Identification of the opener and closer of the pharyngoesophagus in laryngectomees

Background: In esophageal and tracheoesophageal speakers, the neoglottis ac ts not only as the orifice of the digestive tract but also as the airway an d the Voice source. The opening and closing mechanism is thought to be esse ntial for these functions. It is not known, however, whether there is any a ctive muscular control of neoglottal opening and closing. Examinations have been carried out to find the physiological background of the opening and c losing of the neoglottis. In this paper, we present our findings of the ope ning and closing mechanism of the neoglottis and discuss them with reviewin g the previous studies. Subjects and methods: Subjects were volunteer esophageal speakers. Neoglott al width, EMG of the inferior pharyngeal constrictor (IPC) and that of the geniohyoid muscle (GH) were recorded simultaneously during swallowing and a ir intake for esophageal speech. Results: At rest, the neoglottis was closed by the mucosal protrusion in th e posterior wall of the pharyngoesophagus. During swallowing, the neoglotti s was widely opened. Traction of the anterior pharyngeal wall anteriorly by the GH and reciprocal suppression of the IPC activity was thought to be th e mechanism of the neoglottal opening in this case. However, such simple re ciprocity was not observed during air intake, although transient opening of the neoglottis was commonly observed. The GH showed increased activity at neoglottal opening as it did during swallowing. The IPC was, on the other h and, continuously activated, and no significant suppression was observed. D uring air intake, the muscle is assumed to play a role in maintaining the s hape and tension of the posterior mucosal protrusion which acts as a voice source in subsequent phonation. Conclusions: The GH and the IPC were found to open and close the neoglottis , respectively. Their activities were not always clearly reciprocal in the various functions of the neoglottis. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.