[Voice after supracricoid partial laryngectomy: comparison of two phonatory mechanisms].
INTRODUCTION: Different laryngeal phonatory mechanisms may be observed at long term after supracricoid laryngectomy. For this study two mechanisms are differentiated. The "dilated" mechanism is the consequence of a forward movement of the neolarynx creating a new resonance cavity. The "contracted" mechanism tallies with the backward contraction of the base of the tongue and the contraction of the posterior pharyngeal wall compressing the neolarynx. OBJECTIVE: The aim of the study is to determine if the voice outcome is different between these two kinds of mechanisms. MATERIAL AND METHOD: The method is based on the selection of a homogeneous group: 12 patients operated by cricoepiglottopexy with a follow up superior to two years and with a stable voice and a full neoglottic closure during phonation. The voice quality and the phonatory mechanism are analysed. Regarding voice assessment, a self evaluation with the vocal handicap index adapted for the study and the GRBAS scale are carried-out. Frequency (usual, minimum, maximum, range) and loudness are used to appreciate the vocal capacities. The phonatory mechanism is studied by videolaryngostroboscopy, performed tongue free, with a normal /e/ and a high-low transition pitch. RESULTS: The outcomes point out a difference between the two mechanisms. The best vocal results are observed in the "dilated" mechanism for the studied parameters and mainly for the frequency parameters. CONCLUSION: The discovery of numerous phonatory mechanisms after supracricoid laryngectomy independent from neoglottic closure lead us to further studies of the impact of this type of surgery on articulatory patterns.