joules); and Group D (0 Joules). The following assessment tools will be administered on four separate occasions (baseline and immediately after, 24 h after and 48 h after phototherapy). Pain intensity will be assessed using the visual analog scale for pain, while pain thresholds will be determined using algometer, and electromyographic (EMG) analysis on the masseter and anterior temporal muscles.
  
  
  CONCLUSIONS
  The study will contribute to the practice of the evidence-based use of phototherapy in individuals with a myogenous TMD. Data will be published after the study is completed.
  
  
  BACKGROUND
  This study is registered with the Brazilian Registry of Clinical Trials, NCT02018770, date of registration: 7 December 2013.
authors.affiliation: Student, Postgraduate Program in Rehabilitation Sciences, Center for Support to Research on Movement Analysis, University Nove de Julho (UNINOVE), Rua Profa Maria Jose Barone Fernandes, 300, São Paulo, SP 02117-020, Brazil. carolinaherpich12@hotmail.com.
authors.forename: Carolina Marciela
authors.initials: CM
authors.lastname: Herpich
authors.forename: Ernesto Cesar Pinto
authors.initials: EC
authors.lastname: Leal-Junior
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: Amaral
authors.forename: Juliana de Paiva
authors.initials: Jde P
authors.lastname: Tosato
authors.forename: Igor Phillip dos Santos
authors.initials: IP
authors.lastname: Glória
authors.forename: Marília Barbosa Santos
authors.initials: MB
authors.lastname: Garcia
authors.forename: Bruno Roberto Borges
authors.initials: BR
authors.lastname: Barbosa
authors.forename: Yasmin
authors.initials: Y
authors.lastname: El Hage
authors.forename: Éric Edmur Camargo
authors.initials: ÉE
authors.lastname: Arruda
authors.forename: Cid Ándre Fidelis de Paula
authors.initials: CÁ
authors.lastname: Gomes
authors.forename: Monique Sampaio
authors.initials: MS
authors.lastname: Rodrigues
authors.forename: Dowglas Fernando Magalhães
authors.initials: DF
authors.lastname: de Sousa
authors.forename: Paulo de Tarso Camillo
authors.initials: Pde T
authors.lastname: de Carvalho
authors.forename: Sandra Kalil
authors.initials: SK
authors.lastname: Bussadori
authors.forename: Tabajara de Oliveira
authors.initials: Tde O
authors.lastname: Gonzalez
authors.forename: Fabiano
authors.initials: F
authors.lastname: Politti
authors.forename: Daniela Aparecida
authors.initials: DA
authors.lastname: Biasotto-Gonzalez
mesh_terms: D000293:Adolescent; D000328:Adult; D001696:Biomechanical Phenomena; D001938:Brazil; D002985:Clinical Protocols; D004311:Double-Blind Method; D004576:Electromyography; D005157:Facial Pain / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D005260:Female; D006801:Humans; D028022:Low-Level Light Therapy / Q000379:methods*; D008406:Masseter Muscle / Q000503:physiopathology*; D010147:Pain Measurement; D017288:Pain Threshold; D016059:Range of Motion, Articular; D012107:Research Design; D013703:Temporal Muscle / Q000503:physiopathology*; D013704:Temporomandibular Joint / Q000503:physiopathology*; D013705:Temporomandibular Joint Disorders / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult