Evaluation of uvulo-glosso-pharyngeal changes after the functional appliance therapy: a cephalometric study

Introduction: Functional appliances are mostly used in the modulation of mandibular growth and displacement of the tongue, which results in the alteration of the oropharyngeal airway. This study was carried out to evaluate the cepalometric changes in pharyngeal airway space along with the position of hyoid bone, size and position of tongue and soft palate after functional appliance therapy in growing patients. Aims and objectives: 1.To evaluate the changes in pharyngeal length and width 2.To evaluate hyoid bone position and angulation, and 3. To compare size of tongue and soft palate before and after functional appliance therapy. Materials and method: The pretreatment and post treatment cephalometric radiograph of 8 growing subjects were considered and the changes in the airway were analyzed by dividing the sample in pretreatment (Group 1) and the post treatment group (Group 2). Cephalometric readings were analyzed using Paired t test and Pearsons correlation to evaluate the changes in the dimensions of pharyngeal airway, position and angulation of hyoid bone, length and width of soft palate and tongue. Results: Statistically significant changes were found in the anterioposterior dimensions of hypopharyngeal airway space (p=0.004) and hyoid distance from mandibular plane (p=0.046) after the completion of functional appliance therapy. Conclusion: The functional appliances play a significant role in the improvement of hyphopharyngeal airway space and in the upward movement of the hyoid bone in relation to the mandibular plane, increasing the area of the lower airway and hence decreasing the lower airway resistance.