Association between atypical swallowing and malocclusions: a systematic review.

Objective: This systematic review aims to answer the following focus question: "Is there an association between atypical swallowing and malocclusions?".

Methods: Appropriate word combinations were chosen and tailored specifically for each of the following electronic databases: EMBASE, Latin American and Caribbean Literature in Health Sciences (LILACS), LIVIVO, PubMed/Medline, Scopus, Web of Science, and gray literature, without any restrictions, up to February 2021. According to the selection criteria, only cross-sectional studies were included. The following inclusion criteria were considered: a sample composed of children, adolescents, and adults; patients clinically diagnosed with atypical swallowing; patients with normal swallowing; and outcome of interest of atypical swallowing in patients with malocclusion. The data consisted of study characteristics, sample characteristics, results, and conclusion of each study. The risk of bias was assessed using the JBI Critical Appraisal Checklist for Analytical Cross-Sectional Studies, and the certainty of evidence was assessed using the GRADE tool.

Results: 4,750 articles were identified. After a two-step selection, four studies were included. A higher frequency of distal occlusion, extreme maxillary overhang, and open bite was related to swallowing disorders; most studies pointed to posterior crossbite as a malocclusion more associated with atypical swallowing. All studies had a moderate to high risk of bias, and the certainty of evidence was very low.

Conclusion: The results indicate that atypical swallowing is associated with malocclusions and that posterior crossbite is the main malocclusion found, but only in the young population (3-11 years).

Registration: PROSPERO (42020215203).