ABSTRACT
The objectives of this cross-sectional study were to determine the prevalence of caries, severe caries and gingivitis in Tehran primary-school children and to analyse the relationship between children's oral hygiene habits and prevalence of these oral health diseases. Data were collected on the oral hygiene habits of 1271 Tehran schoolchildren [637 boys, 634 girls] aged 9-13 years. Clinical examinations were performed to determine the decayed, missed and filled teeth [DMFT] and the presence of gingivitis. Total DMFT >/= 1 was observed in 83.3% of children; 55.5% had tDMFT >/= 4 and 87.7% had >/= 1 site affected by gingivitis. Dental visits of 48.2% of children were limited to toothache occasions and parents' lack of belief in the importance of oral health was the most commonly cited reason [P