Asgeir Bårdsen

Risk periods associated with the development of dental fluorosis in maxillary permanent central incisors: a meta-analysis

This systematic review of the dental literature (1966-98) concerns risk periods associated with dental fluorosis in the maxillary permanent central incisors. A literature search was organized through the MedLine and the ISI databases. In addition, one unpublished paper (in manuscript) was obtained, as well as one paper published before 1966. However, out of 143 catches, only 10 studies were included in this review. The main reason for exclusions was that the data presented did not meet the criteria given for the present meta-analysis. Among the included papers, 7 pertained to subjects whose exposure to fluoride started at different ages during the enamel formation (Group 1), and 3 were based on subjects who had been exposed from birth and then experienced an abrupt reduction in daily fluoride exposure at different ages during the amelogenesis period (Group 2). The meta-analysis for Group 1 found the odds ratio (OR) for dental fluorosis in children exposed to fluoride early in life (before 2 years of age) to be 7.24 (95% CI; 4.71-11.13) as compared to children exposed later in life (after 2 years of age). The meta-analysis for the studies in Group 2 found the overall OR to be 1.88 (95% CI; 1.35-2.61) for children who had a reduction in fluoride intake after 2 years of age, as compared to individuals who experienced reduction earlier (during the first 2 years). The studies from both groups were pooled and the duration of exposure to fluoride during the first 4 years of life was the independent variable. The meta-analysis now revealed an overall OR of 5.83 (95% CI; 2.83-11.94) for long periods of fluoride exposure (>2 out of the first 4 years) versus shorter periods of exposure (<2 out of the first 4 years of life) during the enamel formation in the maxillary central incisors. Based on the findings of the meta-analysis, no specific period of enamel formation is singled out as being the most critical for the development of dental fluorosis. The duration of fluoride exposure during the amelogenesis, rather than specific risk periods, would seem to explain the development of dental fluorosis in the maxillary permanent central incisor.

Variability in fluoride content of subsurface water reservoirs

Groundwater may contain high concentrations of fluoride. In most countries, however, information on the fluoride content is scarce and anecdotal. The aim of the present study was to make a comprehensive assessment of F- in the groundwater of a representative area of Norway, thereby establishing a more solid basis for appropriate health counseling. Relevant technical information was collected, together with water samples from 1063 underground water sources in 31 municipalities in the county of Hordaland. One thousand and two water samples were analyzed for F- and pH with an F(-)-selective electrode and a pH electrode, respectively. Mean F- was 0.30 mg/l (range, < 0.02-9.48). Fourteen per cent of the wells contained water with F- levels > or = 0.50 mg/l. In three municipalities well water had a mean F- concentration > 0.07 mg/l; in one instance the mean was as high as 1.45 mg/l. In 10 municipalities maximum F- values were > 1.50 mg/l. F- values showed a positive correlation with the pH of the water and the depth of the wells (P < 0.01) and a negative correlation with the age of the well (P < 0.05). The results indicated that low-capacity wells deliver water with a higher F- value than high-capacity wells. This trend, however, was not statistically significant. The results show that high-F groundwater is prevalent and emphasize that information on domestic water supply must be available before supplementary fluoride is prescribed for caries prophylactic purpose.

Dental fluorosis among persons exposed to high- and low-fluoride drinking water in western Norway

The aim of this project was to study the prevalence and severity of dental fluorosis among persons exposed to moderate- to high- or low-fluoride drinking water in western Norway, and to assess the risk factors involved. Subjects aged 5 to 18 years who had been lifelong consumers of moderate- to high-fluoride groundwater (> or = 0.50 mg F/L) were selected for the study (n = 113). A comparison group (n = 105) was chosen among consumers of low-fluoride surface water (approximately 0.10 mg F/L) in the same district. The Thylstrup-Fejerskov (TF) Index was used to score dental fluorosis. A questionnaire was used to obtain information on fluoride exposure and other relevant factors. Among the consumers of low-fluoride water 14.3% showed dental fluorosis (TF score 1-2) as compared to 78.8% in the group consuming moderate- to high-fluoride water (TF scores 1-7). Premolars were most frequently affected, but severe cases (TF scores 3-7) were equally prevalent in maxillary central incisors and first molars. In logistic regression analysis with TF score 0 or TF score > or = 1 as the dependent variable, only fluoride concentration in the drinking water was associated with a statistically increased risk of dental fluorosis (odds ratio: 18.9; 95% CI: 8.85-40.44). In the study area, which was characterised by multiple fluoride sources, uncontrolled groundwater with moderate to high fluoride content was the most important factor in the development of dental fluorosis. In order to prevent dental fluorosis, groundwater wells should routinely be analysed for fluoride.

Prevalence and socio-behavioral influence of early childhood caries, ECC, and feeding habits among 6 – 36 months old children in Uganda and Tanzania

BackgroundEarly childhood caries (ECC) is a serious problem that has remained unexplored in sub-Saharan Africa. This study aimed to identify possible socio-behavioral correlates of ECC focusing 6–36 months old children and their caretakers.MethodsCross sectional studies were conducted in a high fluoride rural area, Manyara, Tanzania and a low fluoride urban area, Kampala, Uganda. Totals of 1221 and 816 child - caretaker pairs attending health care facilities for growth monitoring were recruited in Manyara and Kampala, respectively. All caretakers completed face to face interviews at the health care facility. Children underwent oral clinical examination whereby ECC and Enamel hypoplasia were recorded using the dmft (WHO 1997) and the DDE index (FDI 1992).ResultsThe prevalence of ECC was 3.7% in Manyara and 17.6% in Kampala. According to multiple logistic regression analyses, received oral health information from health worker was the strongest determinant of ECC in Manyara, adjusted OR 0.3, 95% CI 0.09 – 0.93. In Kampala, visible plaque, high sugar intake and presence of enamel hypoplasia associated with ECC, adjusted ORs 2.8 (95% CI 1.61- 4.95), 3.0 (95% CI 1.39 – 6.34) and 2.3 (95% CI 1.36 - 3.95).ConclusionOral health education aimed at caretakers of 6–36 months, including health care workers’ information regarding the detrimental consequences for oral health of frequent sugar consumption and poor oral hygiene is important for prevention of ECC in Tanzania and Uganda.

Traumatic dental injuries - knowledge and awareness among present and prospective teachers in selected urban and rural areas of Norway

AIM to evaluate the knowledge and awareness of traumatic dental injuries (TDI) in children and adolescents among present and prospective teachers in selected parts of Norway. MATERIAL AND METHODS This was a descriptive cross-sectional study among present and prospective teachers. It was based on a questionnaire about TDI in children and adolescents (7-15 years of age). The participants originated from two areas, one rural and one urban. The teacher trainee students were from classes focusing on sport and physical education. Chi-square tests were used for comparisons of groups of responders and relevant variables. RESULTS A total of 143 individuals responded to the questionnaire (response rate 73.7%). Few respondents were aware of the existence of information about managing TDI at their respective schools. Only one responder (rural area) had had any education about TDI, although more than one-third of all the teachers had encountered TDI in school settings. Knowledge related to handling avulsed teeth was lower compared with handling crown fractures. Generally, the teachers had a higher level of knowledge related to the correct handling of TDI compared with the student group and they were also more confident in their respective decisions than the younger group. CONCLUSIONS The findings revealed poor knowledge and awareness of TDI among present and prospective teachers in selected parts of Norway.

Developmental Defects of Enamel in Primary Teeth and Association with Early Life Course Events: A Study of 6--36 Month old Children in Manyara, Tanzania.

BackgroundChildren with low birth weight show an increased prevalence of developmental defects of enamel in the primary dentition that subsequently may predispose to early childhood caries (ECC).Focusing 6–36 months old, the purpose of this study was to assess the frequency of enamel defects in the primary dentition and identify influences of early life course factors; socio-demographics, birth weight, child’s early illness episodes and mothers’ perceived size of the child at birth, whilst controlling for more recent life course events in terms of current breastfeeding and oral hygiene.MethodsA cross-sectional study was conducted in the high fluoride area of Manyara, northern Tanzania including 1221 child-mother pairs who attended Reproductive and Child Health (RCH) clinics for immunization and/or growth monitoring. After the primary caregivers had completed face to face interviews at the health care facility, children underwent oral clinical examination whereby ECC and developmental defects of enamel were recorded using field criteria. All erupted teeth were examined and the enamel defects were assessed on buccal surfaces according to the modified DDE Index.ResultsThe prevalence of enamel defects was 33.3%. Diffuse opacities were the most common defects identified (23.1%), followed by hypoplasia (7.6%) and demarcated opacities (5.0%). The most frequently affected teeth were the upper central incisors (29.0% - 30.5%), whereas lower central incisors (4.3% to 4.5%) were least frequently affected. Multiple logistic regression analysis, adjusting for confounding the factors revealed that having normal birth weight (equal or more than 2500 g) associated with lower odds of having enamel hypoplasia [OR 0.2 (95% CI 0.1-0.7)]. No statistically significant association occurred between birth weight and diffuse opacities, demarcated opacities or combined DDE.ConclusionChildren with the history of low birth weight were more likely than their normal birth weight counterparts to present with enamel hypoplasia. In view of the frequent occurrence of enamel defects and the fact that hypoplasia may constitute a risk factor for future ECC, enamel defects should be included as a dental health indicator in epidemiological studies of children in northern Tanzania.

Traumatic dental injuries in an urban adolescent population in Tirana, Albania

AIM The aim of this study was to gather information about traumatic dental injuries (TDI) in an urban adolescent Albanian population. MATERIAL & METHODS A cross-sectional survey was carried out to acquire epidemiological data about TDI in the permanent incisors of Albanian adolescents. Participants (n = 2789) were adolescents of both genders, aged 16-18 years, attending public high schools in Tirana. RESULTS The occurrence of TDI in the incisors ranged from 8.9% of 16-year-olds to 10.5% of 18-year-olds. A greater proportion of boys (12.4%) had TDI compared with girls (7.7). The most commonly reported causes were collisions (27.5%) followed by physical leisure activities and sports (mainly cycling and swimming/diving) (14.1%) and falls (13.4%). Of the adolescents affected by TDI, 32% had unmet treatment need because of no or inadequate treatment. Adolescents living in districts with low socio-economic level had significantly more TDI with unmet treatment need than those living in districts with high socio-economic level. CONCLUSION The occurrence of TDI among Albanian adolescents was moderate. Adolescents who came from low socio-economic districts had a greater probability of having TDI with unmet treatment need.

Perception of dental fluorosis amongst Ethiopian children and their mothers

This study was conducted in three Ethiopian Rift Valley villages known for endemic fluorosis. Three-hundred-and-six adolescents (12-15 years) and 233 mothers participated. The aim was to study dental fluorosis in the youngsters and to assess the extent of agreement between clinical and self-rated discoloration and pitting of teeth, and also the level at which dental fluorosis is perceived as a problem both by children and their mothers. The children (154 M and 152 F) gave a simple self-assessment of tooth-color and quality of their teeth, and were subsequently examined for dental fluorosis. Finally, four color photographs of teeth with dental fluorosis (TF-scores 2, 3, 5, and 7) were used as references during a structured oral interview of the children, as well as their mothers. At TF score S 2, the prevalence of dental fluorosis on maxillary central incisors was 72% and 37% at TF score S 4. The mean TF score was significantly higher among boys than among girls of unemployed fathers compared to children of employed fathers. The likelihood of reporting problems with dental appearance increased with increasing individual TF scores. The child/mother pairs found teeth with TF scores 2 and 3 esthetically acceptable, while teeth with TF scores 5 and 7 were considered unacceptable. Mothers were more critical of severe fluorosis than were their children.

Risk periods in the development of dental fluorosis

Abstract In order to study the age-related susceptibility to dental fluorosis, 40 children who had been lifelong consumers of moderate- to high-fluoride water (0.55–8.48 mg F/l) were examined, as well as a group of older siblings (n = 40) who were born 6 months to 6 years before the fluoride-containing drinking water was introduced to the household. Background information was obtained through a structured questionnaire. Dental fluorosis was scored according to the TF index. Among the 80 children examined, the permanent incisors were erupted in 66, while 67 had permanent first molars present. As compared to their older siblings, the prevalence of dental fluorosis was significantly higher in the children who had consumed moderate- to high-fluoride water throughout their lives. In a multiple regression analysis, the variable “age when introduced to moderate- to high-fluoride water” came out as the only significant risk factor associated with dental fluorosis. This variable was divided into three categories according to the first exposure to moderate- to high-fluoride drinking water (1) 0–12 months of age, (2) 13–24 months of age and (3) after 24 months of age. Category 3 was used as the reference group. Fluoride exposure starting during the 1st year of life showed the highest odds ratio as compared to exposure only after 2 years of age. The findings indicate that early mineralising teeth (central incisors and first molars) are highly susceptible to dental fluorosis if exposed to fluoride from the first and – to a lesser extent – also from the 2nd year of life.

Dental fluorosis and dental caries in permanent teeth: rural schoolchildren in high-fluoride areas in the Shaanxi province, China.

Objectives. To study the dental fluorosis and caries in the permanent teeth of 12 to 13-year-old children in fluorosis-endemic areas; to assess the relationship between fluorosis and the fluoride content of the drinking water and the relationship between caries and the fluoride content of the water; finally, to analyze the effect of fluoride intake and water stored in clay pots on dental fluorosis. Material and methods. 477 children were divided into 5 groups (A to E) according to the fluoride concentration of the waters, i.e. by 0.4, 1.0, 1.8, 3.5, and 5.6 mg F/l, respectively. Dental fluorosis was assessed by TF score and caries by the DMF-T index. A questionnaire was used to obtain information about water storage and other information relevant to childrens fluoride intake. Results. A positive relationship was found between the mean TF scores and the water fluoride concentration. In groups B and D, the TF score was higher in 13-year-olds than in 12-year-olds. Caries prevalence and mean DMF-T ranged from 2.6% and 0.03 (group E) to 22.1% and 0.38 (group A). Storage of water in clay pots seemed to increase the severity of fluorosis slightly, and to decrease the caries prevalence. Conclusions. Defluoridation of drinking water, or—alternatively—the provision of low-fluoride water sources, should be given high priority in the examined Shaanxi rural areas. Fluoride concentration of drinking water should be maximum 0.6 mg/l. Storage of water in the local clay pots may increase the severity of dental fluorosis.