Styloid

Styloid is an adjective meaning stylus-like, and in anatomy it is used to describe slender, pointed projections known as styloid processes. The term derives from the Greek stylos, meaning stake or pillar. Styloid projections occur in several bones and serve as attachment points for muscles and ligaments.

The most prominent example is the styloid process of the temporal bone, a slender projection that extends downward and anteriorly from the inferior aspect of the temporal bone near the mastoid region. It provides attachment for the stylopharyngeus, styloglossus, and stylohyoid muscles, as well as the stylomandibular ligament. The stylohyoid ligament runs from the styloid process to the hyoid bone and can ossify with age or pathology. The facial nerve exits the skull through the stylomastoid foramen, which lies between the styloid and mastoid processes.

Beyond the temporal bone, there are styloid processes at other bones, most notably the distal ends of the radius and ulna. The radial styloid process projects at the wrist and serves as an attachment site for wrist ligaments, while the ulnar styloid process projects from the distal ulna and contributes to the stability of the distal radioulnar joint.

Clinical significance includes elongated styloid processes or calcified stylohyoid ligaments, which can cause Eagle syndrome. This condition may present with throat pain, a sensation of a foreign body, dysphagia, or referred otalgia. Diagnosis relies on imaging such as panoramic radiographs or CT to measure styloid length. Treatment ranges from observation for asymptomatic cases to surgical styloidectomy (intraoral or extraoral) for symptomatic patients.