Oral health disparities among adolescents from urban and rural communities of central Chile

Purpose: Rural populations may have increased risk for prevalent oral diseases. The aim of this study was to compare oral health status of adolescents of rural and urban areas from central Chile.
Subjects and Methods: A representative sample of 552 and 486 adolescents of 12 and 15 years of age, respectively, was examined using WHO methods. Adolescents were chosen from schools belonging to urban and rural districts of the region. Caries status was obtained by DMFT (decayed, missing, filled teeth) and SiC (Significant Caries) indexes. The gingival exam included the Oral Hygiene Index (OHI) of Silness and Löe and the Gingival Index (GI) of Löe and Silness. Clinical Attachment Loss and Community Periodontal Index (CPI), were restricted to 15 year-old adolescents. Statistical comparisons of medians and means were performed with the Mann-Whitney U Test. To determine the association between caries experience and oral hygiene and gingival indexes, Spearman's correlation was used at p<0.05.
Results: Twelve year-old children from rural areas had caries prevalence of 67.5%, which was significantly higher (p<0.05) than children from urban areas who had 54.04%. Caries experience of 12-year-old rural children was significantly higher (DMFT: 3.36; SD 2.71) than that of urban children (DMFT: 2.29; SD 2.17) (p=0.0001). Rural adolescents showed also increased caries severity with a SiC value of 6.21; SD 2.44, whereas urban children showed 4.71; SD 1.74 (p=0.0001). For periodontal indexes, the average GI for 12-year olds was 1.51; SD 0.33, that corresponds to moderate inflammation, but rural subjects (1.55; SD 0.34) had higher values (p=0.002) than their urban counterparts (1.45; SD 0.29). In 15-year old adolescents, caries prevalence was significantly higher in rural (73.58%) than in urban individuals (64.59%) (p<0.05). Like in the other age group, caries experience for rural was higher than urban
15-year-olds, with DMFT 5.03; SD 3.61 and 4.65; SD 3.58, respectively (p=0.238). The SiC in the rural subjects (9.16; SD 2.26) of this age group was significantly higher than urban adolescents (8.51; SD 3.00). No significant differences either in the OHI (p=0.418) or in the GI (p=0.624) were observed
between rural and urban participants.
Conclusion: Adolescents of central Chile show clear disparities in oral health, with rural communities more affected. Gingival health seems to be less impacted by rurality than caries experience. Other social determinants of oral health may also explain these results and further research appears necessary.