title: Type and extent of enamel defects in juvenile idiopathic arthritis (JIA).
abstract: OBJECTIVE
  To establish whether there is an increased prevalence and extent of enamel defects associated with Juvenile Idiopathic Arthritis (JIA) in patients in the North of England.
  
  
  METHODS
  clinical examination of subjects and age and sex matched controls.
  
  
  METHODS
  The labial surfaces of all erupted permanent teeth in subjects, as well as age and sex matched controls, were examined. They were classified for type and extent of defects according to the Modified DDE index. The records of 146 subjects and 142 controls were available for analysis.
  
  
  METHODS
  defects were expressed as the percentage of subjects or controls with or without any defects or specific types of defect. Fisher's exact test was used to compare the prevalence of disease in the two groups with significance being accepted at the 5% level. In addition, 95% confidence intervals for the relative risk of disease in the two groups were derived.
  
  
  RESULTS
  There was no significant difference between subjects and controls for the presence of any type of defect (p=0.48), demarcated opacities (p=0.39), diffuse opacities (p=0.71), or hypoplasias (p=0.19). There was no significant increase in severity of defects in subjects compared with controls. There was also no significant difference when comparing the group diagnosed before the age of 4 (0-3) and the group diagnosed after the age of 4 (>4) years.
  
  
  CONCLUSIONS
  There was no greater overall prevalence of enamel defects or specific type of defects and no greater extent of them in subjects with JIA compared with age and sex matched controls.
authors.affiliation: Glasgow Dental Hospital and School, University of Glasgow and North Glasgow NHS Trust, Glasgow, UK.
authors.forename: R R
authors.initials: RR
authors.lastname: Welbury
authors.forename: J M
authors.initials: JM
authors.lastname: Thomason
authors.forename: J L
authors.initials: JL
authors.lastname: Fitzgerald
authors.forename: I N
authors.initials: IN
authors.lastname: Steen
authors.forename: H E
authors.initials: HE
authors.lastname: Foster