The stylohyoid connects the styloid process to the hyoid bone, elevating and retracting the hyoid during swallowing as part of the suprahyoid muscle group. Its innervation by the facial nerve rather than the trigeminal or hypoglossal nerves reflects its embryological origin from the second branchial arch. It splits around the digastric intermediate tendon at the hyoid, creating a natural pulley system.
| Origin | Posterior surface of the styloid process of the temporal bone near the base |
|---|---|
| Insertion | Body of the hyoid bone at its junction with the greater horn, splitting around the digastric intermediate tendon |
| Nerve Supply | Facial nerve (CN VII) — the stylohyoid and posterior digastric belly are the only muscles superior to the hyoid innervated by CN VII |
| Blood Supply | Occipital and posterior auricular arteries |
| Actions | Elevates and retracts the hyoid bone during swallowing; Elongates the floor of the mouth |
|---|
Retracting the hyoid posteriorly and superiorly at the onset of swallowing helps tip the epiglottis over the laryngeal inlet and opens the hypopharynx to receive the food bolus from above.
Stylohyoid ossification can cause Eagle syndrome alongside styloid process elongation, producing chronic throat pain and dysphagia from hyoid elevation restriction. Facial nerve palsy affecting the stylohyoid and posterior digastric belly produces a subtle asymmetry in hyoid elevation during swallowing that is identifiable on videofluoroscopy but rarely causes clinically significant dysphagia.
The stylohyoid is not directly palpable but the hyoid bone can be felt elevating during a swallow, and asymmetric elevation suggests stylohyoid or suprahyoid muscle dysfunction.
Stylohyoid ligament ossification or styloid process elongation producing chronic throat pain and restriction of hyoid mobility during swallowing.
