Upper Airway Changes After Xbow Appliance Therapy Evaluated With Cone Beam Computed Tomography

Abstract

Objective: To determine the treatment effects of the Xbow appliance on the upper airway dimensions and volume using cone-beam computed tomography (CBCT); to evaluate the cephalometric changes in the skeletal and dental structures of the skeletal Class II patients. Materials and Methods: The sample consisted of 25 Class II patients (11 male, 14 female) with a mean age of 11.1 +/- 1.1 years. CBCT images were obtained at the beginning of the treatment (TO) and after the debonding of the Xbow (T1). Results: Changes in superior, middle, and inferior parts of the oropharynx in the retroglossal region and changes in the oropharyngeal airway volume were statistically significant (P < .05, P < .01). The differences favoring the Xbow for the changes in the direction of Class II correction included SNA, SNB, ANB, maxillary depth angles, and point A-NPg and Co-B distances. Data of the dental parameters showed palatal tipping and extrusion of the maxillary incisors, labial tipping of the mandibular incisors, and mesial movement and extrusion of the mandibular molars. Conclusions: Treatment with the Xbow appliance in Class II patients resulted in favorable increase in the oropharyngeal airway dimensions and volume. Further studies with larger study samples and with control groups are needed.