Oral status indicators DMFT and FS-T: reflections on index selection

Oral status in a population has traditionally been described by the DMFT in dex (decayed, filled, and missing teeth). There seems to be contradicting a nd confusing evidence in the literature with regard to the usefulness of di fferent indices. Limitations of the DMFT are recognised, and attempts have been made to develop other indices. Two indices, DMFT and FS-T (filled and sound teeth) have been selected for analysis in the present paper. The purp ose of this paper is to examine the relationship between DMFT and FS-T in d ifferent populations, and to show consequences Of choice of index exemplifi ed in analytical analysis. Data stem from the Trondelag-83 and -94 studies that M ere follow-up studies of the Norwegian portion of the 1973 Internati onal Collaborative Study. Sunflower scatter plots and regression analyses w ere used to describe the Variation in DMFT and FS-T in different population s. DMFT was more suitable fur describing variation in populations with low levels of disease than FS-T, while FS-T was more suitable fur describing va riation in populations with high levels of disease. It may be concluded tha t both DMFT and FS-T should be presented when describing oral status in a p opulation. However, choice of index depends first of all on the purpose of the investigation. If there are theoretical reasons to prefer one index ins tead of the other, the superiority of the alternative index in terms of var iation must be disregarded.