Comparative study between dental caries prevalence of Down syndrome children and their siblings.

The purpose of this epidemiological study was to determine the differences in the prevalence of caries between individuals with Down syndrome (DS) and their siblings. A sibling-matched, population-based and cross-sectional survey was performed. This study involved 138 (62%) children with DS and 86 (38%) siblings, aged 2-26. The children were compared in different subgroups: [2, 6], [6, 12], and [13, 26]. Data was gathered through the use of a complete questionnaire and clinical observation. Data analysis was performed by using SPSS® v.18.0 software with any p value <.05 considered as significant. The DS group presented a significantly higher percentage of children within the caries-free group: 72% versus 46% of the siblings group (p < .001). In the age gap [2, 6[the median value of DMFT was the same in both groups (p = .918). In the age gap [6, 12] the median value of DMFT in the DS group was 0 and in the siblings group was 1 (p = .004). In the age gap [13, 26] the median value of DMFT in the DS group was 0, whereas in the siblings group the median value was 3, which constitutes a significantly high difference (p = .003). The results of this study suggest that Portuguese children with DS have lower caries prevalence than their siblings.

Voice parameters in children with Down syndrome.

Down syndrome (DS) is the most frequent chromosomal disorder. Commonly, individuals with DS have difficulties with speech and show an unusual quality in the voice. Their phenotypic characteristics include general hypotonia and maxillary hypoplasia with relative macroglossia, and these contribute to particular acoustic alterations. Subjective perceptual and acoustic assessments of the voice (Praat-4.1 software) were performed in 66 children with DS, 36 boys and 30 girls, aged 3 to 8 years. These data were compared with those of an age-matched group of children from the general population. Perceptual evaluations showed significant differences in the group of children with DS. The voice of children with DS presented a lower fundamental frequency (F(0)) with elevated dispersion. The conjunction of frequencies for formants (F(1) and F(2)) revealed a decreased distinction between the vowels, reflecting the loss of articulatory processing. The DS vocalic anatomical functional ratio represents the main distinctive parameter between the two groups studied, and it may be useful in conducting assessments.

Oxidative stress in Portuguese children with Down syndrome.

BACKGROUND: Individuals with Down syndrome have an accelerated process of ageing which is thought to be associated with oxidative stress. AIM: Since Zn/Cu superoxide dismutase is increased by about 50% in children with Down syndrome, glutathione and other less known antioxidant mechanisms were studied to determine whether there were changes in reactive oxygen species. METHODS: Plasma reduced and oxidised glutathione and red blood cells enzymes including acid phosphatase, methemoglobin reductase and transmembrane reductase were evaluated in Portuguese children with Down syndrome and their siblings, who were used as a control group. RESULTS: No significant differences were found between the study and control groups. A negative correlation was noted between total glutathione and acid phosphatase in the siblings without Down syndrome, but not in the children with Down syndrome. CONCLUSION: Although it is claimed that the production of hydrogen peroxide is enhanced in children with Down syndrome, their antioxidant mechanisms do not seem to be significantly different compared with their siblings. This may result in an excess of reactive oxygen species that could help to explain accelerated ageing in children with Down syndrome. Further studies will be needed to shed light on these mechanisms.