The Frequency of Trigeminocardiac Reflex During the Extraction of Impacted Mandibular Wisdom Teeth

The study included 40 patients who underwent extraction of impacted mandibular wisdom teeth.Before the surgical procedure, the two most commonly used local anesthesia techniques in oral surgical practice, GG and IASB techniques, were applied. While IASB was always accompanied by buccal and mylohyoid area supportive anesthesia, no additional anesthesia was required in any patient receiving GG anesthesia. Evaluation of the patients was done using panoramic radiographs. The closest distance between the roots of the relevant wisdom teeth and the inferior alveolar nerve (IAN) was recorded. In cases where the distance was less than 1 mm or where superimposition occurred, cone beam computed tomography (CBCT) images were taken from the patients to confirm the distance in three dimensions.

Patients were divided into two groups based on the proximity of their wisdom tooth roots to the IAN (within 1 mm or more than 1 mm) and into two groups based on the anesthesia technique to be applied (GG-IASB). Subgroups were named as GG-0 (more than 1 mm from IAN), GG-1 (within 1 mm from IAN), IASB-0 (more than 1 mm from IAN), and IASB-1 (within 1 mm from IAN). Ten patients were evenly selected for each subgroup (GG-0, GG-1, IASB-0, IASB-1).

The surgeries included in the study were performed by a single surgeon. Impacted wisdom teeth were vertical and consisted of teeth retained in bone. For the surgical procedure, a sleeve flap was applied including distal horizontal and vertical relaxing incisions near the mesial papilla of mandibular second molar tooth.

TCR monitoring was conducted by observing the occurrence of sudden bradycardia, which could develop within a few seconds and show improvement upon pausing the procedure, not preceded by tachycardia. To ensure accurate and timely monitoring of this sudden process and to monitor potential asystole that could develop, patients were monitored. Monitoring was conducted using 5-channel Contec Medical Systems (Hebei, China) monitors. Throughout the procedure, heart rate, systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure, and oxygen saturation were recorded. Records were taken at six separate surgical stages: initially during local anesthesia administration, and subsequently during incision/flap removal, removal of bone barriers, crown elevation, root elevation, and during suturing. Any sudden changes occurring during the procedure were recorded along with their onset times.

In defining TCR (Trigeminocardiac Reflex) in the literature, various reference measurement methods include sudden drops in heart rate by more than 10%, more than 20%, or dropping below 60 beats per minute. To highlight these different proportional reference drop values, severity grading was used in the observed TCR findings. Sudden drops in heart rate between 10% and 20% were classified as mild TCR (TKR-1), drops exceeding 20% and heart rate falling below 60 bpm as moderate TCR (TKR-2), and the presence of asystole, syncope, or need for atropine application as severe TCR (TKR-3). The total TCR across all grades was termed as t-TCR. TCR calculation was based on heart rate measurements taken at the beginning of each surgical stage.

To exclude vasovagal syncope, commonly cited as a neurological emergency and etiological factor, and high anxiety from the study, patients were initially subjected to anxiety tests, and individuals with high anxiety levels were excluded from the study. Patient anxiety levels were assessed using the Amsterdam Preoperative Anxiety and Information Scale (APAIS) and the State-Trait Anxiety Inventory-State scale (STAI-S).