Does Notching Along the Nasal Velar Surface During Nasopharyngoscopy Predict Discontinuity of the Underlying Levator Veli Palatini Muscle?

Abstract

To determine the sensitivity and specificity of velar notching seen on nasopharyngoscopy for levator veli palatini (LVP) muscle discontinuity and anterior positioning. Nasopharyngoscopy and MRI of the velopharynx were performed on patients with VPI as part of their routine clinical care. Two speech-language pathologists independently evaluated nasopharyngoscopy studies for the presence or absence of velar notching. MRI was used to evaluate LVP muscle cohesiveness and position relative to the posterior hard palate. To determine the accuracy of velar notching for detecting LVP muscle discontinuity, sensitivity, specificity, and positive predictive value (PPV) were calculated. A craniofacial clinic at a large metropolitan hospital. Participants Thirty-seven patients who presented with hypernasality and/or audible nasal emission on speech evaluation and completed nasopharyngoscopy and velopharyngeal MRI study as part of their preoperative clinical evaluation. Among patients with partial or total LVP dehiscence on MRI, presence of a notch accurately identified discontinuity in the LVP 43% (95% CI 22-66%) of the time. In contrast, the absence of a notch accurately indicated LVP continuity 81% (95% CI 54-96%) of the time. The PPV for the presence of notching to identify a discontinuous LVP was 78% (95% CI 49-91%). The distance from the posterior edge of the hard palate to the LVP, known as effective velar length, was similar in patients with and without notching (median 9.8 mm vs 10.5 mm, P = 1.00). The observation of a velar notch on nasopharyngoscopy is not an accurate predictor of LVP muscle dehiscence or anterior positioning.