Oral diseases such as caries and periodontal disease (infections of the gums and of the tooth support tissues) are among the most widespread diseases in the world. They affect all populations to varying degrees.
Dental caries in the world: a situation of contrast
The index for measuring the extent to which a population is affected by caries is the mean DMFT, which in a group of individuals counts the average number of teeth that are Decayed, Missing (on account of caries) and Filled. It is a simple, rapid and universally applicable measurement that has been widely used for several decades.
We have drawn up a scale for severity of involvement at various key ages: 12, 35-44, 65 and over.
At age 12 the 5 level scale varies from 0.0 to 6.6 or more: a DMFT between 0.0 and 1.1 is considered very low, a figure of 6. 6 or more is very high, while a moderate DMFT is between 2.7 and 4.4 decayed.
Any country undertaking an analysis of its oral health situation can compare the results with WHO' s worldwide objective: by the year 2017 no more than three decayed, missing and filled teeth at age 12. By repeating the analysis at regular intervals (WHO recommends an evaluation every five years) it is possible to monitor the trend in caries prevalence, to estimate the needs for care and prevention and to adjust personnel training and services accordingly. It should be pointed out that the simplified oral health survey method developed by WHO is reliable, very inexpensive, can be used anywhere and provides comparable data both in the richest countries and in the poorest.
WHO' s Oral Health Unit provides technical support for epidemiological surveys and processes country data free of charge on request.
The information collected is stored in the Global Oral Data Bank (GODB) system in the catalogue of United Nations data banks, whereby it is possible to follow the worldwide trend. Every year since 1969, WHO has compiled a world map of caries at age 12. In 1969 the overall picture showed sharp contrasts: the DMFT was very high, high or at least moderate (between 2.7 and 4.4) in the industrialized countries, whereas it was generally very low, low and occasionally moderate in the developing countries.
Over the next two decades there was a downward movement and sometimes a spectacular fall in the prevalence of caries in virtually all the industrialized countries.
In the developing countries the general trend is for caries prevalence to increase except where prevention programmes have been set up.
Every year since 1980 the WHO Oral Health Unit has calculated the mean global DMFT at age 12, weighted for population. The resulting graphs display the trends in dental caries in the industrialized countries, in the developing countries and for mankind as a whole.
The trend in the mean since 1980 justifies measured optimism for the next 10 years, although the situation is still delicate in as much as a small increase in very highly populated countries is all that is needed to take the mean above 3.
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What is the explanation for the spectacular drop in caries prevalence in some countries? How can it be prevented from rising again? How c，英语论文，英语论文 |
