Adduction-type convulsive dysphonia is a disease in which the glottic closure muscles (vocal cords) inside the larynx inadvertently contract, causing the vocal cords to close inward (inward rotation) during vocalization. Brings difficulties.Botulinum toxin injection is a common treatment, but the effect is on average a few months and requires continuous injection.On the other hand, the "thyroid cartilage plasty type 2" developed in Japan is a titanium hinged plate "thyroid cartilage (larynx cartilage) that is vertically incised and the vocal cords and cartilage attachments are widened outward together with the cartilage. It is said that a semi-permanent effect can be expected with the surgical technique of fixing with "titanium bridge".

　To confirm the effectiveness of this treatment method, a clinical study was conducted at the Department of Otolaryngology, Kumamoto University.Improvement was confirmed in 21 evaluable cases out of 17 target patients.After that, with a subsidy from the Ministry of Health, Labor and Welfare, a multicenter joint doctor-led clinical trial was conducted by the Kumamoto University School of Medicine Hospital.In the clinical trial, a clear improvement in dysphonia was observed in 21 patients during the 52-week observation period, and there were no serious adverse events or defects.

　Titanium bridge is designated as the first item to be examined under the "Prior Examination Designation System" (a system developed for the first time in the world that designates highly effective drugs and aims for early commercialization) as a medical device. After receiving the designation of a medical device for rare diseases, the regulatory approval was obtained by the regulatory application by the company.

　With the acquisition of this regulatory approval, thyroid plasty type 2 surgery using a titanium bridge is expected to be a safe and secure treatment method for patients with adduction-type convulsive dysphonia.