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This information is provided by Provet for educational purposes only.

You should seek the advice of your veterinarian if your pet is ill as only he or she can correctly advise on the diagnosis and recommend the treatment that is most appropriate for your pet.

Dysplasia of the temporomandibular joint is seen from time to time in young dogs

The cause is unknown but dysplasia of the temporomandibular joint, resulting in recurrent subluxation has been reported to occur in the following breeds :

  • Bassett Hounds, Irish Setters and St Bernards - coronoid malpositioning
  • Boxers and Retrievers - pain and open-mouth locking, but no malpositioning
  • Dalmatians

Signs include :

  • Locking of the mouth in an open position
  • Difficulty/inability to eat normally
  • Pain

Owners usually present the animals to a veterinarian with the mouth locked in an open position. Sometimes there is swelling over the zygomatic arch where the coronoid is displaced

The disorder is diagnosed on plain skull radiographs with the following radiographic findings :

  • Divergent TM joint spaces
  • Shallow mandibular fossae
  • New bone deposition - due to secondary degenerative joint disease
  • Lateral displacement of the coronoid process

The subluxation may be replaced manually whilst conscious, or under general anaesthesia. Surgical treatment may be needed in difficult cases  :

  • Partial resection of the zygomatic arch (if the coronoid displaces laterally) OR
  • Removal of the mandibular condyle

Surgical treatment is usually followed by a complete return to normal function, but the condition can be bilateral.


Updated October 2013