1984), which combines Deans index and the TF index; and the fluorosis risk index (Pendrys 1990), which is intended to define the time at which fluoride exposure occurs, and relates fluorosis risk with tooth development stage. Deans index
Deans fluorosis index was first published in 1934 by H. Trendley Dean. The index underwent two changes, appearing in its final form in 1942. An individuals fluorosis score is based on the most severe form of fluorosis found on two or more teeth. TF index
Proposed by Thylstrup and Fejerskov in 1978, the TF index represents a logical extension of Deans index, incorporating modern understanding of the underlying pathology of fluorosis. It scores the spectrum of fluorotic changes in enamel from 0 to 9, allowing more precise definition of mild and severe cases. Causes
Dental fluorosis is caused by a higher than normal amount of fluoride ingestion whilst teeth are forming. Primary dentine fluorosis and enamel fluorosis can only happen during tooth formation, so fluoride exposure occurs in childhood. Enamel fluorosis has a white opaque appearance which is due to the surface of the enamel being hypomineralised.The most superficial concern in dental fluorosis is aesthetic changes in the permanent dentition (the adult teeth). The period when these teeth are at highest risk of developing fluorosis is between when the child is born up to 6 years old, though there has been some research which proposes that the most crucial course is during the first 2 years of the childs life.
From roughly 7 years old thereafter, most childrens permanent teeth would have undergone complete development (except their wisdom teeth), and therefore their susceptibility to fluorosis is greatly reduced, or even insignificant, despite the amount of intake of fluoride. The severity of dental fluorosis depends on the amount of fluoride exposure, the age of the child, individual response, weight, degree of physical activity, nutrition, and bone growth. Individual susceptibility to fluorosis is also influenced by genetic factors.Many well-known sources of fluoride may contribute to overexposure including dentifrice/fluoridated mouthrinse (which young children may swallow), excessive ingestion of fluoride toothpaste, bottled waters which are not tested for their fluoride content, inappropriate use of fluoride supplements, ingestion of foods especially imported from other countries, and public water fluoridation. The last of these sources is directly or indirectly responsible for 40% of all fluorosis, but the resulting effect due to water fluoridation is largely and typically aesthetic. Severe cases can be caused by exposure to water that is naturally fluoridated to levels above the recommended levels, or by exposure to other fluoride sources such as brick tea or pollution from high fluoride coal.Dental fluorosis has been growing in the United States concurrent with fluoridation of municipal water supplies, although disproportionately by race. A 2010 CDC report acknowledges an overall incidence of dental fluorosis of 22% from 1986-87 increased to 41% in the early 21st century, with an increase in moderate to severe dental fluorosis from 1% to 4%.