Dental caries experience, care index and restorative index in children with learning disabilities and children without learning disabilities: a systematic review and meta-analysis.

Data sources MEDLINE, PubMed, Scopus and Web of Science.Study selection Two reviewers independently selected observational studies which compared caries experience between children with learning disabilities (CLD) and children with no learning disabilities (CNLD). Data extraction and synthesis DMFT/dmft, Care Index (CI) and Restorative Index (RI) data was extracted from each study. Meta analyses were conducted on the overall data and then on the following subgroups: Down's syndrome, autism and mixed learning disabilities. An adapted Newcastle-Ottawa Scale (NOS) was used to assess bias. Results Twenty five comparative cross sectional studies from eighteen countries were included in the review. The standardised mean difference in DMFT between CLD and CNLD was 0.43 (95% CI; 0.91 to 0.05 I² >95%) and for dmft was 0.41 (95% CI; 0.14 to 0.96 I² >95%). The only significant difference revealed by sub group analyses of the three main disability groups was lower caries experience in the permanent dentition of children with Down's syndrome (SMD = 0.73; 95% CI; 1.28 to 0.18). There was a larger difference between mean CI and mean RI for CLD than for CNLD, however, the standard deviations were large and no variance data was provided so meta-analyses could not be completed.Conclusions Overall there was no difference in caries experience between CLD and CNLD. However, sub group analysis showed that children with Down's syndrome had lower levels of caries than CNLD but this may be due to the delayed eruption of the permanent teeth commonly seen with Down's syndrome. There was limited data suggesting that caries in permanent teeth was more commonly treated by extraction in CLD than in CNLD, however, this was based on only eight studies.