**4. Akinosi-Vazirani closed-mouth mandibular nerve block**

Two dentists independently described the closed mouth mandibular nerve block as an alternative to the IANB. In 1977, Akinosi [14] brought this method to the attention of educators, but they soon realized that this technique had been published by Vazirani in 1960. [15] This is indicated particularly if the patient has trismus or the dentist has difficulty seeing the intraoral landmarks used for the SIANB.

What makes this technique unique is that the patient's mouth is closed. The aim is to place the needle tip between the ramus and the medial pterygoid muscle. Since the mouth is closed, seeing the intraoral landmarks can be difficult. A curve at approximately 15° to 30° angle toward the ramus can help minimize the chance of the needle being inserted into the medial pterygoid muscle [15].

Inside the mouth, the bone reference is essentially the same as it is for the SIANB and Gow-Gates methods. We palpate the external oblique ridge of the anterior surface of the ramus and then move the thumb superiorly to palpate the coronoid. The temporal muscle attaches here, and the needle should not enter this sensitive structure. Thus, in a lateral plane, the insertion point is medial to the coronoid process and lateral to the maxillary tuberosity. In superoinferior plane, this insertion point is at the height of the mucogingival junction of the upper teeth, with the tissue retracted laterally, the dentist should insert the needle in a posterior direction [14, 15].

The syringe should be at the level of the mucogingival junction of the upper molars, parallel to maxillary occlusal plane and as close to the maxillary mucosa as possible without touching it. We move the syringe such that the needle moves laterally and posteriorly. Once the needle is inserted 25 mm (for an average adult patient) to stop the advancement of the syringe and administer one full cartridge after a negative aspiration [10,15].

The purpose of using the Akinosi-Vazirani technique is to fill the pterygomandibular space with local anesthetic, bathing the inferior alveolar, lingual and mylohyoid nerves with anesthetic solution. Using Akinosi-Vazirani technique should result in no bony references being hit. The nerves anesthetized by the Akinosi- Vazirani technique include the inferior alveolar and its branches (incisive and mental), lingual, mylohyoid and buccal (approximately 75 percent of the time). A separate buccal nerve block is not needed because successful anesthesia of the buccal nerve is common when this technique is used. The begining of anesthesia is intermediate (five to seven minutes) compared with that of the SIANB and the Gow-Gates technique [10,14,15].
