Examiner reliability of fluorosis scoring: a comparison of photographic and clinical examination findings

Abstract

To assess and compare examiner reliability of clinical and photographic fluorosis examinations using the Fluorosis Risk Index (FRI) among children in the Iowa Fluoride Study (IFS). The IFS examined 538 children for fluorosis and dental caries at age 13 and obtained intraoral photographs from nearly all of them. To assess examiner reliability, duplicate clinical examinations were conducted for 40 of the subjects. In addition, 200 of the photographs were scored independently for fluorosis by two examiners in a standardized manner. Fluorosis data were compared between examiners for the clinical exams and separately for the photographic exams, and a comparison was made between clinical and photographic exams. For all three comparisons, examiner reliability was assessed using kappa statistics at the tooth level. Interexaminer reliability for the duplicate clinical exams on the sample of 40 subjects as measured by kappa was 0.59, while the repeat exams of the 200 photographs yielded a kappa of 0.64. For the comparison of photographic and clinical exams, interexaminer reliability, as measured by weighted kappa, was 0.46. FRI scores obtained using the photographs were higher on average than those obtained from the clinical exams. Fluorosis prevalence was higher for photographs (33 percent) than found for clinical exam (18 percent). Results suggest that interexaminer reliability is greater and fluorosis scores are higher when using photographic compared with clinical examinations.