Evaluation of Upper and Lower Pharyngeal Airway and Hyoid Bone Position in Skeletal Class II Patients Treated with Forsus and Powerscope Appliance: A Prospective Study

Abstract

Objectives: To assess and compare the change in pharyngeal airway dimensions and hyoid bone position also to evaluate the skeletal and dental effects of Forsus and Powerscope appliance in skeletal Class II malocclusion patients with obstructive sleep apnea subjected to 6 months fixed functional appliance therapy. Methods: 30 patients with skeletal class II malocclusion having day-time somnolence associated with snoring requiring fixed functional orthodontic treatment were selected and randomly divided into Forsus and Powerscope groups. Patients were treated with MBT 0.022-slot and aligned till 19x25 SS. Fixed functional appliance was installed. Digital Lateral cephalograms were traced for Skeletal, Dental, Airway Measurements and Hyoid bone position at pre-treatment (T1), before start of fixed functional therapy (T2) & at end of fixed functional therapy (T3) analysed using Dolphin software. Findings : Skeletal correction achieved was same for both Forsus and Powerscope. Forsus showed significant improvement in sagittal correction whereas Powerscope produced dentoalveolar changes. Airway dimensions showed significant increase Pre & Post treatment for both groups. Whereas Hyoid Bone moved more mesial and superior with fixed functional therapy. Change in airway dimensions was similar for both the groups. Fixed functional appliance produced significant increase in airway dimension however no difference seen between Forsus and Powerscope. Novelty: The study revealed that correction of mandibular retrusion using mandibular advancement appliances in skeletal class II malocclusion with obstructive sleep apnoea increased the airway dimensions and improved nasal breathing. The dimension of upper and lower airway increased significantly. Keywords: Fixed Functional Appliance; Forsus; Powerscope; Hyoid Bone; Airway