[Operative field limited by in the case of a tonsillectomy due to temporomandibular arthrosis--a case report].

We report herein on a patient with unexpected trismus after the induction of general anesthesia due to temporomandibular arthrosis. A 30 year old man visited our hospital complaining of hematuria, and he was scheduled for bil tonsillectomy under general anesthesia. Preoperative examination revealed no evidence of difficult airway and no sign of trismus. Despite the administration of muscle relaxants, it was impossible to expand the operative field due to by trismus after the introduction of general anesthesia. Malignant hyperthermia was excluded, and the trismus was judged to be due to temporomandibular arthrosis. Manual repositioning was performed, trismus was improved and expansion of the surgical field became possible. During any head and neck surgical procedure, if an otolaryngologist should encounter trismus after the induction of general anesthesia, temporomandibular arthrosis should be borne in mind if temporomandibular arthrosis is diagnosed as the cause, manual repositioning should be employed as soon as possible.