title: The effect of cervical spine manual therapy on normal mouth opening in asymptomatic subjects.
abstract: OBJECTIVE
  Temporomandibular disorders are a group of disorders affecting the temporomandibular joint and/or masticatory muscles. One of the signs associated with temporomandibular disorders is a reduction in mouth opening. During normal mouth opening, extension occurs at the cervical-cranial junction. The purpose of this investigation was to determine if manual therapy applied to the cervical-cranial junction would significantly improve mouth-opening capacity.
  
  
  METHODS
  One hundred one participants were randomly assigned to either an Active Release Technique (ART) group; high-velocity, low-amplitude manipulation (HVLA) group; or control group. A blinded investigator measured mouth opening using a TheraBite range of motion scale (TheraBite Corporation, West Chester, PA). Participants received ART to the suboccipitals or HVLA to the cervical spine at C1 or sat with an investigator for 3 minutes with no treatment. After the treatment session, mouth opening was remeasured. A repeated-measures analysis of variance was used to compare the group mean values. The a priori alpha level was .05.
  
  
  RESULTS
  The repeated-measures analysis of variance showed no significant difference between the ART, HVLA, and control groups' pretreatment and posttreatment measurements (F = 0.41, P > .05).
  
  
  CONCLUSIONS
  Manual therapy to the cervical spine did not significantly improve mouth opening in this asymptomatic population. Future trials using participants with restricted mouth-opening measures are warranted.
authors.affiliation: Research Resident, Division of Research, Logan College of Chiropractic, St Louis, MO 63006.
authors.forename: James W
authors.initials: JW
authors.lastname: George
authors.forename: Jason
authors.initials: J
authors.lastname: Fennema
authors.forename: Adam
authors.initials: A
authors.lastname: Maddox
authors.forename: Martha
authors.initials: M
authors.lastname: Nessler
authors.forename: Clayton D
authors.initials: CD
authors.lastname: Skaggs
references.citation: J Dent Res. 2002 Nov;81(11):747-51
references.pmid: 12407088
references.citation: Rev Stomatol Chir Maxillofac. 2005 Nov;106(5):267-71
references.pmid: 16292219
references.citation: Head Face Med. 2006 Aug 16;2:25
references.pmid: 16914032
references.citation: J Oral Rehabil. 2004 Feb;31(2):110-6
references.pmid: 15009593
references.citation: Phys Ther. 2006 May;86(5):710-25
references.pmid: 16649894
references.citation: J Dent Res. 2000 Jun;79(6):1378-84
references.pmid: 10890716
references.citation: J Oral Rehabil. 1999 May;26(5):428-35
references.pmid: 10373091
references.citation: J Orofac Pain. 2006 Winter;20(1):9-23
references.pmid: 16483016
references.citation: J Orthop Sports Phys Ther. 2000 Aug;30(8):484-92
references.pmid: 10949505
references.citation: Photomed Laser Surg. 2006 Feb;24(1):45-9
references.pmid: 16503788
references.citation: Tex Dent J. 2000 Jul;117(7):30-9
references.pmid: 11858062
references.citation: Clin Oral Investig. 1998 Jun;2(2):54-7
references.pmid: 15490776
references.citation: Br J Oral Maxillofac Surg. 1997 Feb;35(1):40-2
references.pmid: 9043002
references.citation: Cranio. 1987 Apr;5(2):130-8
references.pmid: 3471354