The effectiveness of early intervention on malocclusion and its impact on craniofacial growth: A systematic review

This review aims to assess the available evidence related to the effectiveness of early interventions on malocclusion and its impact on the craniofacial structure among children under six years of age. Furthermore, we aimed to evaluate the correlation between nutritive sucking behavior mechanisms on the oral facial components. We searched Medline, Embase, Cochrane Library, Scopus, and the LILACS from inception to December 10, 2020, to identify published randomized and non-randomized controlled trials that investigated the broad spectrum of early interventions for the treatment of malocclusions among pediatric patients under six years old. We have also included studies that evaluated the impact or the relationship between feeding alternatives, malocclusion, and craniofacial growth. Reviewers working in pairs investigators independently performed title and abstract screening, full-text screening, data extraction, risk of bias assessment using ROBINS-I tool, and rated the certainty of evidence using GRADE. Seven studies were included (783 patients), with an overall risk of bias classified as critical. Early treatment was shown to improve facial asymmetry, particularly in the lower part of the face, along with an increase of palatal volume and palatal surface. Early treatment showed important reduction of mandibular protrusion and length, leading to favorable sagittal growth of the maxilla. Furthermore, the early intervention significantly enhanced the average bite force magnitude (from 318.20 N to 382.79 N) and increased the general thickness of facial muscles. Our findings suggest that the benefits generated by early orthodontic interventions are related to the improvement of craniofacial symmetry/bone structure, and refinement of masticatory ability and performance. Notwithstanding, there is still a need for further studies appraising patientimportant outcomes, such as quality of life and nutritional features.