Anesthetic considerations and techniques for oral and maxillofacial surgery

The effect of mandibular advancement for mandibular deficiency dentofacial deformities on laryngeal grade and intubation difficulty: a preliminary study

OBJECTIVE

The purpose of this study was to evaluate mandibular advancement for cases of mandibular deficiency with changes in vocal cord grade and intubation difficulty at subsequent surgery requiring intubation.

STUDY DESIGN

This retrospective case series included patients with a diagnosis of mandibular deficiency (Class II skeletal dentofacial deformity) who underwent mandibular advancement surgery (T1) followed by a subsequent surgery (T2) which required intubation. The primary predictor variable was mandibular advancement. The primary outcome variable was the change in laryngeal grade-Cormack and Lehane-after mandibular advancement. A secondary outcome was intubation difficulty after mandibular advancement.

RESULTS

Eight patients were included in the study. At T1, the average laryngeal grade was 1.6. There was 1 difficult intubation. The average time to T2 was 9 months. At T2, all patients were intubated on their first attempt, and all had a Cormack-Lehane Grade I view of the vocal cords. There were no difficult intubations at T2. Analysis showed a significant association between mandibular advancement and laryngeal grade at T2 (P = .03; 95% CI 0.07-1.13).

CONCLUSIONS

This preliminary investigation found an association between mandibular advancement for cases of mandibular and improved laryngeal grade at subsequent intubation without any difficult intubations.

Influence of Lidocaine including Buprenorphine for Postoperative Analgesia after the Extraction of Mandibular Third Molars: A Randomized Controlled, Double-Blind, Split-Mouth Study

Background

The presence of opioid receptors around the peripheral nerves offers the possibility of providing postoperative analgesia, thereby encouraging the study of the effect of opioids in combination with local anesthesia (LA). Studies have also reported the efficacy of peripherally administered opioids in achieving adequate analgesia in regions with inflammation. Applying the concept of peripheral opioid receptors, our study aimed to evaluate the effectiveness of opioid analgesia in managing postoperative pain. The split-mouth study was carried out to evaluate the efficacy of buprenorphine added to lidocaine 2% in providing postoperative analgesia after the surgical extraction of the impacted mandibular third molar.

Materials and Methods

We conducted a randomized, double-blinded, split-mouth trial among 21 patients with impacted mandibular third molars bilaterally. In all patients, bilateral impacted mandibular third molars were extracted at different periods. The primary outcomes assessed were postoperative analgesia by the VAS score and the number of rescue analgesics consumed by patients at 24, 48, and 72 hours of interval via a questionnaire.

Results

There was a statistical significant difference in postoperative analgesia duration at 24 (P = 0.012) and 48 hours (P = 0.024), respectively, between the test and control group. Even though the mean number of rescue analgesics consumed by the test group was less than that of the control group, no significant difference was seen.

Conclusion

Buprenorphine added to lidocaine 2% showed a minimal decrease in the pain score and duration of postoperative analgesia with no difference in the frequency of rescue analgesics consumed between the test and control.

Airway management in maxillofacial trauma

Airway management of patients with maxillofacial trauma remains a challenging task for an anesthesiologist in the emergency and perioperative settings due to anatomical distortion. Detailed knowledge of maxillofacial and airway anatomy is desired for the correct diagnosis of extent and severity of the injury. Basic principles of advanced trauma life support protocols should be followed while managing such patients. Establishing unobstructed airway remains the top priority while maintaining C-spine immobilization and preventing aspiration. Although multiple options exist for securing the airway, a universal technique of airway management may not be applicable to all the patients. Hence, a high index of suspicion along with timely and skillful management is warranted. In this brief review, issues affecting the airway management in cases of maxillofacial trauma are addressed with the possible uses of a wide range of airway management devices available in emergency and elective scenarios.

Effects of airway evaluation parameters on the laryngeal view grade in mandibular prognathism and retrognathism patients

BACKGROUND

Failure to maintain a patent airway can result in brain damage or death. In patients with mandibular prognathism or retrognathism, intubation is generally thought to be difficult. We determined the degree of difficulty of airway management in patients with mandibular deformity using anatomic criteria to define and grade difficulty of endotracheal intubation with direct laryngoscopy.

METHODS

Measurements were performed on 133 patients with prognathism and 33 with retrognathism scheduled for corrective esthetic surgery. A case study was performed on 89 patients with a normal mandible as the control group. In all patients, mouth opening distance (MOD), mandibular depth (MD), mandibular length (ML), mouth opening angle (MOA), neck extension angle (EXT), neck flexion angle (FLX), thyromental distance (TMD), inter-notch distance (IND), thyromental area (TMA), Mallampati grade, and Cormack and Lehane grade were measured.

RESULTS

Cormack and Lehane grade I was observed in 84.2%, grade II in 15.0%, and grade III in 0.8% of mandibular prognathism cases; among retrognathism cases, 45.4% were grade I, 27.3% grade II, and 27.3% grade III; among controls, 65.2% were grade I, 26.9% were grade II, and 7.9% were grade III. MOD, MOA, ML, TMD, and TMA were greater in the prognathism group than in the control and retrognathism groups (P < 0.05). The measurements of ML were shorter in retrognathism than in the control and prognathism groups (P < 0.05).

CONCLUSIONS

Laryngoscopic intubation was easier in patients with prognathism than in those with normal mandibles. However, in retrognathism, the laryngeal view grade was poor and the ML was an important factor.