Does Surgical Release of TMJ Bony Ankylosis Increase the Risk of Trigeminocardiac Reflex? A Retrospective Cohort Study.

Purpose: The exact frequency of the trigeminocardiac (TGC) reflex in temporomandibular joint (TMJ) surgery is still controversial. The purpose of the present report was to estimate the frequency of and identify the risk factors for TGC reflex among patients undergoing operative management of TMJ ankyloses.

Patients And Methods: A retrospective cohort study was conducted of patients who had undergone gap arthroplasty for TMJ ankyloses at Al-Azhar University Hospital, Cairo, Egypt, from 2001 to 2015. The predictor variables were patient demographic data (age and sex), ankylosis type, and surgery type. The outcome variable was the occurrence of the TGC reflex (yes vs no). The data analysis included descriptive statistics and χ tests to compare the categorical variables. Binary regression logistic model analysis was performed to identify the associated predictor variable. P values were considered statistically significant at ≤ .05.

Results: The sample included 55 subjects. The mean ± standard deviation age of the patients was 21.3 ± 9.855 years, and 43.6% were males. The frequency of TGC reflex was 12.7%. The factors associated with an increased risk of TGC reflex were type IV bony ankylosis (P = .012) and the need for repeat surgery (P = .016.). A multivariable binary regression model analysis demonstrated that the recurrence of surgery was the most significant predictor factor affecting the frequency of the TGC reflex. The computed variance ranged from 13 to 25%. However, other variables, including age, gender, side, and ankylosis type, were not associated with reflex onset (odds ratio, 0.028; 95% confidence interval, 0.001 to 0.911; P = .044).

Conclusions: Recurrent ankylosis surgery carries a high risk of TGC reflex. Preoperative risk factor identification and close monitoring are crucial to prevent the occurrence of this reflex in susceptible patients. Future research projects should include more variables in the study.