title: The relationship between temporomandibular dysfunction and head and cervical posture.
abstract: OBJECTIVE
  This study aimed to evaluate the possibility of any correlation between disc displacement and parameters used for evaluation of skull positioning in relation to the cervical spine: craniocervical angle, suboccipital space between C0-C1, cervical curvature and position of the hyoid bone in individuals with and without symptoms of temporomandibular dysfunction.
  
  
  METHODS
  The patients were evaluated following the guidelines set forth by RDC/TMD. Evaluation was performed by magnetic resonance imaging for establishment of disc positioning in the temporomandibular joints (TMJs) of 30 volunteer patients without temporomandibular dysfunction symptoms and 30 patients with symptoms. Evaluation of skull positioning in relation to the cervical spine was performed on lateral cephalograms achieved with the individual in natural head position. Data were submitted to statistical analysis by Fisher's exact test at 5% significance level. To measure the degree of reproducibility/agreements between surveys, the kappa (K) statistics was used.
  
  
  RESULTS
  Significant differences were observed between C0-C1 measurement for both symptomatic (p=0.04) and asymptomatic (p=0.02). No statistical differences were observed regarding craniocervical angle, C1-C2 and hyoid bone position in relation to the TMJs with and without disc displacement. Although statistically significant difference was found in the C0-C1 space, no association between these and internal temporomandibular joint disorder can be considered.
  
  
  CONCLUSIONS
  Based on the results observed in this study, no direct relationship could be determined between the presence of disc displacement and the variables assessed.
authors.affiliation: Dental School of Piracicaba, State University of Campinas, Piracicaba, SP, Brazil.
authors.forename: Ricardo Alves
authors.initials: RA
authors.lastname: Matheus
authors.forename: Flávia Maria de Moraes
authors.initials: FM
authors.lastname: Ramos-Perez
authors.forename: Alynne Vieira
authors.initials: AV
authors.lastname: Menezes
authors.forename: Gláucia Maria Bovi
authors.initials: GM
authors.lastname: Ambrosano
authors.forename: Francisco
authors.initials: F
authors.lastname: Haiter-Neto
authors.forename: Frab Norberto
authors.initials: FN
authors.lastname: Bóscolo
authors.forename: Solange Maria
authors.initials: SM
authors.lastname: de Almeida
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D002508:Cephalometry; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005157:Facial Pain / Q000503:physiopathology; D005260:Female; D006257:Head / Q000503:physiopathology*; D006801:Humans; D006928:Hyoid Bone / Q000000981:diagnostic imaging / Q000503:physiopathology; D004204:Joint Dislocations / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008406:Masseter Muscle / Q000503:physiopathology; D010147:Pain Measurement; D010173:Palpation; D011187:Posture; D011859:Radiography; D019224:Temporomandibular Joint Disc / Q000473:pathology; D013705:Temporomandibular Joint Disorders / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*