Title: Craniomandibular osteopathy

'''Craniomandibular osteopathy''', also known as '''lion's jaw''', is a developmental disease in [[dog]]s causing extensive bony changes in the [[mandible]] and [[skull]].  In this disease, a cyclical resorption of normal bone and replacement by immature bone occurs along the inner and outer surfaces of the affected bones.&lt;ref&gt;{{cite web | title = Craniomandibular Osteopathy | work = The Merck Veterinary Manual | date = 2006 | url = http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/91503.htm | accessdate = 2007-02-04 }}&lt;/ref&gt;  It usually occurs between the ages of 3 and 8 months.  Breeds most commonly affected include the [[West Highland White Terrier]], [[Scottish Terrier]], [[Cairn Terrier]], and [[Boston Terrier]].&lt;ref name=Ettinger_1995&gt;{{cite book|author=Ettinger, Stephen J.|author2=Feldman, Edward C.|title=Textbook of Veterinary Internal Medicine|edition=4th|publisher=W.B. Saunders Company|year=1995|isbn=0-7216-6795-3}}&lt;/ref&gt;  It is rare in large-breed dogs, but it has been reported.&lt;ref name=Huch&gt;{{cite journal |author=Huchkowsky S |title=Craniomandibular osteopathy in a bullmastiff |journal=Can Vet J |volume=43 |issue=11 |pages=883–5 |year=2002 |pmid=12497967 |pmc=339767}}&lt;/ref&gt;  Symptoms include firm swelling of the jaw, [[drooling]], pain, and difficulty eating.  

It is an inherited disease, especially in Westies, in which it has been recognized as an [[recessive gene|autosomal recessive]] trait.&lt;ref name=Hazewinkel&gt;{{cite web | last = Hazewinkel | first = Herman A.W. | title = Hereditary Skeletal Diseases in Companion Animal Practice | work = Proceedings of the 29th World Congress of the World Small Animal Veterinary Association | date = 2004 | url = http://www.vin.com/proceedings/Proceedings.plx?CID=WSAVA2004&amp;PID=8729&amp;O=Generic | accessdate = 2006-08-26 }}&lt;/ref&gt;  [[Canine distemper]] has also been indicated as a possible cause,&lt;ref name=Ettinger_1995/&gt; as has ''[[Escherichia coli|E. coli]]'' infection, which could be why it is seen occasionally in large-breed dogs.&lt;ref name=Huch/&gt;  Growth of lesions will usually stop around the age of one year, and possibly regress.  This timing coincides with the normal completion of endochondral bone growth and [[Endochondral ossification|ossification]].  If the disease is extensive, especially around the tympanic bulla ([[middle ear]]), then the [[prognosis]] is guarded.

A similar disease seen in young [[Bullmastiff]]s is known as '''calvarial hyperostotic syndrome'''.  It is also similar to human [[infantile cortical hyperostosis]].  It is characterized by irregular, progressive bony proliferation and thickening of the cortical bone of the [[calvaria (skull)|calvaria]], which is part of the skull.  Asymmetry of the lesions may occur, which makes it different from craniomandibular osteopathy.  Symptoms include painful swelling of the skull, fever, and [[lymph node]] swelling.&lt;ref&gt;{{cite journal |vauthors=McConnell J, Hayes A, Platt S, Smith K |title=Calvarial hyperostosis syndrome in two bullmastiffs |journal=Vet Radiol Ultrasound |volume=47 |issue=1 |pages=72–7 |year=2006 |pmid=16429988 |doi=10.1111/j.1740-8261.2005.00108.x }}&lt;/ref&gt;  In most cases it is self-limiting.&lt;ref&gt;{{cite journal |vauthors=Pastor K, Boulay J, Schelling S, Carpenter J |title=Idiopathic hyperostosis of the calvaria in five young bullmastiffs |journal=J Am Anim Hosp Assoc |volume=36 |issue=5 |pages=439–45 |year=2000 |pmid=10997521}}&lt;/ref&gt;

==References==
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[[Category:Dog musculoskeletal disorders]]

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