Which of the following index checks the prevalence and severity of dental fluorosis
Community Fluorosis Index (CFI) was Trendly H Dean in 1946. The purpose of this index was to know the prevalence and severity of dental fluorosis in a community. It follows the scoring criteria the same as given for the Modified Dean's fluorosis index. CFI is calculated using the following formula:
CFI = (nXw)/N
where, N = Total population, n = Number of individuals in a community with fluorosis, w = weight for each category.
This gives the public health significance of dental fluorosis. The following weight (w) is given for different categories of Modified Deans dental fluorosis:
Questionable Fluorosis = 0.5 points
Very Mild Fluorosis = 1 point
Mild Fluorosis = 2 points
Moderate Fluorosis = 3 points
Severe Fluorosis = 4 points
After obtaining the weight (w), the values are substituted in the above formula and final scores are obtained. Based on the final scores following interpretations are made for this CFI:
|Range of scores for Community Fluorosis Index||Public health significance|
|0.0 - 0.4||Negative|
|0.4 - 0.6||Borderline|
|0.6 - 1.0||Slight|
|1.0 - 2.0||Medium|
|2.0 - 3.0||Marked|
|3.0 - 4.0||Very marked|
How to calculate CFI:
One hundred children are examined, and 10 children are found to have dental fluorosis. Of these 10 children, 5 have “very mild” fluorosis and 5 have “mild” fluorosis. Since 2 points are assigned for “mild” fluorosis, the total fluorosis points here would be 15 (= 10 points for the 5 mild cases + 5 points for the 5 very mild cases). When divided by the number of children examined, this produces a fluorosis index of 0.15.
Advantage of CFI:
1. It helps to determine the amount of fluoride to added for community fluoridation programs like water fluoridation.
2. It actually helps in assessing the number of people affected by fluorosis in a community i.e. prevalence.
3. it is also useful in knowing the severity of dental fluorosis.
1. It needs good calibration of the examiners
2. There is an overlapping of the scores of interpretation. this may create bias in the estimation of the severity of dental fluorosis.
Other options like Deans fluorosis index, CPITN, and OHI - S index are used for different purposes. Like Deans fluorosis index is used to determine the clinical severity of dental fluorosis but it lacks sensitivity. CPITN index is mainly used to assess the periodontal status of the individual and the community and also helps in determining the treatment needs of the community. OHI - S index is mainly used to know the oral hygiene status using debris and calculus scores.