Which technique is particularly useful in cases of limited mouth opening due to trismus?

• A. Vazirani-Akinosi technique
• B. Inferior alveolar nerve block
• C. Infraorbital nerve block
• D. Mental nerve block

Answer: (A)

In situations where mouth opening is severely limited by trismus, a technique that can be performed with the mouth closed is ideal. The Vazirani-Akinosi closed-mouth mandibular nerve block fits this need perfectly. By guiding the needle medially and superiorly from the mucogingival junction at the height of the maxillary ramus (near the maxillary tuberosity) with the mouth kept shut, this approach reaches the mandibular nerve trunk before the pterygomandibular space, anesthetizing the inferior alveolar and lingual nerves on that side. This provides effective anesthesia of the posterior mandible without requiring wide mouth opening, which is precisely why it’s favored in trismus.

Other blocks rely on opening the mouth wide to access specific canals or foramina: the inferior alveolar nerve block targets the pterygomandibular space but is difficult or unreliable when the mouth cannot open, while the infraorbital and mental nerve blocks anesthetize more anterior maxillary structures or a limited region of the mandible, not addressing the full mandibular nerve distribution needed in many cases of limited mouth opening.