Bite blocks are essential during anesthesia and surgical procedures, especially those involving endotracheal intubation or transcranial motor-evoked potential (TcMEP) monitoring. They primarily prevent dental trauma, tongue lacerations, and damage to endotracheal tubes caused by patients biting down inadvertently during recovery from anesthesia or under intraoperative neuromonitoring. Using bite blocks is not just a precaution—it is often a necessary safety measure, especially in neurosurgical and spine procedures where TcMEP is used, as these electrical stimulations can trigger strong, involuntary jaw contractions (1).

To maximize efficacy and patient safety, specific techniques are required for the design and placement of bite blocks. Ideally, a bite block is positioned between the molars rather than the incisors to prevent anterior tooth fracture and allow better occlusal force distribution. Bite blocks are manufactured from various materials, including rubber, plastic, and specialized foam. Newer designs incorporate integrated oxygen delivery systems or airways to maintain patency and oxygenation (2). Reusability and biocompatibility are key considerations, especially in prolonged procedures or situations requiring repeated usage.

Although bite blocks can significantly reduce the incidence of orofacial injury and are widely used during anesthesia, complications may arise if they are used improperly. Yan et al. reported cases of airway trauma resulting from incorrectly placed or poorly secured bite blocks, emphasizing the importance of precise technique (3). Whenever feasible, the insertion process must be performed carefully under direct visualization, and compatibility with existing airway devices must be ensured. Additionally, anesthesiologists must be aware of the risk of pressure necrosis if a bite block is left in place for an extended period without intermittent repositioning or examination.

TcMEP monitoring, which is becoming the standard in spinal and brain surgeries, presents a unique challenge in this context. The forceful jaw clenching associated with this monitoring has led to reports of tongue, lip, and dental injuries despite the presence of bite blocks. Kawamoto et al. introduced a novel mouthpiece design to mitigate such injuries. Their design emphasizes a larger surface area and a tailored fit to reduce slippage and provide more even force dispersion (4). A study demonstrated a significant reduction in soft tissue injuries during TcMEP procedures, validating the necessity of evolving equipment alongside advancing surgical techniques.

Furthermore, clinical evidence highlights the importance of preventive strategies. Rice et al. conducted a retrospective analysis of patients undergoing TcMEP monitoring and reported that bite injuries occurred in up to 6.5% of cases where standard precautions were not taken (5). This highlights that bite blocks alone are not sufficient; without proper positioning and continuous monitoring, their protective benefits may be significantly reduced. Awareness campaigns and institutional protocols, including staff education on bite block application and monitoring, are therefore integral to enhancing patient safety.

While innovations continue, the importance of clinician vigilance, proper technique, and choosing the appropriate device for the patient’s anatomy and procedure type cannot be overstated. A well-positioned bite block not only safeguards patient welfare but also protects the integrity of surgical and anesthetic interventions. Given the increasing use of intraoperative neuromonitoring and prolonged sedation techniques, the role of bite blocks in modern anesthesia practice is expected to grow, necessitating ongoing research and refinement in their design and application.

References

1. Bhamri S, Dey S, Gupta M, Bindu B, Arora M. Intraoperative Dental Injury in a Neurosurgical Patient: Concerns for the Anesthesiologist. Cureus. 2022;14(11):e31268. Published 2022 Nov 8. doi:10.7759/cureus.31268
2. Teng WN, Ting CK, Wang YT, et al. Novel mandibular advancement bite block with supplemental oxygen to both nasal and oral cavity improves oxygenation during esophagogastroduodenoscopy: a bench comparison. J Clin Monit Comput. 2019;33(3):523-530. doi:10.1007/s10877-018-0173-9
3. Yan Z, Tanner JW, Lin D, et al. Airway trauma in a high patient volume academic cardiac electrophysiology laboratory center. Anesth Analg. 2013;116(1):112-117. doi:10.1213/ANE.0b013e31826f9125
4. Oshita K, Saeki N, Kubo T, Abekura H, Tanaka N, Kawamoto M. A novel mouthpiece prevents bite injuries caused by intraoperative transcranial electric motor-evoked potential monitoring. J Anesth. 2016;30(5):850-854. doi:10.1007/s00540-016-2220-3
5. Tamkus A, Rice K. The incidence of bite injuries associated with transcranial motor-evoked potential monitoring. Anesth Analg. 2012;115(3):663-667. doi:10.1213/ANE.0b013e3182542331