Caries Severity in Nevada Youth using Mean DMFT Scores and Significant Caries Index (SiC)

Introduction: Researchers have found a skewed distribution in caries prevalence that common indices such as MeanDMFT (decayed, missing and filled teeth) may not accurately reflect. The purpose of this study was to evaluate the severity of caries in a cohort of Nevada youth comparing MeanDMFT with Significant Caries Index (SiC) proposed by the World Health Assembly (WHA) in 2000.

Methods: A state-wide surveillance program has been conducting oral health screenings since 2001. Trained and calibrated licensed dental examiners document oral health indices of middle/high school students using 2 mobile dental clinics in Nevada. The 2006/2007 academic year database was used to compute MeanDMFT scores(N=7326). SiC Indices were computed by sorting students according to DMFT scores, selecting the top 1/3 highest values(n=2442), and then calculating MeanDMFT for this subgroup. Descriptive statistics and t-tests were computed to determine differences between gender, ethnicity.

Results: Results show a significantly higher SiC Index (M=6.44;SD=2.63) vs. MeanDMFT (M=2.70;SD3.17)(p=0.0001). Significant differences were found in gender in MeanDMFT (Girls=2.87,SD=3.27;Boys=2.53,SD2.53) but not in Sic Indices (Girls=6.52,SD2.57;Boys=6.33,SD2.57). Significant differences in MeanDMFT were found when comparing ethnicity, Hispanics having higher MeanDMFT scores (M=3.17,SD=3.26) than non-Hispanics (M=2.49,SD3.15). When looking at Sic Indices, no significant differences were found between Hispanics (M=6.36,SD=2.56) vs. non-Hispanics (M=6.49,SD2.69).

Conclusion: Results indicate a skewed distribution regarding caries severity in this cohort. While the MeanDMFT indicates caries levels below the WHA goal of 3.0, the SiC index identifies a large subgroup with higher caries rates. This analysis suggests using both indices to expand understanding of caries severity within populations.