[Dental caries in schools in the city of N'Djamena in Chad: Epidemiological aspects and oral habits in pupils aged from 6 to 12 years].

Background: Dental caries is a global disease that can have disabling effects. In Africa, its prevalence in schools is very variable, due to the great variability of food habits and oral hygiene. This study aimed to assess the prevalence of dental caries, associated factors, and to research oral pathologies associated with that dental decay in one circumscription of the city of N'Djamena.

Material and methods: This was a cross-sectional study conducted in 3 schools in the 7th borough of the city of N'Djamena. A total of 360 pupils aged between 6 and 12 years were recruited between October 2021 and September 2022. Each participant underwent to an oral examination which consisted in looking carefully at the pupil's face (cheeks, lips) to note any deformities or possible facial asymmetry, and to check for any sensation of pain in any part of the face. In another hand, the oral examination aimed to look for any decay on all the teeth and determine the category and class of it. Finally, the personal data (age, sex, class, parents' occupations) of each participant and the results of his oral examination were collected into a database and analyzed.

Results: A total of 185 pupils had at least one decayed tooth, giving a prevalence rate of 51.4%. Among them, 45% had at least 2 decayed teeth. The school attended and snacking between meals were significantly associated with the presence of caries (p<0.05). Teeth 36 (lower left first molar) and 46 (lower right first molar) were the most often affected by caries (21% and 22% respectively). The mixt DMF index was 0.6 and the overall frequency of decayed teeth was 51.9%. According to Black's classification, class II caries was the most prevalent (48%), while according to Baume's classification, category II was the most prevalent (54%). The time of brushing, the material and the type of product used significantly influenced the appearance of caries (p<0.05). Participants with dental dyschromia had more tooth decay.

Conclusion: Caries was prevalent in the targeted schools and represented a real problem for pupils. Implementing an oral health policy based on preventive dentistry by raising awareness among children and their parents would contribute to the proper education of pupils.