Inferior Alveolar Nerve Block Anatomy — MFDS Part 1 MCQ

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ModerateAnatomy (Head & Neck)Inferior Alveolar Nerve Block AnatomyMFDS Part 1

During administration of a conventional direct (Halstead) inferior alveolar nerve block, which muscle is penetrated by the needle before it enters the pterygomandibular space?

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Correct answer: A — Buccinator

The correct answer is **A, buccinator**. In the conventional direct inferior alveolar nerve block, the needle penetrates the oral mucosa and buccinator before entering the pterygomandibular space, where it is advanced towards the medial surface of the mandibular ramus near the mandibular foramen. The medial pterygoid forms the medial boundary of the space and should not be intentionally penetrated; injection into it may contribute to post-injection trismus. The masseter lies lateral to the mandibular ramus and is not on the intraoral needle path. The lateral pterygoid is superior to the conventional target region. The superior pharyngeal constrictor is attached to the posterior aspect of the pterygomandibular raphe and lies medial to the intended route.

Reference: Vutukuri R, et al. The pterygomandibular raphe: a comprehensive review, anatomical relationships and Figure 4, 2024. https://pubmed.ncbi.nlm.nih.gov/21623801/