title: Suture restriction of the temporal bone as a risk factor for acute otitis media in children: cohort study.
abstract: BACKGROUND
  Eustachian tube (ET) dysfunction plays an important role in the pathogenesis of acute otitis media (AOM). Unfortunately, there is a lack of knowledge about the exact role of the ET's bony support, the temporal bone, on occurrence of AOM. This study investigates whether severe suture restriction of the temporal bone is a risk factor for development of AOM in young children.
  
  
  METHODS
  Using a prospective cohort design, 64 children aged 6 to 18 months without prior history of AOM were followed during the cold season (September 2009 to April 2010). Temporal bone status (categorized as with or without severe suture restriction) was evaluated using palpation and a cranial bone mobility test. Information about potential baseline confounders and risk factors for AOM (gender, age, birth weight, gestational age, use of pacifier, daycare attendance, presence of siblings, low socioeconomic status, breastfeeding ≥ 6 months, parental smoking and history of upper respiratory tract infection) were also collected. Occurrence of AOM diagnosed by physicians blinded to temporal bone status was the main outcome. Data were analyzed using hierarchical linear and nonlinear (multilevel) models.
  
  
  RESULTS
  Severe suture restriction of the temporal bone was identified in 23 children (35.9%). At least one AOM episode was diagnosed in 14 (48.3%) of the ears associated with temporal bones previously identified as having severe suture restriction and in 28 (28.3%) of those without severe suture restriction. Higher risk for AOM was explained by severe suture restriction of the temporal bone (adjusted relative risk (RR), 2.26, 95% CI 1.43 to 2.91, p<.01), pacifier use (RR, 2.59, 95% CI 1.51 to 3.22, p<.01) and younger age (RR, 0.22, 95% CI 0.10 to 0.52, p=.001).
  
  
  CONCLUSIONS
  The study results indicate that severe suture restriction of the temporal bone is a risk factor for AOM in young children. Subsequent intervention studies are needed to determine if this mechanical risk factor can be modified in young children.
authors.affiliation: School of Rehabilitation, Faculty of Medicine and Health Sciences, University of Sherbrooke, 3001 12e Avenue nord, Sherbrooke, QC J1H 5N4, Canada. Chantal.Morin@USherbrooke.ca
authors.forename: Chantal
authors.initials: C
authors.lastname: Morin
authors.forename: Dominique
authors.initials: D
authors.lastname: Dorion
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Moutquin
authors.forename: Mélanie
authors.initials: M
authors.lastname: Levasseur
mesh_terms: D000208:Acute Disease; D015331:Cohort Studies; D003393:Cranial Sutures / Q000473:pathology*; D005260:Female; D006801:Humans; D007223:Infant; D016014:Linear Models; D008297:Male; D016017:Odds Ratio; D010033:Otitis Media / Q000209:etiology*; D011446:Prospective Studies; D012307:Risk Factors; D016037:Single-Blind Method; D013701:Temporal Bone / Q000473:pathology*