Changes

==Introduction==

==Introduction==

The pressure of opposing cheek teeth leads to stoppage of growth and alteration in the pulp cavity, germinal tissues accentuates the hitherto normal angulation of the teeth. The rabbit’s cheek teeth are normally tilted: uppers, laterally towards the cheeks; lowers, medially towards the tongue. This is accentuated once the growth (germinal) tissues are affected. This also means that growth may stop – a very unnatural state of affairs for the species. Sometimes these abnormal growing patterns result in the formation of discrete spurs with extremely sharp edges.

Alterations in the position, shape and structure of the molars leads to malocclusion of the cheek teeth. Deterioration of tooth and bone quality can also contribute to the development of malocclusion.

The spurs can also lead to loosening of the teeth – lever effect.  

The pressure of opposing cheek teeth leads to stoppage of growth and alteration in the pulp cavity and germinal tissues accentuates the hitherto normal angulation of the teeth. In normal rabbits, the cheek teeth are tilted: uppers, laterally towards the cheeks; lowers, medially towards the tongue. This is accentuated once the germinal tissues are affected. Initially the teeth tend to curl then become progressively distored. Sometimes these abnormal growing patterns result in the formation of discrete spurs with extremely sharp edges. This can lead to loosening of the teeth, thus increasing the risk of foreign material entering the socket.

Continuous growth and pressure against the crowns of the teeth in the opposing jaw stops the jaw closing and strains the masseter and temporalis muscles – a vicious cycle leading to atrophy of disuse of the jaw and a further reduction of bone density.   

Continuous growth and pressure against the crowns of the teeth in the opposing jaw stops the jaw closing and strains the masseter and temporalis muscles – a vicious cycle leading to atrophy of disuse of the jaw and a further reduction of bone density.   

Periodontal resorption leads to a loss of the tooth crowns.      

Malocclusion of the cheek teeth can lead to [[Incisor Overgrowth – Rabbit|incisor overgrowth]], and the observation of long protruding incisors might be the first sign of a cheek teeth problem the owner will notice.    

==Clinical Signs==

==Clinical Signs==

Clinical signs relate to the pain experienced and the inability of the rabbits to eat normally:

#Epiphora from the migration of the roots of the molar teeth into the orbit of the eye.

#Swelling around the head and neck, mandibular abscesses, maxillary abscesses

#"[[Clagged Vent – Rabbit|Clagged vent]]" – ingestion of caecotrophs is painful when teeth cut the inside of the buccal cavity

#Restore normal malocclusion:  

 

#The aim is to preserve the tooth and to prevent overgrowth of the opposite one.

'''Digestive disorders''' are often seen: ileus, reduced number of droppings, intestinal obstruction from the ingestion of fur mats.

#Address the underlying cause of the malocclusion.

 

#Monthly or six-weekly prophylactic dentals.

'''Uneaten caecotrophs''' due to a difficulty in reaching and ingesting the droppings. This leads to soiling of the perineal skin and can become fly strike if severe enough.

#Always warn the owner that there is a tendency for the condition to recur.

 

#Over grown molars can be burred back to restore occlusion, at least temporarily

'''Epiphora and dacryocystitis''' due to impingement on the nasolacrimal duct by the elongated roots and the upper incisors, often with secondary bacterial infection.

 

'''Abscesses''' seen as hard lumps along the ventral border of the mandible, or retrobulbar abscesses

 

'''Incisor malocclusion and overgrowth''' due to the lack of correct chewing motion due to cheek teeth malocclusion.

 

'''Pain and anorexia''' due to the spurs on the cheek teeth. There is often profuse salivation and staining of the fur under the chin and on the forelegs.

 

Corrective dentistry cannot restore normal occlusion to maloccluded cheek teeth because of the altered positon, shape and structure of the teeth. Changes in the direction of growth mean that malocclusion recurs and the spurs regrown, often in a matter of weeks. However acquired dental disease is progressive and eventually the germinal layer of the roots is destroyed and the teeth stop growing so trimming is no longer required.

The number of times that the teeth require trimming is variable, but is usually every 6 weeks initially.

===Procedure===

===Procedure===

*Keep the mouth open with a gag.

*General anaesthesia is required and a mouth gag and cheek dilators are extremely useful.

*Dilate the pouches.

*Hold the lip or tongue out of the way with a spatula. This protects the soft tissues.

*Hold the lip or tongue out of the way with a spatula. This protects the soft tissue.

*Dental burrs are the preferred instrument for removing spurs and reshaping cheek teeth, although molar clippers can be used if they are the only tool available.  

*Burr back the excess tooth (or spur) with a medium speed burr (18,000 RPM).  

*Burring should not take more than a minute but, if it does, stop to cool the tooth frequently with a cotton bud soaked in cold water.

*It should taken more than a minute but, if it does, stop to cool the tooth frequently with a cotton bud soaked in cold water.

====Helpful Hints====

====Helpful Hints====

*The nurse should hold the head (by the gag) and pull it forward extending the atlanto- axial joint or use a table-top gag (Veterinary Instrumentation http://www.vetinst.com)

*The nurse should hold the head (by the gag) and pull it forward extending the atlanto-axial joint or use a table-top gag (Veterinary Instrumentation http://www.vetinst.com)

*Rest your forearms on a sand bag, it makes your aim better!

*Rest your forearms on a sand bag, it makes your aim better!

*Keep the tongue pulled forward to prevent cyanosis.

*Keep the tongue pulled forward to prevent cyanosis.

==Extraction of cheek teeth==

==Extraction of cheek teeth==

Extraction of cheek teeth follows the same principles as incisor extraction – special sharp elevators or bent hypodermic needles are used to cut the periodontal ligaments around these box-shaped structures.

Extraction of cheek teeth follows the same principles as incisor extraction – special sharp elevators or bent hypodermic needles are used to cut the periodontal ligaments around these box-shaped structures.

The main indication is facial abscess due to dental disease.

It is not necessary to remove the opposing cheek tooth as an upper tooth occludes with two lower teeth and vice versa. Also, adjacent teeth tend to tip towards any gap that is left.

===Procedure===

===Procedure===

*Hillyer, E. V. (1994) Pet Rabbits. Veterinary Clinics of North America: Small Animal Practice. 24 (1) 25-65

*Hillyer, E. V. (1994) Pet Rabbits. Veterinary Clinics of North America: Small Animal Practice. 24 (1) 25-65

[[Category:Rabbit Dentition]]

[[Category:Rabbit Dentition]]