Criteria for assessing malocclusion in the mixed dentition in epidemiological studies: A scoping review

Malocclusion in mixed dentition is highly prevalent, and this phase has specific characteristics that hinder its epidemiological assessment and the standardization of diagnostic criteria.

To map the criteria used to assess malocclusion in mixed dentition in epidemiological studies, identify reported results, and point out existing methodological gaps.

In 2025, an exploratory review was conducted in accordance with the recommendations of the Joanna Briggs Institute and the PRISMA-ScR checklist. The guiding question was constructed based on the PCC (Population: children; Concept: criteria for assessing malocclusion; Context: mixed dentition). Searches were conducted in PubMed, MEDLINE, Scopus, Embase, Web of Science, and LILACS databases, as well as pre-registration platforms and grey literature. Primary studies in English, Portuguese, or Spanish were included without year restrictions.

A total of 3,210 studies were identified, of which 58 met the inclusion criteria. There was considerable heterogeneity in the criteria used, with a predominance of indices originally developed for permanent dentition, such as the Dental Aesthetic Index (DAI) in 13 studies and the Index of Orthodontic Treatment Need (IOTN) in 18 studies.

The absence of a standardized and widely validated approach for assessing malocclusion in mixed dentition compromises data comparability and may limit diagnostic accuracy in epidemiological studies. Although several assessment methods have been proposed, further studies are needed to determine whether adapting existing indices or developing new assessment tools would provide a more appropriate approach for this developmental stage.