Facial growth direction after surgical intervention to relieve mouth breathing: a systematic review and meta-analysis.

OBJECTIVES: A systematic review was performed to assess the prognosis for facial growth direction documented by mandibular plane inclination and anterior face height in growing subjects who had undergone surgical intervention to relieve mouth breathing (PROSPERO database, registration no. CRD 42013005707).

METHODS: PubMed, Scopus, Web of Science, the Cochrane Library and LILACS were searched based on the guidelines of the PRISMA statement. Included were longitudinal studies with mouth-breathing patients who had undergone surgical interventions to relieve their respiratory pattern, with a minimum follow-up of one year.

RESULTS: A total of 1555 studies were identified, whereby only three nonrandomized clinical trials comprising 155 participants met the inclusion criteria. Primary outcome was change between the initial and final measurements of the mandibular plane-SN angle (95% confidence interval [CI] -2.13° [-3.08, -1.18]). Secondary outcomes included changes in total anterior face height (AFH; 95% CI -0.76 mm [-1.91, 0.38]), upper AFH (95% CI 0.09 mm [-0.57, 0.74]), and lower AFH (95% CI 0.06 mm [-0.87, 0.99]). Risk of bias was low for most of bias domains and the quality of evidence across the studies was considered to be very low. The design, the small number of participants, and the absence of blinding generated imprecision.

CONCLUSIONS: There is very low evidence that the mandibular growth direction became more horizontal during the first year after surgery to treat mouth breathing. The total anterior facial height decreased, although not always significantly.