Comparative analysis of velopharyngeal activity assessed by acoustic rhinometry, rhinomanometry and videofluoroscopy

Abstract

Acoustic rhinometry is a well-known technique for the assessment of nasal and nasopharyngeal geometry and patency, providing graphical data on cross-sectional areas and volumes. As part of a broader project, developed at the Laboratory of Physiology, USP Hospital for Rehabilitation of Craniofacial Anomalies, in which we have been investigating the efficiency and applications of the technique in the diagnosis of velopharyngeal insufficiency (VPI), this study will analyze, by means of acoustic rhinometry, the VP activity in patients with repaired cleft palate and clinical diagnosis of VPI, as compared to the activity measured by modified anterior rhinomanometry and videofluoroscopy, used as direct and indirect reference methods, respectively. Nasopharyngeal volume will be determined during rest (voluntary interruption of breathing) and during specific speech samples (maximal velopharyngeal activity) using an Eccovision Acoustic Rhinometer (Hoods). Nasopharyngeal volume change caused by VP activity will be analyzed by calculating the absolute and relative difference between speech and rest volumes (”V=VS-VR and ”V=VS-VR/VR, respectively). To validate the technique, the volumetric variable will be compared with indicators of speech VP activity measured by modified anterior rhinomanometry (VP orifice cross-sectional area) and videofluoroscopy (VP gap, velar elevation and pharyngeal walls movement, tongue involvement). The main goal of this study is, therefore, to introduce a new method of assessment of VP function among the routine tests available for diagnosing VPI and monitoring of outcomes of therapeutic interventions in patients with cleft palate.