Much oral surgery (for instance, the removal of unerupted or partly erupted mandibular third molars) requires the removal of substantial amounts of mandibular bone. This can cause severe postoperative pain accompanied by oedema, so postoperative analgesia is needed routinely.
Analgesia can be provided by opiates, paracetamol or aspirin, or long duration local anaesthetics.
The most frequently used postoperative analgesic is a combination of codeine phosphate 30 mg with paracetamol 500 mg. For severe pain, an adult dose of two tablets, repeated after 4 hours, or for some younger adults, one tablet repeated after 3 hours, as needed, is usually adequate for pain control. The combination of codeine and paracetamol is available as a pharmaceutical benefit. To minimise wastage, it may be appropriate to prescribe only 10 tablets rather than the permitted maximum quantity of 20 tablets.
Nonsteroidal anti inflammatory drugs (NSAIDs) are effective in controlling postoperative pain from oral surgery, including most third molar surgery. These drugs can be given regularly if pain is anticipated as they appear to prevent dental pain more effectively than they provide analgesia for established pain. When taken regularly for 4-6 days, NSAIDs effectively control most pain arising from oral surgery. Used regularly instead of on demand, they substantially reduce the need for opiates following oral surgery.
Preemptive use of NSAIDs is gaining popularity before third molar surgery. Generally, a preoperative dose of, for instance, naproxen 500 mg approximately one hour before surgery is effective. The same drug can be continued postoperatively e.g. naproxen 250 mg 2-3 times daily.
Extended-duration local anaesthetics can control pain in the immediate postoperative period when it is likely to be more intense. Mandibular regional block anaesthesia is relatively easily accomplished and a dose of bupivacaine 4.4 mL of 0.5% with 1:200 000 adrenaline for each block injection will provide analgesia for 6-8 hours. A similar dose of bupivacaine as a maxillary block injection is also effective. Local infiltration of bupivacaine appears slightly less effective for postoperative pain relief.