Study Of Caries Experience And The Cariosity Of Dental Plaque In Children With Cleft Lip And/or Palate

Objective: To determine the levels of dental caries and the cariosity of dental plaque in subjects with cleft lip and palate in China.Method: (1) A total of 380 subjects with cleft lip and palate, and 339 noncleft control subjects were examined for dental caries by using the decayed-missing-filled-teeth (DMFT/dmft) index. And a short questionnaire was given to parents of the children. The form included questions about children's living habits and socio-economic status of their families.(2) 20 cleft children and 20 noncleft children (aged 3-5 years) were selected randomly. The pHrest of dental plaque and its change were determined in situ with a pH microelectrode within lh after sucrose rinsing. Then the supragingival plaque samples were taken from subjects respectively. The acids contents, including formic acid, acetic acid, lactic acid, and succinic acid in plaque fluid were determined by high performance liquid chromatography. RT-PCR with specific primer technology is used to detect the prevalence rates and quantity of caries-associated microflora (Streptococcus mutans and Lactobalilus).Results: (1) Caries prevalence and score for dmft/DMFT and dmfs/DMFS were significantly higher in children with cleft palates than in control subjects(P＜0.05), except 3-to 5-year-old children(P＞0.05).However, in 3-to 5-year-old group, children with cleft lip and palate had significantly more caries than children of the same age with only a cleft lip or a cleft lip and alveolus (P＜0.05). And children whose clefts had been surgically repaired had a lower dmft than those who hadn't surgically repaired their clefts (P＜0.05).The factors for dental caries were: type of cleft, age, the educational level of the parents, frequency of toothbrushing and eating habit.(2) There were significant differences on the pHrest, pHmin,△pH, and AUC30 between cleft children and noncleft children, except△pH in the submaxilla.(3) Content of lactic acid in plaque fluid was different between two groups, but the concentrations of formic acid, acetic acid and succinic acid were not significantly between the groups of children.(4) The cleft palate children had higher levels of Streptococus mutans and Lactobacillus, but the prevalence of them and the proportion of Streptococcus mutans in total bacteria were not difference between two groups.Conclusion: (1) Chinese children with oral cleft are at an increased risk for dental caries. Types of cleft, the surgical repair, age, and the educational level of the parents are important factors for dental caries.(2) The cleft palate children had lower plaque pH value and higher content of lactic acid and levers of Streptococcus mutans and Lactobacillus than control children. The cariosity of plaque in children with cleft lip and/or palate is greater than nocleft subjects.