Effects of dietary consistency on the occlusal changes in nonhuman mammals: A systematic review

This systematic review aimed to assess whether hard or soft foods interfere with the pattern of occlusal changes in nonhuman mammals.

The electronic databases PubMed, Scopus, Web of Science, Cochrane Library, LILACS, OpenGrey and Google Scholar were examined. Only studies investigating the effects of dietary consistency on the occlusal characteristics in animal models were included. The risk of bias was performed based on the SYRCLE's tool, which assigned a low, high or uncertain assessment to each domain.

After the removal of duplicates, a total of 8,977 articles remained. From those, 19 studies met the eligibility criteria. Although a great methodological heterogeneity was observed, the results of the included studies as a whole points to homogeneity in the findings obtained on rats, pigs, and monkeys. The increase in the masticatory load was associated with larger dental arch dimensions. Dental wear and dento-alveolar changes were more evident with an increase of diet consistency. Baseline characteristics, blinding of outcome assessors, other sources of bias, incomplete outcome data, and selective outcome reporting were best assessed, denoting a lower risk of bias. In sequence generation and allocation concealment, insufficient details were provided to improve the classification. Random housing and outcome assessment and blinding of researchers were poorly evaluated.

Considering the limited evidence obtained from these findings, it seems that food consistency may interfere with the development of occlusal patterns and arch dimensions among growing animals. The findings suggest an environmental effect, even if minimal, on the occlusal characteristics.