Balancing the role of the dental school in teaching, research and patient care; including care for underserved areas.

Inequalities within dentistry are common and are reflected in wide differences in the levels of oral health and the standard of care available both within and between countries and communities. Furthermore there are patients, particularly those with special treatment needs, who do not have the same access to dental services as the general public. The dental school should aim to recruit students from varied backgrounds into all areas covered by the oral healthcare team and to train students to treat the full spectrum of patients including those with special needs. It is essential, however, that the dental student achieves a high standard of clinical competence and this cannot be gained by treating only those patients with low expectations for care. Balancing these aspects of clinical education is difficult. Research is an important stimulus to better teaching and better clinical care. It is recognized that dental school staff should be active in research, teaching, clinical work and frequently administration. Maintaining a balance between the commitments to clinical care, teaching and research while also taking account of underserved areas in each of these categories is a difficult challenge but one that has to be met to a high degree in a successful, modern dental school.

Severe dental fluorosis in a Tanzanian population consuming water with negligible fluoride concentration.

OBJECTIVES: To identify risk factors for dental fluorosis that cannot be explained by drinking water fluoride concentration alone. METHODS: Two hundred eighty-four Tanzanian children ages 9 to 19 (mean 14.0+/-SD 1.69), who were lifetime residents at differing altitudes (Chanika, 100 m; Rundugai, 840 m; and Kibosho, 1,463 m; Sites 1, 2, and 3 respectively) were examined for dental fluorosis and caries. They were interviewed about their food habits, environmental characteristics and use of a fluoride-containing food tenderizer known locally as magadi. Meal, urine, water and magadi samples supplied by the participants were analyzed for fluoride content. Urine samples were also analyzed for creatinine concentration. Four magadi samples from Sites 1 and 3 were analyzed for complete element composition. RESULTS: Of the 13 water samples from Site 2, 10 contained > or =4 mg/L F, ranging from 1.26 to 12.36 mg/L with a mean+/-SD of 5.72+/-4.71 mg/L. Sites 1 and 3 had negligible water fluoride of 0.05+/-0.05 and 0.18+/-0.32 mg/L respectively. Mean TFI fluorosis scores (range 0-9) for Site 2 were high: 4.44+/-1.68. In Sites 1 and 3, which both had negligible water fluoride, fluorosis scores varied dramatically: Site 1 mean maximum TFI was 0.01+/-0.07 and Site 3 TFI was 4.39+/-1.52. Mean DMFS was 1.39+/-2.45, 0.15+/-0.73 and 0.19+/-0.61 at Sites 1, 2, and 3, respectively. There were no restorations present. Urinary fluoride values were 0.52+/-0.70, 4.34+/-7.62, and 1.43+/-1.80 mg/L F at Sites 1, 2, and 3, respectively. Mean urinary fluoride values at Site 3 were within the normal urinary fluoride reference value range in spite of pervasive severe pitting fluorosis. Meal and magadi analyses revealed widely varied fluoride concentrations. Concentrations ranged from 0.01 to 22.04 mg/L F for meals and from 189 to 83211 mg/L F for magadi. Complete element analysis revealed the presence of aluminum, iron, magnesium, manganese, strontium and titanium in four magadi samples. There were much higher concentrations of these elements in samples from Site 3, which was at the highest altitude and had severe enamel disturbances in spite of negligible water fluoride concentration. An analysis of covariance model supported the research hypothesis that the three communities differed significantly in mean fluorosis scores (P<0.0001). Controlling for urinary fluoride concentration and urinary fluoride:urinary creatinine ratio, location appeared to significantly affect fluorosis severity. Urinary fluoride:urinary creatinine ratio had a stronger correlation than urinary fluoride concentration with mean TFI fluorosis scores (r=0.43 vs r= 0.25). CONCLUSIONS: The severity of enamel disturbances at Site 3 (1463 m) was not consistent with the low fluoride concentration in drinking water, and was more severe than would be expected from the subjects' normal urinary fluoride values. Location, fluoride in magadi, other elements found in magadi, and malnutrition are variables which may be contributing to the severity of dental enamel disturbances occurring in Site 3. Altitude was a variable which differentiated the locations.

Two types of intraoral distribution of fluorotic enamel.

Different distributions of fluorotic dental enamel within the dentition have been described in the literature. This report describes two patterns of intraoral distribution. In nine Tanzanian low fluorosis communities with a prevalence of pitting fluorosis of less than 2% and in five moderate fluorosis communities with a prevalence of pitting fluorosis of 16-59%, incisors and first molars were the least affected teeth. In four high fluorosis communities with a prevalence of pitting fluorosis of 86-97%, maxillary incisors exhibited lower Thylstrup-Fejerskov Index values than the maxillary canines, premolars and molars. The mandibular teeth exhibited increasing Thylstrup-Fejerskov Index values from the anterior to the posterior region. The curves presenting the intraoral distribution of the severity of dental fluorosis corresponded with the curve presenting the completion time of primary enamel formation of the various tooth types, with the exception of the first molars in high fluorosis communities. The similarity of the curves suggests that the later in life enamel is completed, the higher is the severity of dental fluorosis. This relation seems to be explained by the prevailing feeding and dietary habits, which result in minimal intake of fluoride in the first 18 months of life during breastfeeding, followed by increasing fluoride ingestion in the following years through consumption of tea, seafish and F-containing magadi salt.

Dental fluorosis and the use of a high fluoride-containing trona tenderizer (magadi).

It has recently been suggested that magadi, a high-fluoride trona, which is added in cooking to tenderize certain vegetables and beans in two villages in Tanzania, significantly contributed to the prevalence and severity of dental fluorosis. This report aims to substantiate the significance of magadi as a determinant of dental fluorosis. Eighteen villages in four geographical areas (districts) with water supplies containing 0.2 to 0.8 mg/L of fluoride were selected. All schoolchildren aged 12 to 17 years (n = 1566) who had been born and raised in these villages were examined for dental fluorosis according to the Thylstrup-Fejerskov Index. Dietary history was recorded. The fluoride content of magadi samples was determined and the urinary fluoride excretion of pre-schoolchildren was assessed. The prevalence of dental fluorosis in nine coastal villages where tea and seafish were regularly consumed ranged from 7% to 46%. Severe (pitting) dental fluorosis was rarely seen. The low fluorosis levels observed in non-magadi consuming communities in coastal villages indicate that a fluoride content of up to 0.8 mg/L in drinking water is acceptable under the prevailing conditions of temperature and diet. In contrast, the prevalence of dental fluorosis in nine villages located inland at 1500 m altitude, where fluoride-containing magadi was consumed, ranged from 53% to 100%, and severe (pitting) fluorosis was highly prevalent, ranging from 18% to 97%. The village with the highest fluoride content in the magadi samples collected showed the highest level of fluorosis. The urinary fluoride excretion of pre-schoolchildren from different villages corresponded with the level of fluorosis and the fluoride content in the magadi samples of the respective villages. Data on dental fluorosis from the magadi-consuming communities provide strong evidence that consumption of magadi was the major determinant of the observed high prevalence and severity of fluorosis in inland villages at 1500 m altitude.

Comparison of two indices of dental fluorosis in low, moderate and high fluorosis Tanzanian populations.

This study aimed at comparing the Thylstrup-Fejerskov index (TFI) and the Dean's Index (DI) which were applied on three communities with different severity of dental fluorosis. A total of 1565 children aged between 11 and 18 yr with a mean age of 14.7 were examined for dental fluorosis with the TFI and 1155 of these children were also examined with the DI. The measurement error for the TFI was 0.50 (10 scale point) compared to 0.53 for DI (6 scale point). The Kappa values and the measurement-remeasurement correlation appeared to be better for the TFI. No difficulties were encountered in applying the TFI in contrast to the DI, which caused uncertainties in assessing the "questionable" and "very mild" scores, and this may explain the relatively better reproducibility of the TFI. The correspondence between both indices was determined. TFI 0 corresponded well with DI 0. The conversion values for TFI 1, 2, 3 and 4 into DI scores were 0.3, 0.8, 1.4 and 2.4 respectively. The TFI 5-9 corresponded with DI score 4. TFI could discriminate the severe forms of dental fluorosis which were categorized in Dean's highest score 4. TFI was able to reveal more dental fluorosis than DI in communities with minor and moderate dental fluorosis. In the community with severe dental fluorosis where more than 85% of all teeth exhibited a DI > or = 1, both indices revealed a comparable prevalence of dental fluorosis. The TFI is considered a near ideal instrument.

Dental caries; plaque; calculus and gingival bleeding in 14-17 years old secondary school scholars in Morogoro; Tanzania

The present study is on oral health conditions of 319 Tanzanian secondary school scholars; aged 14-17 years. The prevalence of caries was 51 per cent. The mean DT; MT and FT-score was 1.10; 0.22 and 0.03; respectively. Girls had significantly higher caries levels than boys (p = 0.005). Missing teeth were observed in 14 per cent of the scholars examined. Occlusal surfaces were the surfaces most affected and the molars the most affected tooth type. The prevalence of heavy plaque (score = 2); calculus and gingival bleeding was 42 per cent; 82 per cent and 44 per cent respectively. Boys had higher percentages of all sites covered with plaque; calculus and gingival bleeding than girls. The present survey amongst 14-17 years olds revealed a much higher caries experience and a higher prevalence of missing teeth due to caries than reported amongst 12-yr-old Tanzanian children. Since Tanzania has a population-based preventive strategy targeted at 0-15-yr olds; it is suggested monitoring changes in oral health conditions at the age of 15 instead of 12 years

Effects of two oral health care programmes on the prevalence of dental caries amongst secondary school scholars in Tanzania after 22 months

The effect of a comprehensive oral care and oral education field programme on the oral health status of secondary school scholars was tested in Morogoro; Tanzania. The programmes were carried out by dental students. After 22 months; the mean DMFS increment score was higher for the control group than for the two test groups; but the difference observed was not statistically significant. The final examination after 4 years could not be carried out

Prevalence of dental caries in 7-13-yr-old children in Morogoro District, Tanzania, in 1984, 1986, and 1988.

A 4-yr mixed-longitudinal study to determine the prevalence of caries in 7-13-yr-old Tanzanian children was started in 1984. The parameters considered were age, locality, Socio-Economic Status, and sex. Locality was composed of urban (Morogoro town), rural (Morogoro District), and rural areas in the District with an average fluoride level of 0.5 ppm or more in all drinking water present. SES was established based on the occupation of the father or mother and on housing conditions. Overall, the reproducibility of the dental conditions studied (D2MT/S and D3MT/S) was high, with lower scores for the conditions including early enamel lesions (D3MT/S). The reproducibility of the SES scoring system was high (kappa = 0.96 and kappa = 0.90), but the association over the 2 yr of measurement (1984 and 1988) was weak (r = 0.50). There were no restorations found. The percentage of children with caries increased with increasing age from 12-17% at age 7 to 37% at age 13. The statistical tests (ANOVA) revealed an age effect for all conditions studied in 1984, 1986, and 1988 and a locality effect in 1988 only. The mean D3MT-scores varied between 0.15 and 0.24 at age 7 to 0.76 at age 13, while the mean D3MS-scores varied between 0.27 and 0.31 at age 7 to 1.18 at age 13. In general, the caries prevalence observed was low. Children living in naturally fluoridated rural areas had significantly lower caries scores than children in non-fluoridated areas.