Temporomandibular joint dysfunction following the use of a supraglottic airway device during general anaesthesia: a prospective observational study.

Supraglottic airway devices are commonly used to manage the airway during general anaesthesia. There are sporadic case reports of temporomandibular joint dysfunction and dislocation following supraglottic airway device use. We conducted a prospective observational study of adult patients undergoing elective surgery where a supraglottic airway device was used as the primary airway device. Pre-operatively, all participants were asked to complete a questionnaire involving 12 points adapted from the Temporomandibular Joint Scale and the Liverpool Oral Rehabilitation Questionnaire. Objective measurements included inter-incisor distance as well as forward and lateral jaw movements. The primary outcome was the inter-incisor distance, an accepted measure of temporomandibular joint mobility. Both the questionnaire and measurements were repeated in the postoperative period and we analysed data from 130 participants. Mean (SD) inter-incisor distance in the pre- and postoperative period was 46.5 (7.2) mm and 46.3 (7.5) mm, respectively (p = 0.521) with a difference (95%CI) of 0.2 (-0.5 to 0.9) mm. Mean (SD) forward jaw movement in the pre- and postoperative period was 3.6 (2.4) mm and 3.9 (2.4) mm, respectively (p = 0.018). Mean (SD) lateral jaw movement to the right in the pre- and postoperative period was 8.9 (4.1) mm and 9.1 (4.0) mm, respectively (p = 0.314). Mean (SD) lateral jaw movement to the left in the pre- and postoperative period was 8.8 (4.0) mm and 9.3 (3.6) mm, respectively (p = 0.008). The number of patients who reported jaw clicks or pops before opening their mouth as wide as possible was 28 (21.5%) vs. 12 (9.2%) in the pre- and postoperative period, respectively (p < 0.001) with a difference (95%CI) of 12.3% (6.7-17.9%). There was no significant difference in the responses to the other 11 questions or in the number of patients who reported pain in the temporomandibular joint area postoperatively. No clinically significant dysfunction of the temporomandibular joint following the use of supraglottic airway devices in the postoperative period was identified by either patient questionnaires or objective measurements