Effects of Local Ketamine in Orthognathic Procedures

Overview

Orthognathic surgery is performed to correct congenital, developmental, or trauma-related skeletal deformities of the maxilla and mandible. These procedures involve multiple incisions, dissections, and osteotomies, leading to significant postoperative inflammatory responses and acute pain. Postoperative pain is a key factor influencing recovery, return to function, and length of hospital stay. Various analgesics have been used to manage pain after orthognathic surgery, including NSAIDs, opioids, acetaminophen, NMDA receptor antagonists, and long-acting local anesthetics. Ketamine is a well-known NMDA receptor antagonist with both central and peripheral analgesic effects. In subnesthetic doses, ketamine has been evaluated in various surgical fields for its potential to enhance analgesia when combined with local anesthetics, while minimizing systemic side effects. Studies have shown that local ketamine administration during cleft palate repair and third molar extractions can significantly reduce postoperative pain, swelling, and trismus. However, to date, no studies have investigated the effects of locally administered ketamine in orthognathic surgery. Therefore, this study was designed to evaluate the intraoperative and postoperative effects of local ketamine injection in this context.

Orthognathic surgery is performed to correct congenital or developmental anomalies of the maxilla and mandible, as well as secondary deformities caused by trauma. These procedures require multiple incisions, dissections, and osteotomies in both the maxilla and mandible. The acute postoperative pain that follows orthognathic surgery is primarily the result of these surgical traumas and the subsequent inflammatory process. As tissue healing progresses, postoperative pain gradually subsides. This type of pain is one of the primary factors affecting postoperative recovery, return to function, and length of hospital stay. Many studies have focused on achieving optimal analgesia during this period, which significantly affects patients' postoperative quality of life. For this purpose, several agents have been used, including non-steroidal anti-inflammatory drugs (NSAIDs), opioids, non-opioid analgesics (such as acetaminophen), NMDA receptor antagonists, and long-acting local anesthetics. Ketamine is a well-known general anesthetic and short-acting intraoperative analgesic agent with established pharmacodynamic and pharmacokinetic profiles and known side effects. Ketamine is a non-selective antagonist of supraspinal N-methyl-D-aspartate (NMDA) receptors. It is believed that inhibition of these receptors reduces neuronal excitation and produces analgesia through this mechanism. Ketamine's interactions with spinal pain receptors and opioid receptors are also thought to contribute to its analgesic effects. In low doses, ketamine has been evaluated for local analgesic purposes in combination with local anesthetics in various surgical procedures, aiming to minimize side effects. Cleft palate repair and third molar extractions are among the oral surgery procedures where the local analgesic efficacy of ketamine has been investigated. In a study by Jha et al. on cleft palate repair, the authors examined the effects of local bupivacaine combined with ketamine on postoperative nausea, vomiting, dysphagia, and sleep patterns. They found that patients in the ketamine group had superior outcomes in terms of reduced need for additional analgesia, improved sleep, and earlier return to feeding. Similarly, in the literature some studies reported that significant reductions in postoperative pain, swelling, and trismus in third molar extraction patients when sub-anesthetic doses of ketamine were combined with local anesthetics. Shah et al. also observed that combining ketamine with local anesthetics during third molar extraction reduced postoperative pain and swelling compared to local anesthetics alone. To date, there are no studies in the literature investigating the effects of combining ketamine with local anesthetics in orthognathic surgery. Therefore, this study was designed to address this gap.