Assessment of the validity and consequences of different methods of expressing the severity of dental fluorosis in a subject

Prevalence of oral diseases/conditions in Uganda

OBJECTIVES

The aim was to report the prevalence of oral diseases/conditions among a Ugandan population.

METHODS

Subjects aged 12 (n=696) and 35-44 years (n=396) were chosen from randomly selected urban and peri-urban areas of Arua, Mbale, Kampala and Mbarara districts. They were clinically examined by 4 trained and calibrated dentists for oral diseases/conditions using criteria described by World Health Organisation.

RESULTS

Dental caries (DMFT >or=1) was recorded in 40% and 62.5% of the children and adults, respectively. The overall mean DMFT score was 0.9 for children and 3.4 for adults. Caries was significantly more severe in females as compared to males in children (p<0.05), whereas in adults, there was no significant gender difference. Kampala had a significantly higher mean DMFT score compared to other districts in all age groups (p>0.05). Culculus deposits were generally, more prevalent in adults as compare to children except in Mbarara district. Gum bleeding was also significantly more prevalent among children as compared to adults (p<0.05). Significantly higher prevalence of gum bleeding in both children and adults was recorded in Arua district as compared to other areas (p<0.05). Each of the age groups had a prevalence of malocclusion of 61%. However, the severity of malocclusion varied between age groups and districts. The prevalence of dental fluorosis was 3% and 4% for children and adults, respectively. All subjects in Arua district were fluorosis-free. Tetracycline enamel staining was less than 1% in both age groups. Enamel attrition was more prevalent in adults as compared to children: 19% versus 1%.

CONCLUSION

The prevalence of oral diseases/conditions was generally low among the study population. Caries experience was significantly higher in the Kampala (urban) district as compared to rural districts in all age groups; the D - component being the major contributor.

Severity of dental caries among 12-year-old Sudanese children with different fluoride exposure

The aim of this study was to assess the effect of fluoride on the severity of caries among children exposed to different concentrations of fluoride in the drinking water and living in rural areas in the Sudan. Permanently resident schoolchildren (n = 299) aged 11-13 years from three villages were clinically examined under field conditions. The caries criterion was teeth in need of extraction or extracted; only molars were recorded. Dental fluorosis was scored on all buccal tooth surfaces by the Thylstrup and Fejerskov index. The fluoride concentrations of the drinking water were assessed in samples (n = 25) collected from wells and households. Predictors of caries were assessed by logistic regression analyses. There was no significant difference regarding age and gender distribution between the areas (P > 0.05, df = 2, Kruskal-Wallis test). The socio-economic conditions in these villages were presumed to be equal. Significantly different fluoride concentrations in the drinking water were verified by the severity of dental fluorosis. Children in Abu Delaig, drinking water with 1.0-2.0 mg fluoride/L (median = 1.8), had significantly higher caries prevalence (21% versus 8%) than in a 0.4 mg fluoride area. Area was the only significant predictor for caries; odds ratio 3.7 for children in Abu Delaig compared with the low fluoride area. There was no difference in caries prevalence between the lowest and the highest fluoride (2.9 mg) area. This study failed to demonstrate an effect of fluoride in drinking water on caries experience when the end point was molars indicated for extraction or missing because of caries.