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. (Am J Orthod Dentofacial
Orthop 2010;137:605-14)