Oral myofunctional and electromyographic evaluation of the anterior suprahyoid muscles and tongue thrust in patients with Class II/1 malocclusion submitted to first premolar extraction

OBJECTIVE: The aim of this study was to assess the existence of myofunctional alterations before and after first premolar extraction in Class II/1 malocclusion patients that could endanger the long-term dental arch stability. MATERIAL AND METHODS: The study was performed by means of morphological, functional and electromyographic analyses in 17 Class II/1 malocclusion patients (group T) and 17 Class I malocclusion patients (group C), both groups with 12-30-year age range (mean age: 20.93 ± 4.94 years). RESULTS: Data analyzed statistically by Student's t-test showed a significant decrease in the maxillary and mandibular dental arch perimeters after orthodontic treatment (p;0.05). However, group T differed significantly from group C (