The speech therapy has been associated with orthodontic treatment of anterior open bite in order to promote muscle fitness and stomatognathic functions. Despite positive reports, it still requires scientific evidence of therapeutic programs. Objectives: To propose and analyze the effectiveness of orofacial myofunctional therapy program (OMT), of the for children with anterior open bite. Method: Clinical study with therapeutic intervention. Subjects: The study included 50 children in mixed dentition, aged 6-11 years (8.96 ± 1.45). Twentyeight subjects with anterior open bite (MAA group), 16 classified as dental alveolar MAA (8.93 ± 1.48), and 12 as skeletal MAA (9.00 ± 1.41) in orthodontic treatment in Clinic of Preventive Orthodontics, University of São Paulo, school of Dentistry of Ribeirão Preto, (FORP-USP). Twenty-two children, paired for age and sex, with normal occlusion participated in the control group (C group). All perform radiographic examination for cephalometric analysis, surface electromyography (EMG) of the temporal muscles, anterior bundle, and masseter; anthropometric measurements and pressuretongue and lip strength, and orofacial myofunctional evaluation with score (OMES). After the OMT program, the children of the MAA group were reassessed using the same methods except the radiographic. The data were analyzed by the Mann-Whitney test for unpaired samples (for comparison of data from MAA and C groups), and the Wilcoxon test for paired samples (to compare the data from MAA group before and after OMT). Results: Positive changes in the musculature and stomatognathic functions after OMT for the overcoming of differences between MAA and C groups.Compared to the stage before OMT, after therapy MAA group increased muscle activity, reducing the asymmetry of the temporal muscles, and overcome the prevalence of temporal muscles on the masseter muscles; increased tongue capacity to produce pressure; reducing the average pressure exerted by the lips; increase in scores of categories appearance / posture and mobility, as well as swallowing, chewing and total score of OME-expanded protocol all with P< 0,05. Conclusion: The OMT program used was effective and contributed to the appearance, posture and orofacial motor control in subjects with MAA during orthodontic treatment. Influenced the treatment results the age of the children and the orofacial myofunctional condition before OMT.