Anatomical Considerations in the Twin Block Technique for the Treatment of Masticatory Myofascial Pain: An Anatomical Review.

Myofascial pain (MFP) is one of the most frequent temporomandibular disorders (TMDs), primarily affecting the masseter and temporalis muscles. Various treatment strategies have been developed, including trigger point injections (TrP) and nerve blocks. Among these, the twin block technique has recently emerged as a promising, minimally invasive approach for simultaneously anesthetizing the masseteric and anterior deep temporal nerves through a single extraoral injection. This review presents the anatomical considerations essential for the application of the twin block technique. The course, branching patterns, and relationships of the masseteric and deep temporal nerves with adjacent vascular structures are described based on the current anatomical literature. A comparison is also made of isolated nerve blocks and the twin block, highlighting procedural protocols, clinical advantages, and safety profiles. The anatomical proximity between the masseteric and deep temporal nerves supports the rationale for a single-puncture approach, which can effectively reduce muscle tone, inhibit nociceptive input, and silence multiple trigger points simultaneously. In addition to its therapeutic benefits, the twin block can serve as a diagnostic tool to differentiate muscular from joint or odontogenic pain. In conclusion, the twin block technique offers a precise and efficient method for managing masticatory myofascial pain, provided that detailed anatomical knowledge is applied to ensure procedural accuracy, a low incidence of adverse effects, and patient safety.