• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.3
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• pp.457-468
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• 2006

It is widely known that individuals with mental retardation (MR) and Down's syndrome (DS) often develop early onset periodontal diseases. In this study, the prevalence of periodontopathic bacteria in MR persons and DS patients was compared with normal persons. Plaque index and gingival index were measured. Five periodontopathic bacteria, Actinobacillus actinomycetemcomitans. Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Fusobacterium nucleatum were surveyed in subgingival plaque samples by the polymerase chain reaction. Results : 1. Plaque index and gingival index were higher in MR persons group and DS patients group than normal persons group (p<0.05). 2. The prevalence of periodontopathic bacteria in normal persons group were lower than that of MR persons group and DS. Significant differences were observed in the prevalence of P. gingivalis, T. denticola and A. actinomycetemcomitans(P<0.05). 3. Prevalence of P. gingivalis(5.9%) at age 8-10 was lower than other ages in normal persons group, and its prevalence increased with age Prevalence of P. gingivalis, T. denticola and A. actinomycetemcomitans at MR persons group and DS patients group were higher than those of same ages of normal persons group. 4. Plaque index was associated with T. denticola and gingival index was associated with T. denticola and A. actinomycetemcomitans(P<0.05). These results suggested that plaque index, gingival index and prevalence of periodontopathic pathogens, especially P. gingivalis, T. denticola and A actinomycetemcomitans in DS patients group and MR persons group are higher than those of normal persons group.