Lorenz curves and their use in describing the distribution of 'the total burden' of dental caries in a population.
OBJECTIVE
1) to describe the distribution of the total burden of dental caries in Danish adolescents over a 15-year period using Lorenz curves and, 2) to compare the observed distributions with Poisson distributions.


METHODS
caries data for 15-year-old adolescents reported to the database for the national reporting system for the Danish Municipal Dental Service for Children and Adolescents in 1980 (n = 61,621) and 1995 (n = 50,359).


RESULTS
The DMFS cut-off point for a given percentile had decreased from 1980 to 1995 and Lorenz curves showed a pattern of increasing inequality, even when only diseased individuals (i.e. with DMFS > or = 1) were included. The dispersion was larger than could be expected, if caries developed according to a random pattern modelled by e.g. a Poisson distribution.


CONCLUSIONS
Lorenz curves may be a useful tool in the analysis of caries data, with special reference to determining the appropriateness of implementing high-risk preventive strategies.
Poulsen
S
S
Department of Community Oral Health and Pediatric Dentistry, Royal Dental College, Faculty of Health Sciences, University of Aarhus, Arhus, Denmark. spoulsen@odont.au.dk
Heidmann
J
J
Vaeth
M
M
D000293:Adolescent; D004245:DMF Index; D003718:Denmark / Q000453:epidemiology; D003731:Dental Caries / Q000453:epidemiology*; D006801:Humans; D015233:Models, Statistical; D016012:Poisson Distribution; D011336:Probability; D016008:Statistical Distributions; D018709:Statistics, Nonparametric