音声障害の臨床研究の４８年を省みて

Abstract

Reviewing the author's 48year experiences of experimental as well as clinical investigation into voice disorders, he describes here their extracts that appear to have particular clinical implication. The topic of initial study was the control mechanism of vocal intensity and pitch. In the process of animal experiment, the author had been intrigued by the reflex that increased subglottal pressure induces glottal closure. This needs to be further studied in connection with mis-swallowing (dysphagia) for instance. The experiments with the excised larynx has later hinted and led to the development of arytenoid adduction technique for vocal fold paralysis, and the surgery for spasmodic dysphonia i.e. type 2 thyroplasty.The two main causes for hoarseness are imperfect closure of the glottis and stiff vocal fold or reduced mobility of the mucosa. In this connection the author emphasizes that any medialization procedure for imperfect closure of the glottis would not restore a good voice unless vocal fold mucosa is well mobile. Chordal injection of autologous tissue such as fat or fascia for augmentation or medialization also requires caution not to expand the overlying mucous membrane in excess or not to create wide scar adhesion between the mucosa and transplanted tissue.The tips of various thyroplasties and arytenoid adduction have briefly been described. As to the future tasks and prospect of voice research, the author stresses the need of biosyntheses or regeneration, using bioengineering technique, of the vocal folds such that covered with a well mobile mucosa. Clinically phonosurgery should steadily extend its indication, based on stable outcomes, not only to inveterate laryngeal diseases but also to aged voice or professional singers' problem for instance. The prospect of further development seems promising for the future.