A visual analog scale for measuring dental fluorosis severity

Abstract

To date, no continuous scale exists for measuring the severity of dental fluorosis (DF). The authors developed and validated a visual analog scale (VAS) for DF. They tested the scale in clinical (DF-endemic area) and laboratory settings. Dentists and nondentists (23 per group) were asked to grade the DF severity in photographs of 23 anterior teeth with different DF levels (using a 100-millimeter VAS) to create a VAS for DF. Statistical analysis was performed to validate the new scale. The authors used clinical and laboratory (unerupted third molars) analyses to assess the usefulness of the VAS. The authors used an intraclass correlation coefficient (ICC) to assess the interexaminer (ICC = .79: good agreement) and intraexaminer (.88 < ICC < .97: excellent agreement) reliability during creation of the scale. They used the Spearman rank correlation (r(s)) to validate the VAS against the gold standards (that is, the Thylstrup-Fejerskov index [TFI] and Dean's index [DI]) (the results showed excellent or good correlation for 45 examiners). Two dentist examiners clinically tested the new VAS, and the results showed excellent (r(s) = .922, P < .001) correlation and excellent ICC between the examiners (ICC = .96), as well as good ICC between the TFI and the VAS for DF (ICC = .6). The laboratory study showed better correlation between fluoride concentration and the VAS for DF than between fluoride concentration and the TFI. Because of its simplicity, precision and utility in statistical applications, the VAS for DF can be useful in DF studies.