Forward movement of posterior pharyngeal wall on phonation.

Forward movement of the posterior pharyngeal wall on phonation is divided into 2 types. One is movement of Passavant's ridge, which is a crescent-shaped or shelf-like posterior pharyngeal structure, and the other is generalized forward movement, which is not sharply outlined, of the posterior pharyngeal wall. Although nasopharyngoscopic and multiview videofluoroscopic findings on their movement show that they are markedly different, there are few reports about differentiation between them. In this study, multiple cross-sectional observations with rapid magnetic resonance imaging were performed to elucidate the forward movement of the posterior pharyngeal wall on phonation. I used rapid MRI to examine 4 subjects (3 females and 1 male) who had forward movement of the posterior pharyngeal wall with or without Passavant's ridge. Judging from the findings and local morphology, Passavant's ridge consisted of pharyngeal mucous and/or pharyngeal superficial muscles. On the other hand, it was revealed that generalized forward movement of the posterior pharyngeal wall was caused by contraction of the longus capitis muscle. The longus capitis muscle is well known as a flexor muscle of the head. The findings of the present study are significant and useful in speech rehabilitation for patients with velopharyngeal insufficiency.