O. Ross Beirne

Laryngeal Mask Airways Have a Lower Risk of Airway Complications Compared With Endotracheal Intubation: A Systematic Review

PURPOSE The purpose of the present study was to determine whether, in patients undergoing general anesthesia, those provided with a laryngeal mask airway (LMA) have a lower risk of airway-related complications than those undergoing endotracheal intubation. MATERIALS AND METHODS A systematic review of randomized prospective controlled trials was done to compare the risk of airway complications with an LMA versus an endotracheal tube (ETT) in patients receiving general anesthesia. Two independent reviewers identified 29 randomized prospective controlled trials that met the predetermined inclusion and exclusion criteria. The data for each individual outcome measure were combined to analyze the relative risk ratios (RRs). The Cochrane RevMan software was used for statistical analysis. RESULTS When an ETT was used to protect the airway, a statistically significant greater incidence of hoarse voice (RR 2.59, 95% confidence interval [CI] 1.55 to 4.34), a greater incidence of laryngospasm during emergence (RR 3.16, 95% CI 1.38 to 7.21), a greater incidence of coughing (RR 7.12, 95% CI 4.28 to 11.84), and a greater incidence of sore throat (RR 1.67, 95% CI 1.33 to 2.11) was found compared with when an LMA was used to protect the airway. The differences in the risk of regurgitation (RR 0.84, 95% CI 0.27 to 2.59), vomiting (RR 1.56, 95% CI 0.74 to 3.26), nausea (RR 1.59, 95% CI 0.91 to 2.78), and the success of insertion on the first attempt (RR 1.08, 95% CI 0.99 to 1.18) were not statistically significant between the 2 groups. CONCLUSIONS For the patients receiving general anesthesia, the use of the LMA resulted in a statistically and clinically significant lower incidence of laryngospasm during emergence, postoperative hoarse voice, and coughing than when using an ETT. The risk of aspiration could not be determined because only 1 study reported a single case of aspiration, which was in the group using the ETT.

Off-label use of recombinant human bone morphogenetic protein-2 (rhBMP-2) for reconstruction of mandibular bone defects in humans.

PURPOSE The off-label use of recombinant human bone morphogenetic protein-2 (rhBMP-2) for the treatment of mandibular bone defects was evaluated in 5 patients. The rhBMP-2 was used as an alternative to autogenous bone grafting. PATIENTS AND METHODS A total of 5 patients had mandibular defects reconstructed with rhBMP-2, 1.5 mg/mL, soaked collagen sponges alone or in combination with bone marrow cells and allogenic cancellous bone chips. Four of the patients had mandibular continuity defects and the fifth patient had 2 large bone cavities following removal of dentigerous cysts. Radiographs and clinical examinations were used to evaluate healing. The longest patient follow-up was 22 months after reconstruction. RESULTS Radiographic and clinical assessments revealed bone regeneration and restoration of the mandibular defects in 3 of the 5 patients. The rhBMP-2 failed in 2 patients with continuity defects. Both patients with failed rhBMP-2 grafts were successfully repaired using autogenous harvested from the iliac crest. CONCLUSION Mandibular bone defects can be successfully reconstructed using rhBMP-2 soaked sponges with and without including bone marrow cells and allogenic bone. Further studies are needed to determine the ideal combination of components that will predictably and reliably regenerate bone in different types of bone defects.

Surgical Management of Patients on Warfarin Sodium

PURPOSE Management of anticoagulated patients has changed significantly over the past 10 years. The change occurred after the introduction of the international normalized ratio (INR) in 1983. This method of reporting prothrombin time for anticoagulated patients has resulted in a decrease in the level at which hematologists and cardiologists keep their patients anticoagulated. Currently, patients are anticoagulated less for the successful prevention of thromboemboli. Recent recommendations are to keep patients anticoagulated to an INR no greater than 3.5. It has been proposed that the extraction of teeth can be performed with INRs of 4 or less. Therefore, the current trend is to maintain patients on their anticoagulation regimens without altering their warfarin dosages. CONCLUSION With proper local measures, teeth can be extracted safely and the development of thromboemboli in high-risk patients can still be prevented. However, with procedures having a high risk of bleeding, warfarin dosage may need to be modified.

The relationship of denosumab pharmacology and osteonecrosis of the jaws

Denosumab is a new bone antiresorptive agent that has received approval by the Food and Drug Administration for use in patients with osteoporosis and metastatic cancer to the bones. Like the bisphosponates that are used as antiresorptive medications, denosumab has been associated with osteonecrosis of the jaws (ONJ). However, because the pharmacodynamics and pharmacokinetics of denosumab differ from that of the bisphosphonates, ONJ related to denosumab may resolve more rapidly with a drug holiday than bisphosphonate-related osteonecrosis of the jaws (BRONJ). This paper describes the management of a patient who developed ONJ while receiving denosumab, reviews the incidence of ONJ associated with denosumab, and compares the pharmacology of denosumab and the bisphosphonates. Because the effects of denosumab on bone turnover are more rapidly reversible than the effects of the bisphosphonates, ONJ related to denosumab may resolve more quickly with a drug holiday than BRONJ.

Effect of hydroxylapatite, tricalcium phosphate, and collagen on the healing of defects in the rat mandible☆

The effects of hydroxylapatite and tricalcium phosphate alone or mixed with collagen on the repair of surgically created bony defects in the mandible of 30 rats were evaluated by gross examination and light microscopy. When specimens were examined 4 and 12 weeks after placement of the implants, bone was observed in direct contact with the implants at the periphery; however, in the central portion of the defects, the implants were surrounded by fibrous connective tissue containing macrophages and a few multinucleated giant cells. Neither the hydroxylapatite or the tricalcium phosphate induced bony healing in the defect, and the addition of collagen did not interfere with healing. Because collagen does not alter healing, it might be possible to use it as biocompatible resorbable binder to confine particulate ceramic implants and inhibit their migration.

The anxiolytic effects of intravenous sedation using midazolam alone or in multiple drug techniques

This study examines four drug combinations (midazolam, midazolam-midazolam, fentanyl-midazolam, and fentanyl-midazolam-methohexital) in a placebo-controlled double-blind clinical trial of intravenous sedation. It tests the hypothesis that there is no difference between the anxiolytic effect of the four combinations when compared with a saline placebo. Subjects were 207 mildly anxious young adults having their third molars removed. Cognitive measures of anxiety increased from preoperative levels in the placebo and both midazolam groups (P < .05). The anxiety response remained the same in the fentanyl-midazolam and fentanyl-midazolam-methohexital groups (P > .05). The level of successful anxiolysis ranged from 24% in the placebo group to 74% in the barbiturate group. Using the log likelihood method, comparisons suggest that the drug groups (from midazolam alone to the methohexital combination) have increasingly positive anxiolytic effects even when controlling for the effects of dental fear and intraoperative pain. The fentanyl-midazolam group is 8.1 and the methohexital group is 9.0 times more likely to have had a favorable outcome than the placebo group. Additional analyses of behavioral measures of anxiety yielded parallel results. Global evaluations after surgery were related to the success of anxiolysis for subjects in the active drug conditions (P < .05).

Long-standing mandibular dislocation: Report of a case

This report describes a rare case of long-standing mandibular dislocation and its treatment by condylectomy, coronoidectomy, and suprahyoid myotomy.

Concepts in the prevention and management of malignant hyperthermia.

Malignant hyperthermia (MH) is a potentially lifethreatening hypermetabolic condition that is triggered in susceptible individuals by several inhalation anesthetic agents and/or succinylcholine. The triggering agents reduce the uptake of calcium from the sarcoplasmic reticulum of skeletal muscle in susceptible patients. The increased cytoplasmic calcium sustains uncontrolled contraction in the skeletal muscles, resulting in the symptoms of MH. 1 MH is inherited as an autosomal dominant disorder, and most susceptible individuals are asymptomatic until they are exposed to a triggering agent. When exposed to a triggering agent, tachycardia, hypercapnia, tachypnea, hyperthermia, hypermetabolism, acidemia, cardiac dysrhythmias, hypercalcemia, hyperkalemia, elevated creatinine kinase (CK) and transaminases, skin mottling, and muscle rigidity may become evident. If untreated, mortality approaches 70%. 2 Oral and maxillofacial surgeons who use triggering agents like succinylcholine in their offices must be able to recognize and treat MH. Lack of specific symptoms can make the diagnosis of MH difficult. 2,3 Some regard elevated temperature as a hallmark feature of MH; however, temperature rises late in the course of MH. Frequent and early symptoms of MH include tachycardia, supraventricular or ventricular dysrhythmias, and cardiac arrest. A sensitive early finding is a rapid increase in end-expiratory carbon dioxide concentration. 3 Many regard masseter muscle spasm (“trismus”) as an early sign of an MH crisis. However, succinylcholine can induce masseter muscle spasm without triggering MH. Approximately 50% of patients with masseter muscle spasm are prone to MH. 2,4 As routine oral and maxillofacial surgery procedures move from the hospital to outpatient facilities where triggering agents are commonly used, the oral and maxillofacial surgeon must be aware of the signs, symptoms, and management of MH. The purpose of this article is to review the triggering agents, the incidence of occurrence, and the management of MH and to discuss the role of dantrolene in managing MH crisis. The need to stock dantrolene in the offices of oral and maxillofacial surgeons is also reviewed.

What is the Risk of Future Extraction of Asymptomatic Third Molars? A Systematic Review

PURPOSE The purpose of our report was to determine clinically whether young adults who elect to retain their asymptomatic third molars (M3s) have a risk of undergoing 1 or more M3 extractions in the future. MATERIALS AND METHODS To address our clinical question, we designed and implemented a systematic review. The studies included in the present review were prospective, had a sample size of 50 subjects or more with at least 1 asymptomatic M3, and had at least 12 months of follow-up data available. The primary study variables were the follow-up duration (in years) and the number of M3s extracted by the end of the follow-up period or the number of subjects who required at least one M3 extraction. The annual and cumulative incidence rates of M3 removal were estimated. RESULTS Seven studies met the inclusion criteria. The samples sizes ranged from 70 to 821 subjects, and the follow-up period ranged from 1 to 18 years. The mean incidence rate for M3 extraction of previously asymptomatic M3s was 3.0% annually (range 1 to 9%). The cumulative incidence rate for M3 removal ranged from 5% at 1 year to 64% at 18 years. The reasons for extraction were caries, periodontal disease, and other inflammatory conditions. CONCLUSIONS The cumulative risk of M3 extraction for young adults with asymptomatic M3s is sufficiently high to warrant its consideration when reviewing the risks and benefits of M3 retention as a management strategy.

Autogenous bone grafts for atrophic edentulous mandibles: A final report

While autogenous bone augmentations for atrophic edentulous mandibles are not the ideal solution for this problem, we do not share the pessimism of other investigators. The average loss of bone over the 92-month observation period was 60% for this small sample of eight patients. However, there was an 81% gain in bone height in the premolar-molar regions when compared with presurgical measurements. Seven of the eight patients believed these procedures were beneficial.