Validation of the Mirror-Fogging Test as a Screening Tool for Velopharyngeal Insufficiency

Purpose: Comprehensive evaluation of velopharyngeal insufficiency (VPI) typically includes auditoryperceptual assessment, nasometry, and anatomical evaluations. At times, these examinations are limited by the resources, invasiveness, time and expertise required to perform them. In such instances, the mirror-fogging test would be an ideal screening tool for VPI as it can be performed simply and quickly with minimal resources. However, the sensitivity and specificity of this screening tool have yet to be documented. This study sought to validate the mirror-fogging test as a screening tool for VPI when compared to auditory-perceptual assessments and nasometry. Methods: The charts of 60 participants from our VPI clinic at a tertiary care hospital were retrospectively reviewed: 40 exhibited VPI and 20 were negative for VPI according to auditory-perceptual testing and nasometry. Nasometry scores identified a priori as two standard deviations above normal were judged to be diagnostic for VPI. Auditory-perceptual testing was deemed diagnostic for VPI with hypernasality and audible emission scores above 1 using the American Cleft Palate Association (ACPA) clinical scale for VPI. The sensitivity and specificity for the mirror-fogging test was determined using auditory-perceptual testing and nasometry as diagnostic standards. Results: The mirror-fogging test had a sensitivity of 0.95, a specificity of 0.95 and a positive predictive value of 0.97. Significantly higher auditory-perceptual scores were demonstrated for the features of hypernasality (p <0.008), audible nasal emission (p <0.001), and velopharyngeal function (p <0.001) in the mirror-fogging test positive group. Conclusion: The mirror-fogging test is highly correlated with both auditory-perceptual speech assessment and nasometry, thus, validating its utility as a screening tool for VPI.