[A case of trismus at anesthesia induction possibly attributable to traumatic cervical syndrome]

We recently had a 41-year-old male who developed trisms at anesthesia induction, probably due to traumatic cervical syndrome. Preoperatively, this patient had been able to open his mouth sufficiently to an extent of at least three finger breadths in width. However, when anesthesia was induced, his mouth could be manually opened only to an extent of about one finger breadth in width. As a result, intubation was difficult. As the trismus did not respond to a muscle relaxant, we were forced to use the Airwayscope for intubation. When the patient awoke from anesthesia, he was again capable of spontaneously opening his mouth to the three-finger breadth extent recorded before surgery. MRI revealed no abnormalities and the patient was diagnosed as having temporomandibular arthrosis based on clinical signs. Regarding the relationship between traumatic cervical syndrome and trismus due to temporomandibular arthrosis, while reports began to be published overseas in the 1990s, few such reports are yet available in Japan. Under the recent trend of increased day surgery, assessments made before surgery tend to be confined to routinely adopted items. Considering that even mild trauma after a car accident triggers temporomandibular arthrosis, the author proposes that preoperative examinations should include checking for a history of traumatic cervical syndrome within one year. Furthermore, the anesthetist should keep in mind the possibility of difficulty with intubation and be prepared to take appropriate measures immediately.