Introduction

The removal of third molar teeth is one of the most common procedures performed by oral and maxillofacial surgeons. Third molar extraction is associated with undesirable sequelae and complication. Morbidity is related to pain, swelling, trismus, infection, alveolar osteitis, bleeding, nerve injury, dental injury, jaw fracture, temporomandibular joint dysfunction, lost workdays, and general inconvenience. Many factors and strategies have been studied to minimize the morbidity associated with third molar removal. This article focuses on perioperative strategies that have been suggested to influence the postoperative course after third molar extraction. These include the effect of smoking, chlorhexidine rinses, topical and systemic antibiotic use, and preemptive pharmacotherapies, including corticosteroids, analgesics, and muscle relaxants. Additional factors that may play a role, such as microbial contamination, surgical difficulty, surgeon experience, flap design, extent and closure, presurgical pathology, age, gender, and oral contraceptive use, are not addressed.

Tobacco smoking

The influence of smoking on postsurgical complications is well appreciated. The direct and indirect effects of cigarette smoke have been well described in relation to multiple soft tissue reconstructive procedures, including facelifts, abdominoplasty, breast reconstruction, free tissue transfer, and digit replantation ( Table 1 ) . The dental literature has also shown the detrimental effects of tobacco smoking on the immune response, alveolar bone loss, oral wound healing, and response to therapy ( Table 2 ) . Additionally, a recent systematic review showed that longer durations of perioperative smoking cessation seem to be beneficial, but the ideal period of tobacco cessation could not be specified. Outcome variables such as overall postoperative complications, mortality, pulmonary and respiratory complications, and wound infections were examined. A variety of general surgery procedures and onlay bone grafts and sinus lifts were evaluated, but dental extractions were not reviewed.

The literature relating smoking and third molar extraction is minimal. Al-Belasy investigated the effect of smoking on incidence dry socket after mandibular third molar removal in men, comparing nonsmokers with cigarette and “shisha” smokers. They showed an incidence of 7% in nonsmokers, 31.6% in smokers who refrained the day of surgery, 17.9% in smokers who ceased tobacco use until the second day after surgery, and 10.5% when tobacco cessation continued until the third postoperative day or longer. A statistically significant difference was found between smokers and nonsmokers, but the difference between cigarette and shisha smokers was not found to be statistically significant. Further discussion provides support against the influence of the negative pressure effect of smoking on clot dislodgement and subsequent dry socket, favoring a systemic and local tissue pathogenesis. This finding agrees with the research of Meechan and colleagues , who showed significant differences in immediate socket filling and postoperative pain in smokers over nonsmokers, especially female heavy smokers. Conversely, reports have shown no significant difference between smokers and nonsmokers in postoperative pain and wound healing.

Additional dental research evaluating periodontal regenerative therapy with an allograft has shown significant differences between smokers and nonsmokers. Rosen and colleagues found that smokers had a 29% improvement in clinical attachment level, whereas nonsmokers had a 42% improvement at 1-year follow-up. This trend persisted long-term, with improvement of 31% and 42% for smokers and nonsmokers at 2 to 5 years, respectively. The adverse effects of tobacco smoking should encourage perioperative tobacco cessation. Grossi and colleagues showed that tobacco cessation improved their patient population’s healing response to equate that of nonsmokers, with similar observations on periodontal microbial content. The systemic and local influences of tobacco use are well-known. However, the relationship of smoking and postoperative course in relation to third molar surgery is not completely understood and has not been clearly proven to be causal in nature. Further studies are necessary to elucidate the mechanisms that make smoking a significant risk factor for dry socket. Preoperative and a minimum of two postoperative days of tobacco cessation is recommended for third molar dry socket prevention.

Tobacco smoking

The influence of smoking on postsurgical complications is well appreciated. The direct and indirect effects of cigarette smoke have been well described in relation to multiple soft tissue reconstructive procedures, including facelifts, abdominoplasty, breast reconstruction, free tissue transfer, and digit replantation ( Table 1 ) . The dental literature has also shown the detrimental effects of tobacco smoking on the immune response, alveolar bone loss, oral wound healing, and response to therapy ( Table 2 ) . Additionally, a recent systematic review showed that longer durations of perioperative smoking cessation seem to be beneficial, but the ideal period of tobacco cessation could not be specified. Outcome variables such as overall postoperative complications, mortality, pulmonary and respiratory complications, and wound infections were examined. A variety of general surgery procedures and onlay bone grafts and sinus lifts were evaluated, but dental extractions were not reviewed.

The literature relating smoking and third molar extraction is minimal. Al-Belasy investigated the effect of smoking on incidence dry socket after mandibular third molar removal in men, comparing nonsmokers with cigarette and “shisha” smokers. They showed an incidence of 7% in nonsmokers, 31.6% in smokers who refrained the day of surgery, 17.9% in smokers who ceased tobacco use until the second day after surgery, and 10.5% when tobacco cessation continued until the third postoperative day or longer. A statistically significant difference was found between smokers and nonsmokers, but the difference between cigarette and shisha smokers was not found to be statistically significant. Further discussion provides support against the influence of the negative pressure effect of smoking on clot dislodgement and subsequent dry socket, favoring a systemic and local tissue pathogenesis. This finding agrees with the research of Meechan and colleagues , who showed significant differences in immediate socket filling and postoperative pain in smokers over nonsmokers, especially female heavy smokers. Conversely, reports have shown no significant difference between smokers and nonsmokers in postoperative pain and wound healing.

Additional dental research evaluating periodontal regenerative therapy with an allograft has shown significant differences between smokers and nonsmokers. Rosen and colleagues found that smokers had a 29% improvement in clinical attachment level, whereas nonsmokers had a 42% improvement at 1-year follow-up. This trend persisted long-term, with improvement of 31% and 42% for smokers and nonsmokers at 2 to 5 years, respectively. The adverse effects of tobacco smoking should encourage perioperative tobacco cessation. Grossi and colleagues showed that tobacco cessation improved their patient population’s healing response to equate that of nonsmokers, with similar observations on periodontal microbial content. The systemic and local influences of tobacco use are well-known. However, the relationship of smoking and postoperative course in relation to third molar surgery is not completely understood and has not been clearly proven to be causal in nature. Further studies are necessary to elucidate the mechanisms that make smoking a significant risk factor for dry socket. Preoperative and a minimum of two postoperative days of tobacco cessation is recommended for third molar dry socket prevention.

Chlorhexidine

Chlorhexidine digluconate (CHX) is a commonly used topical antimicrobial agent used in dentistry. It has been shown to be effective in treatment and maintenance for periodontal disease and caries. CHX acts on gram-positive and gram-negative aerobes and anaerobes through membrane disruption. The therapeutic action of CHX is further enhanced by its substantivity, the ability to have a continued effect between dosages. Resistance and pathogen selection have not been shown to occur with use of CHX. Additionally, the adverse effects of CHX are minimal, including allergy, dental staining, increased calculus formation, and mucosal and taste alterations. The role of CHX rinses in prevention of alveolar osteitis (AO) and surgical site infection has also been extensively studied, with evidence for and against its use. The main arguments against CHX use is that a lack of evidence exists to prove its efficacy, failing to justify the associated expense.

In 1991, Larsen performed a prospective, randomized, double-blind, placebo-controlled trial showing a 60% overall reduction of AO with the use of 0.12% CHX 1 week before and after M3 removal. This trial was based on a microbiologic explanation of the fibrinolysis related to AO. In 2005, in a meta-analysis review of human clinical trials involving mandibular third molar extractions only, Caso and colleagues compared a preoperative rinse, preoperative and postoperative rinsing regimen, and control groups. The results showed that the benefit of CHX on the day of surgery alone did not reach statistical significance. However, they did find that an extended rinse period of several postoperative days may reduce AO incidence. In a similar meta-analysis, Minguez-Sera and colleagues concluded that application of a 0.2% CHX paste every 12 hours for a week after mandibular third molar extraction reduced AO incidence. Overall, the studies investigating the efficacy of CHX in reducing third molar extraction postoperative pain and infection have mixed designs and possible cofounders. However, strong support exists for the use of chlorhexidine rinse and intraalveolar application. Currently, the use of chlorhexidine should be considered in the context of a cost-benefit analysis, and directed by clinical judgment.

Preemptive analgesia

Much of the undesirable nature of third molar surgery is based on patient discomfort and decreased quality of life. Palliation through pharmacologic agents can significantly improve a patient’s condition after surgery. Additionally, a proactive strategy to reduce the amount of discomfort has been investigated. Much of the literature is based on preventative or preemptive analgesia for obstetrics, thoracic surgery, and orthopedics. Evidence in relation to third molar surgery is sparse. Preemptive analgesia, defined as a “pharmacologic intervention initiated before a painful stimulus to inhibit nociceptive mechanisms before they are triggered,” is a common practice. Attributes of an ideal preemptive analgesia regimen include

• 1.

  Initiation before surgical trauma

• 2.

  Prevention of central sensitization secondary to surgical trauma

• 3.

  Prevention of central sensitization secondary to inflammation

• 4.

  Palliation throughout the perioperative period

• 5.

  Therapeutic effect lasting up to or greater than 10 weeks

Local anesthetic medications and nonsteroidal antiinflammatory drugs (NSAIDs) were shown to be more effective than opioids in a meta-analysis by Cliff investigating the influence of preemptive analgesia on acute postoperative pain after major general surgery. A randomized controlled trial by Nayyar and colleagues showed the preemptive effects of bupivacaine 0.5% with epinephrine 1/200,000 to significantly reduce pain at 6, 12, and 72 hours and 7 days. The effects of tramadol and ketoprofen for M3 surgery have been shown to be beneficial, but only data from 24 hours or less are presented, and postoperative dosing may be better for pain intensity, timing of onset, and degree of opioid requirement.

Santos and colleagues investigated the muscle relaxant cyclobenzaprine as a postoperative medicament in a well-designed prospective, randomized, double-blind, placebo controlled, split-mouth study. They concluded that cyclobenzaprine is not useful in treating pain, swelling, or trismus after third molar removal. Currently, local anesthesia is the only pharmacotherapy that has proven efficacy for preemptive analgesia for third molar extractions. The effect of NSAIDs requires greater research to establish longer-term effects and appropriate timing of administration.