Os ceratohyoideum
The ceratohyoid is a short, paired bone that forms part of the hyoid apparatus. It connects the epihyoid (which is often fused with the stylohyoid) to the basihyoid. The hyoid apparatus as a whole suspends the tongue and larynx from the skull and allows the coordinated movements needed for swallowing and airway control. Clinically the ceratohyoid becomes important in temporohyoid osteoarthropathy (THO). In some surgical treatments for THO a ceratohyoidectomy is performed to reduce the lever arm on the temporohyoid joint and decrease the risk of fracture. Guttural-pouch endoscopy assesses the proximal stylohyoid and temporohyoid joint rather than the ceratohyoid itself.
THO can involve the ceratohyoid region. Ceratohyoidectomy is a recognized surgical option. External palpation and endoscopy of the guttural pouches are used to evaluate the hyoid apparatus. CT is the gold standard for diagnosing THO.
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
Difficulty swallowing, nasal discharge, or head-shaking associated with throat pain should be examined by a veterinarian. Do not force the mouth open if the horse shows pain in the hyoid region.
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
THO can involve the ceratohyoid region. Ceratohyoidectomy is a recognized surgical option. External palpation and endoscopy of the guttural pouches are used to evaluate the hyoid apparatus. CT is the gold standard for diagnosing THO.
Difficulty swallowing, nasal discharge, or head-shaking associated with throat pain should be examined by a veterinarian. Do not force the mouth open if the horse shows pain in the hyoid region.
See the Ceratohyoid Bone (Left) on our interactive 3D horse model. Open 3D Model