甲状軟骨形成不全の１症例

Abstract

A mutational voice disorder was treated with Thyroplasty Type III. A 29-year-old male, whose chief complaint was his inability to lower his vocal pitch, had no laryngeal prominence in the anterior cervical region on inspection, and the angle formed by the lateral plates of the thyroid cartilage was markedly large and the plates themselves were palpated flat, thin and soft. Image diagnosis also showed an abnormally shaped thyroid cartilage. The mutational voice disorder was thought to be due to this abnormally shaped thyroid cartilage.Voice therapy was initiated to lower the patient's speaking pitch range of 285Hz, which is equivalent to female pitch, but was ineffective. Thyroplasty Type III was performed and the voice immediately fell to 139Hz.There have been many reports regarding congenital malformations of the larynx. However, the malformation in this case was unnoticed until after puberty in the form of a mutational voice disorder since no other disturbance such as dyspnea or hoarseness, which usually accompany an abnormally shaped thyroid cartilage, had occurred.