Dentoalveolar alterations after interventions to relieve mouth breathing : Systematic review and meta-analysis.

Background: Mouth breathing is related to morphological and functional alterations in growing individuals. Understanding early events that can lead to these changes can prevent or decrease the need for orthodontic treatment.

Objective: The goal was to assess the prognosis for dental alterations evidenced by changes in the incisor inclination and arch width after surgical intervention to normalize the mode of breathing in growing patients.

Data sources: Databases were searched based on the guidelines of the Preferred Report Items for Systematic Reviews and Meta-Analysis (PRISMA statement), with no restrictions on language or year of publication.

Study selection: Seven non-randomized studies were selected, with follow-up times ranging from 12 to 60 months. Differences in the inclination of the upper and lower incisors, intercanine and intermolar maxillary widths between the initial and final measurements were the primary and second outcomes.

Data extraction: Two independent authors extracted the data independently. The Quality in Prognosis Studies tool (QUIPS tool) and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) were used to assess the risk of bias and the quality of evidence.

Data synthesis: Although four studies presented a similar methodology and significant results regarding incisor inclination, the meta-analysis did not provide statistical evidence favoring surgical interventions for these variables (p = 0.12). No significant changes in the transverse dimension of the maxillary arch were found in the primary dentition (95% confidence interval [CI], 0.231 [-0.394/0.857], p = 0.4690).

Conclusions: Four separate studies provided acceptable but low evidence that interventions to relieve mouth breathing in growing individuals favor normalization of lower incisor inclination. In the primary dentition, no significant changes were found in the arch width.