Validation of oral status indicators

In planning programmes and developing policy, dental public health officials rely on epidemiological data in the form of composite measures such as the DMFT index. However, the DMFT is often not sufficiently sensitive to detect differences in oral health between population groups. Measures that selectively weight components of the DMFT may be better dental indicators. Sheiham, Maizels and Maizels (1987) suggested a functional measure (FM) that weights filled and sound teeth equally and a tissue health (T-health) measure that differentially weights decayed, filled, and sound teeth. For the present analysis, these indicators were divided by 28 to make their range 0 to 1. The modified indexes are called FMI and THI. Carpay et al. (1988) also suggested a dental health index (DHI) that scores a subset of teeth. Data from 797 participants in the 1980 Iowa Survey of Oral Health that included eight independent variables were used to perform stepwise regression on DMFT, FMI, THI, and DHI to assess how well the independent variables correlated with these four dental indicators. R-square values were 0.37 for FMI and 0.36 for THI, but only 0.19 for DHI and 0.12 for DMFT, suggesting that the FMI and THI were more sensitive as dental health indicators. In addition, calculations made on aggregate data published from three national surveys show that the FMI and THI can detect changes in oral health over time. Because the FMI and THI are as easy to measure and calculate as the DMFT, but appear to be more sensitive, they show promise as indicators of oral health status.