COLONIZATION BY MUTANS-STREPTOCOCCI IN THE MOUTHS OF 3-YEAR-OLD AND 4-YEAR-OLD CHINESE CHILDREN WITH OR WITHOUT ENAMEL HYPOPLASIA

This case-control study compared the prevalence and concentration of m utans streptococci (MS) in saliva between children with and without en amel hypoplasia (EHP). A total of 486 3- or 4-year-old Chinese childre n were initially screened for EHP, then distributed into two groups: 2 34 children diagnosed as having EHP were assigned to the case group; 2 52 who were free of EHP were included in the control group. The concen tration of MS in saliva was assayed for each child. Nutritional status was deduced from body height and weight. Birth weight, prematurity, a nd nursing history were also determined. MS were found in 94.7% of the study population. The differences in MS concentrations were not assoc iated with low birth weight, prematurity, length of breast feeding, or body height and weight. A statistically significant association exist ed between the presence of EHP and high counts of MS (p < 0.001). High MS counts were correlated with severity of enamel defects (p < 0.001) . When the caries status of the children was controlled as the confoun ding factor in statistical analyses, the association between EHP and M S decreased but still remained significant (p = 0.025). This study sho ws that high MS counts are correlated with EHP, suggesting that irregu larities in enamel surfaces could be a contributing factor that foster s the increased colonization of MS in the mouths of children.