Styloid Process of Temporal Bone

The styloid process of temporal bone is a slim and sharp portion of the temporal bone. It protrudes anteroinferiorly via the inferior surface of the temporal bone.

Styloid Process of Temporal Bone

Structure

Styloid process is a thin and long skeletal process of temporal bone of around 1 inch in length, which is anterolaterally located towards the mastoid process, also inferiorly and posteriorly towards the external auditory meatus. Its base is enclosed by tympanic plate to some extent. From the lower surface of the tympanic plate, it spreads out downward and forward. The facial nerve externally traverses it.

Relations

1. Stylomastoid foramen is located posterior towards the root of the styloid process.
2. Hyoid bone is suspended by styloid processes of temporal bone via stylohyoid ligaments.
3. Facial Nerve travels near styloid process.
4. The deep layer of deep cervical fascia passes deep to the parotid gland to get attached to the lower border of the tympanic plate and styloid process of the temporal bone.
5. The stylomandibular ligament which divides the parotid gland from submandibular gland is created by the condensation of the deeper layer of deep cervical fascia which stretches between the styloid process and the angle of mandible.
6. Retromandibular fossa is medially bounded by styloid process.
7. Styloglossus, stylopharyngeus, and stylohyoid muscles cover the styloid process and are attached to distal part of it.
8. Stylohyoid muscle arises from the posterior surface of the styloid process.
9. Styloglossus muscle arises from front of the tip of styloid process and adjoining part of stylohyoid ligament.
10. Styloid process is medial limit of parotid gland.
11. The styloid process and its muscles separate the gland the parotid gland from:
    • Internal carotid artery
    • Internal jugular vein
    • Last four cranial nerves
12. Posterior wall of infratemporal fossa is created by styloid process of temporal bone.

Variations

• Normal – less than 3 cm.
• Elongated – more than 3cm.
• Pseudoarticulated
• Segmmented