Injectate spread in ultrasound-guided inferior alveolar nerve block: a cadaveric study

A new and simplified extraoral approach for inferior alveolar nerve block: a cadaveric study and clinical case reports

PURPOSE

Inferior alveolar nerve (IAN) and lingual nerve (LN) blocks are commonly performed using the intraoral landmark techniques. However, these methods have a risk of unanticipated nerve and arterial injury or a higher failure rate. We developed a novel extraoral approach for the IAN and LN blocks, the "inferior alveolar nerve block mandibular angle approach (IANB-MA)," using ultrasound guidance. The mechanism of action of this nerve block was examined anatomically, and its clinical feasibility was reported.

METHODS

We performed the IANB-MA on four cadavers using different dye volumes (2, 4, 6 and 8 mL). The ultrasound probe was placed on the lower edge of the mandibula of each cadaver, and the needle was advanced to the mandibular inner surface. Blue acrylic paint solution was injected, and its spread was evaluated by dissection.

RESULTS

Our study showed that the medial pterygoid muscle fascia was stained in all cadavers. The dye reached the LN consistently, and the IAN was stained with higher volumes (6 mL and 8 mL). The pterygomandibular space was filled with 6 mL and 8 mL of the dye. The IANB-MA successfully reduced pain in three patients with trigeminal neuralgia, tongue or jaw pain.

CONCLUSIONS

The IANB-MA is a novel ultrasound-guided approach to the IAN and the LN. The clinical feasibility and effectiveness of this technique were confirmed in our patients. It may be a good alternative analgesic approach to other conventional approaches.

Perioperative Analgesia Using an Indwelling Catheter to Deliver an Inferior Alveolar Nerve Block: A Case Report

A 74-year-old male was diagnosed with osteomyelitis of the left mandible requiring marginal mandibulectomy under general anesthesia. However, the patient's pulmonary function tests demonstrated findings consistent with severe chronic obstructive pulmonary disease, classified as stage III. The consulting pulmonologist explained the increased risk of respiratory complications associated with general anesthesia and advised against its use. Therefore, we opted to perform the surgery under moderate sedation using 0.2% ropivacaine administered via bilateral ultrasound-guided inferior alveolar nerve blocks (UGIANBs) and an indwelling catheter with a pump for continuous perioperative local anesthesia and prolonged postoperative analgesia. This approach delivered excellent local anesthetic effects without any need for rescue medications or complications. Use of UGIANBs along with an indwelling catheter and pump may provide adequate local anesthesia and postoperative analgesia in patients with contraindications for general anesthesia.

Mouth-Opener Technique for Ultrasound-Guided Inferior Alveolar Nerve Block: A Case Series of Extraction of Impacted Mandibular Third Molars

Extraction of the impacted mandibular third molar (IMTM) is common in oral surgery, but its postoperative pain is severe. Ultrasound-guided inferior alveolar nerve block (UGIANB) is an analgesic technique in the mandibular nerve region. We describe UGIANB using a mouth opener and report the cases with a good postoperative course. Six patients underwent the extraction of bilateral IMTMs under general anesthesia. After surgery, we performed UGIANB and administered 5 mL of 0.375% levobupivacaine on each side. The postoperative numerical rating scale pain scores were 1 (0-2) and 2.5 (0-5) (mean (range)), postoperative day one and seven, respectively. The postoperative quality of recovery-40 scores were 188.5 (8.1) and 191.7 (7.6) (mean (SD)), postoperative day one and seven, respectively. No procedural complications were encountered. We performed UGIANB with a mouth opener on a patient with IMTM extraction and were able to provide safe and good analgesia.

A Novel Pain Relief Approach for the Treatment of Multiple Dental Caries and Pulpitis

Anxiety and stress toward treatment can hamper treatment completion in patients with dental caries and pulpitis. Therefore, effective management of post-treatment pain is important because poor pain management can lead to patient dissatisfaction. Ultrasound-guided nerve blocks provide good postoperative analgesia in maxillofacial surgeries. These surgeries can be performed under general or local anesthesia without complications. Here, we present the case of a patient with dental phobia who was successfully treated with these techniques. The patient was a 22-year-old woman with a history of manic-depressive illness who presented with 23 decayed teeth. She had previously undergone vital pulp therapy; however, post-treatment pain led to treatment-related stress, and the patient discontinued the dental treatment. She preferred the dental treatment to be completed with as little pain as possible and wanted to avoid a pulpectomy. The patient’s history of heavy use of non-steroidal anti-inflammatory drugs (NSAIDs) made her resistant to NSAIDs. As a result, the analgesic effect of NSAIDs could not be expected. After intravenous midazolam and propofol sedation, an ultrasound-guided inferior alveolar nerve block was performed bilaterally, and 0.375% ropivacaine was used as a local anesthetic. The patient did not complain of post-operative pain, and no post-operative analgesics were required.