Clinical appearance of dental fluorosis in permanent teeth in relation to histologic changes

Abstract

Based on studies in Northern Tanzania a new classification system of dental fluorosis is proposed. The classification system includes 10 scores designed to characterize the degree of dental fluorosis affecting buccal/lingual and occlusal surfaces. With aid of polarized and ordinary light microscopy the histologic features behind the individual scores are described. The macroscopic appearance of increasing degrees of dental fluorosis were well correlated to the degree of subsurface porosity. Above a certain level of subsurface hypomineralization various degrees of loss of surface enamel occurred, presumably as a result of posteruptively acquired injuries. Application of the new classification system to samples of children born in areas with 3.5, 6.0 and 21.0 parts/106 F‐ in the water supplies revealed that the distribution of dental fluorosis within the individual followed the same pattern irrespective of fluoride concentration in the water. While the classical Dean index was unable to distinguish between dental fluorosis in the 6.0 and the 21.0 parts/106 area it was possible with the new system to disclose that particularly the posterior teeth were significantly more affected in the latter area. Comparisons of degree of dental fluorosis with available measurements of enamel thickness proved that the within‐tooth as well as within‐dentition variations are determined by enamel thickness rather than length of exposure to body fluids. The limitations of the Dean index are discussed with special attention to its validity as a biological index in relation to current efforts to determine the minimal toxic effect of fluoride on the dental hard tissues.

The effect of non-fluoride factors on risk of dental fluorosis: Evidence from rural populations of the Main Ethiopian Rift

“…DF severity was evaluated based on visual interpretation of individuals' teeth (confirmed by digital images) using the Thylstrup-Fejerskov Index (TFI) which ranges from 0 (no tooth damage and normal translucence) to 9 (complete loss of a tooth) (Thylstrup and Fejerskov, 1978). The TFI was used in this analysis because it displays higher sensitivity than other indices, especially when drinking water concentrations exceed 5 mg/l of F − (Fejerskov, 1988;Rozier, 1994), as was the case for many of the groundwater sources included in this study.…”

“…The TFI was used in this analysis because it displays higher sensitivity than other indices, especially when drinking water concentrations exceed 5 mg/l of F − (Fejerskov, 1988;Rozier, 1994), as was the case for many of the groundwater sources included in this study. During DF progression, teeth initially become chalky and opaque due to subsurface hypomineralization (scores ranging from 1 to 4 indicate increasing degree of opacity), and the teeth then develop pits and grooves due to enamel loss (scores above 5 indicate increasing loss of enamel and pitting) (Thylstrup and Fejerskov, 1978).…”

Non-carious tooth conditions in children in the UK, 2003

“…Hawley et al 9 investigated expressed concern using photographs of teeth with enamel opacities in teenagers in a non-fluoridated community using the Thylstrup and Fejerskov (TF) Index. 10 Subjects were only concerned by a TF score of three or greater.…”

Dental fluorosis in populations from Chiang Mai, Thailand with different fluoride exposures – Paper 1: assessing fluorosis risk, predictors of fluorosis and the potential role of food preparation

“…The images were then integrated into a graphical user interface that randomized and blinded the images which were then displayed on a 32 inch flat screen monitor under controlled lighting. A consensus score for Thylstrup and Fejerskov Index (TF) [1] was then given for each image by two examiners (R.P.E and M.G.M). This was recorded directly by the interface into a Windows (Microsoft Corp., Seattle, Wash., USA) excel file and imported into the Statistical Package for Social Sciences (SPSS 16.0) for statistical analysis.…”

“…However, alongside these benefits it is recognized that the ingestion of fluoride during the period of tooth development increases the risk of developing dental fluorosis, a developmental defect seen as hypomineralization of the enamel [1]. …”