ABSTRACT
Tracheal intubation for general anesthesia is usually performed using a rigid laryngoscope and reguires the mandible to be opened with forward and upward traction of the patient's jaw which may at times result in the inadvertant injury to temporomandibular joint(TMJ). The injury may include internal derangement, dislocation and hematoma of TMJ; subsequent intraarticular adhesion formation ; dislocation of the meniscus, and rarely auriculotemporal nerve damage from traumatic TMJ dislocation. We studied in 200 patients the size of mouth opening during intubation, the change of mouth opening by tracheal intubation evaluated after operation, and any TMJ disorder arising after tracheal intubation. The results were as follows; 1) The mean size of mouth opening before operation was 42.7+/-7.0 and 40.6+/-6.2mm in male and female patients, respectively. 2) The mean size of mouth opening during intubation was 24.7+/-2.6 and 23.4+/-2.7mm in male and female patients, respectively. When vecuronium was used to prevent fasciculation, the mean was 24.3+/-3.1 and 25.2+/-2.0mm in male and female patients, respectively. 3) One week following operation The mean size of mouth opening one week postoperation was 48.3+/-8.9 and 42.2+/-6.3mm in male and female patients, respectively. When vecuronium was used to prevent fasciculation, the mean size of mouth opening was 55.5+/-5.3 and 43.2+/-6.2mm in male and female patients, respectively. 4) Five patients complained of discomfort around TMJ after tracheal intubation. It seems that upward 45 mandibule lifting by laryngoscope caused trauma to TMJs.