title: Analgesic and sedative effects of melatonin in temporomandibular disorders: a double-blind, randomized, parallel-group, placebo-controlled study.
abstract: BACKGROUND
  The association between myofascial temporomandibular disorder (TMD) and nonrestorative sleep supports the investigation of therapies that can modulate the sleep/wake cycle. In this context, melatonin becomes an attractive treatment option for myofascial TMD pain.
  
  
  OBJECTIVE
  To investigate the effects of melatonin on pain (primary aim) and sleep (secondary aim) as compared with placebo in a double-blind, randomized, parallel-group trial.
  
  
  METHODS
  Thirty-two females, aged 20-40 years, with myofascial TMD pain were randomized into placebo or melatonin (5mg) treatment groups for a period of four weeks.
  
  
  RESULTS
  There was a significant interaction (time vs. group) for the main outcomes of pain scores as indexed by the visual analogue scale and pressure pain threshold (analysis of variance; P<0.05 for these analyses). Post hoc analysis showed that the treatment reduced pain scores by -44% (95% CI -57%, -26%) compared with placebo, and it also increased the pressure pain threshold by 39% (95% CI 14%, 54%). The use of analgesic doses significantly decreased with time (P<0.01). The daily analgesic doses decreased by -66% (95% CI -94%, -41%) when comparing the two groups. Additionally, melatonin improved sleep quality, but its effect on pain was independent of the effect on sleep quality.
  
  
  CONCLUSIONS
  This study provides additional evidence supporting the analgesic effects of melatonin on pain scores and analgesic consumption in patients with mild-to-moderate chronic myofascial TMD pain. Furthermore, melatonin improves sleep quality but its effect on pain appears to be independent of changes in sleep quality.
authors.affiliation: Postgraduate Program in Medical Sciences, Faculty of Medicine, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Liliane Pinto
authors.initials: LP
authors.lastname: Vidor
authors.forename: Iraci L S
authors.initials: IL
authors.lastname: Torres
authors.forename: Izabel Cristina
authors.initials: IC
authors.lastname: Custódio de Souza
authors.forename: Felipe
authors.initials: F
authors.lastname: Fregni
authors.forename: Wolnei
authors.initials: W
authors.lastname: Caumo
mesh_terms: D000328:Adult; D018712:Analgesics, Non-Narcotic / Q000008:administration & dosage; D002492:Central Nervous System Depressants / Q000008:administration & dosage; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D006993:Hypnotics and Sedatives / Q000008:administration & dosage; D008550:Melatonin / Q000008:administration & dosage*; D010146:Pain / Q000175:diagnosis* / Q000517:prevention & control*; D010147:Pain Measurement / Q000187:drug effects*; D015990:Placebo Effect; D007319:Sleep Initiation and Maintenance Disorders / Q000175:diagnosis / Q000517:prevention & control*; D013706:Temporomandibular Joint Dysfunction Syndrome / Q000175:diagnosis* / Q000517:prevention & control*; D016896:Treatment Outcome
chemical_list: D018712:Analgesics, Non-Narcotic; D002492:Central Nervous System Depressants; D006993:Hypnotics and Sedatives; D008550:Melatonin