Fields of treatments Total number of patients Incidence of arytenoid Gastrointestinal surgery 1809 2 Orthopedics 1670 0 Otorhinolaryngology, head and neck surgery 1309 0 Obstetrics and gynecology 967 0 Maxillo-facial and reconstructive surgery 760 0 Cardiovascular surgery 667 12 Neurosugery 660 1 Urology and adrenal gland surgery 559 0 Ophthalmology 361 0 Respiratory surgery 362 3 Breast surgery 196 0 Others 374 2 Total number 9694 20

Table 1: The list of total patients treated or examined under general anesthesia with tracheal intubation and the incidence of patients with arytenoid cartilage dislocation in the Central Surgical Center of Nippon Medical School Main Hospital for two years from 2004 to 2005.