Relapse of anterior open bites treated with orthodontic appliances with and without orofacial myofunctional therapy.

INTRODUCTION Closure and long-term retention of anterior open bites are significant concerns for orthodontists and their patients. In this study, we investigated the efficacy of orofacial myofunctional therapy (OMT) for maintaining closure of open bites in conjunction with orthodontic treatment. METHODS The sample included 76 subjects with dental anterior open bites referred for OMT before, during, or after relapse of orthodontic treatment. The experimental cohort consisted of 27 subjects who received OMT and orthodontic treatment or retreatment. The control cohort comprised 49 subjects who had a history of orthodontic treatment with open-bite relapse. Overbite was evaluated by an OMT professional or orthodontist 2 months to 23 years after removal of the fixed appliances. Measurements were compared with t tests. RESULTS Overbite relapse means were 0.5 mm (range, 0.0-4.0 mm) in the experimental group and 3.4 mm (range, 1.0-7.0 mm) in the control group, a difference that was clinically and statistically significant (P <0.0001). CONCLUSIONS This study demonstrated that OMT in conjunction with orthodontic treatment was highly effective in maintaining closure of anterior open bites compared with orthodontic treatment alone.