title: The Effects of Mandibular Advancement Device on Pressure Pain Threshold of Masticatory Muscles: A Prospective Controlled Cohort Study.
abstract: OBJECTIVE
  To determine if pressure pain thresholds (PPTs) of masticatory and neck muscles change after the application of a mandibular advancement device (MAD) in patients with obstructive sleep apnea (OSA).
  
  
  METHODS
  A prospective study was conducted in a sample of 27 OSA patients (24 males and 3 females; mean age ± standard deviation [SD]: 54.8 ± 11.8, mean apnea-hypopnea index ± SD: 23.5 ± 13.3) and 27 age- and sex-matched healthy controls. Exclusion criteria were signs and symptoms of temporomandibular disorders (TMD), metabolic diseases, and use of antidepressants, analgesics, or anti-inflammatory drugs. A calibrated examiner evaluated PPTs of seven head and neck muscles bilaterally by using a Fischer algometer. In the OSA group, PPTs were recorded immediately before the MAD application (T₀), after 15 days (T₁), and after 6 months (T₂) of therapy; in the control group, PPTs were recorded at the same time intervals. PPT differences at baseline and over time within each group and between OSA and control groups were analyzed by Friedman and Mann-Whitney tests.
  
  
  RESULTS
  There were no PPT differences between groups at baseline. In the OSA group, PPTs of temporalis and masseter muscles decreased significantly at T₁ compared with T₀ (P < .05), but no differences were found at T₂. No significant PPT differences were found in the neck muscles or over time in the control group.
  
  
  CONCLUSIONS
  MAD application induces a decrease of PPTs of masticatory muscles at the beginning of the therapy, but a physiologic adaptation occurs by 6 months.
authors.forename: Giulio
authors.initials: G
authors.lastname: Alessandri-Bonetti
authors.forename: Francesco
authors.initials: F
authors.lastname: Bortolotti
authors.forename: Maria Lavinia
authors.initials: ML
authors.lastname: Bartolucci
authors.forename: Ida
authors.initials: I
authors.lastname: Marini
authors.forename: Vincenzo
authors.initials: V
authors.lastname: D'Antò
authors.forename: Ambra
authors.initials: A
authors.lastname: Michelotti
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D019186:Mandibular Advancement / Q000295:instrumentation*; D008406:Masseter Muscle / Q000502:physiology*; D008875:Middle Aged; D009334:Neck Muscles / Q000502:physiology; D016382:Orthodontic Appliance Design; D017288:Pain Threshold / Q000502:physiology*; D011312:Pressure; D011446:Prospective Studies; D020181:Sleep Apnea, Obstructive / Q000628:therapy; D013703:Temporal Muscle / Q000502:physiology*