Os stylohyoideum
The stylohyoid bone is the longest element of the hyoid apparatus. It connects the skull base to the ceratohyoid. It is part of the structure that supports the larynx and tongue and is involved in swallowing and airway positioning.
Fracture of the stylohyoid can occur from trauma and may affect hyoid function. Relevant in evaluations of head trauma and hyoid apparatus disease. Diagnosis uses imaging.
## Overview Temporohyoid osteoarthropathy (THO) is bony proliferation and fusion of the temporohyoid joint. Fracture or compression in this region damages cranial nerves VII (facial) and VIII (vestib
Progressive proliferative osteoarthropathy of the temporohyoid joint that may cause fusion of the joint and fracture of the petrous temporal bone, damaging CN VII and CN VIII as they traverse the bone
## Overview Fracture of the hyoid apparatus (the bony support of the tongue and larynx) is uncommon and usually traumatic. It can cause difficulty swallowing, throatlatch swelling, pain on manipulati
Head trauma with difficulty swallowing or abnormal head posture should be evaluated.
## Overview Temporohyoid osteoarthropathy (THO) is bony proliferation and fusion of the temporohyoid joint. Fracture or compression in this region damages cranial nerves VII (facial) and VIII (vestibulocochlear), producing facial paralysis, ear droop, reduced tear production, head tilt, and ataxia or balance loss. ## Causes Progressive osteoarthritis of the temporohyoid articulation, often culminating in fracture of the petrous temporal bone or stylohyoid. ## Diagnosis Clinical signs of facial and vestibular dysfunction plus endoscopic or computed tomographic evidence of temporohyoid thickening or fracture. Corneal ulceration from inability to blink is a common complication. ## Treatment Medical management with anti-inflammatories and antibiotics if infection is suspected; surgical ceratohyoidectomy to reduce forces on the joint. Corneal protection is essential. ## Recovery and Prognosis Guarded. Some neurologic signs improve after surgery or with time; residual deficits are common. Corneal scarring can affect vision. ## Prevention None specific. Early recognition of subtle signs may allow intervention before fracture. Signs include: facial paralysis (ear and lip droop); reduced blinking and tear production; head tilt; ataxia; corneal ulceration
Progressive proliferative osteoarthropathy of the temporohyoid joint that may cause fusion of the joint and fracture of the petrous temporal bone, damaging CN VII and CN VIII as they traverse the bone. Signs include: Consult veterinarian for specific symptoms.; Head shaking; difficulty eating; ear rubbing; acute onset vestibular signs (head tilt, nystagmus, circling); facial nerve paralysis; keratitis (corneal ulceration from inability to blink)
## Overview Fracture of the hyoid apparatus (the bony support of the tongue and larynx) is uncommon and usually traumatic. It can cause difficulty swallowing, throatlatch swelling, pain on manipulation, abnormal respiratory noise, and sometimes epistaxis. Resistance to poll flexion may be noted. ## Causes Trauma to the throat or tongue region, or excessive traction. ## Diagnosis Radiographs or computed tomography of the hyoid bones, endoscopy, and clinical signs of dysphagia or local pain. ## Treatment Conservative management with soft feeds and anti-inflammatories for stable fractures. Surgical repair is rarely required. Supportive care for dysphagia. ## Recovery and Prognosis Generally good for uncomplicated fractures. Persistent dysphagia worsens the outlook. ## Prevention Avoidance of throat trauma. Signs include: difficulty swallowing; swelling under the jaw or throat; pain on throat manipulation; abnormal respiratory noise; possible epistaxis
Fracture of the stylohyoid can occur from trauma and may affect hyoid function. Relevant in evaluations of head trauma and hyoid apparatus disease. Diagnosis uses imaging.
Head trauma with difficulty swallowing or abnormal head posture should be evaluated.
See the Stylohyoid Bone (Right) on our interactive 3D horse model. Open 3D Model