Changes of Oropharynx Space and Posterior Surface of the Tongue Following Treatment with Farmand Functional Appliance

Statement of Problem: During treatment with functional appliance in patient with class II division I malocclusion, mandible is postured inferiorly and anteriorly. Considering the relation between mandible with tongue and oropharynx space, functional appliance therapy can alter the tongue position and oropharynx space. This study aimed to determine the changes of oropharynx space and posterior surface of the tongue position following treatment with Farmand functional appliances in patients with class II division I malocclusions. In this clinical trial study, 28 pre and post treatment cephalometric radiographs of patients with class II division I malocclusions were investigated. The age rang of females was 10-13 years and in males it was 11-14 years. The patients were treated by Farmand functional applicne for 11 months. McNamara analysis and some linear variables were used to determine the positional changes of tongue and oropharynx space. Paired-t test was used to compare the pre and post treatment differences of mean values. Variance analysis was used to compare the growth patterns of the patients. Tongue moved significantly forward (p<0.001) but non–significantly downward. Oropharynx space increased significantly in sagittal dimension (p<0.001). There was a significant correlation between decrease of ANB angle with forward movement of tongue (p<0.05) as well as with the increase in extent of oropharynx space in the sagittal dimension (p<0.05). Treatment with Farmand functional appliance showed significant alteration in tongue position and as a result, increased the extent of oropharyngeal space.