Medial Internal Pterygoid Muscle of the Male Head and Neck, Sagittal View

Description

Running along the medial surface of the mandibular ramus, the medial pterygoid (internal pterygoid) is exposed within the infratemporal fossa on a sagittal section of the male head and neck. Its muscular fascicles descend inferolaterally from the pterygoid fossa of the sphenoid and adjacent palatine bone to a broad tendinous insertion on the medial aspect of the mandibular angle and ramus, opposite the masseter on the lateral side. Superior to the muscle belly lie the maxillary region and zygomatic arch, while anteriorly the mandibular body and dentoalveolar structures anchor the masticatory apparatus. Inferiorly, the hyoid and laryngeal framework sit anterior to the cervical vertebrae, with the sternocleidomastoid and strap muscles framing the neck in profile. This sagittal presentation clarifies why the medial pterygoid is often described as a sling with the masseter, generating mandibular elevation and assisting contralateral excursion during chewing. The relationship of its deep surface to the parapharyngeal space and pterygomandibular region matters clinically, since deep odontogenic infection from the posterior mandible can track into the pterygomandibular space, producing trismus that reflects medial pterygoid spasm. For procedural anatomy, the muscle’s position relative to the mandibular foramen region informs the path of an inferior alveolar nerve block, where needle placement too medial can enter the pterygomandibular space and irritate the muscle. Use this artwork for head and neck anatomy teaching blocks on muscles of mastication, dental anesthesia training materials, and surgical texts discussing deep fascial spaces of the jaw and upper neck. It also fits radiology and oral and maxillofacial surgery publications that correlate sectional anatomy with CT or MRI planes at the mandibular ramus and infratemporal fossa. Anatomical accuracy verified by SciePro's Medical Advisory Board.