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Mandibular Fractures - Cat & Dog (view source)
Revision as of 09:11, 8 September 2011
, 09:11, 8 September 2011no edit summary
=Small Animals=
==Introduction==
'''[[Skull and Facial Muscles - Anatomy & Physiology|Mandibular fractures]]''' are commonly seen in dogs and cats. With cats they often part of the '''[[High-Rise Syndrome|high-rise syndrome]]''', when a cat falls from a height and suffers facial trauma as a result, or as a consequence of a '''road traffic accident'''. Canine mandibular fractures are normally caused by '''fighting''' or other '''trauma'''. Fractures can also occur in both species as a result of '''dental disease, metabolic disease and neoplasia'''.
==Signalment==
'''Symphyseal fractures''' are most common in '''cats''', particularly entire males as they have a tendency to try and escape buildings to find mating females. Fracture of the '''mandibular body''' is far more common in the '''dog''', and there are no breed, age or sex predispositions.
==Clinical Signs==
Animals may present with a '''history of trauma''' - it is particularly important to check any trauma cases (particularly cats) for mandibular [[Fractures|fractures]]. Otherwise they may have a history of '''dysphagia''' or '''inappetance'''. On physical exam '''instability of the jaw''', '''malocclusion, halitosis and oral pain''' may be evident. Often mandibular body fractures are open, therefore there may be an '''open wound''' over the fracture site.
==Treatment==
The method of fracture fixation varies according to the type of fracture. However the aims of the fixation is always the same:''' to restore normal, functional occlusion, to avoid iatrogenic damage to teeth, achieving stable fixation that encourages healing and early return to function'''.
===Symphyseal Fractures===
Symphyseal fractures are repaired using '''circumferential wire'''. An skin incision should be made in the ventral mandible at the level of the mandible. The wire (0.5-0.7mm gauge - dependant on the size of the animal) should then be guided around the lateral borders of the mandible using an 18G hypodermic needle. The fracture should be aligned and the wires tightened by twisting them together using '''wire-tightening pliars'''. The wire is then cut short and places flush with the skin. The skin incision closed with a single suture. Healing occurs in '''5-7 weeks''', at which point the wire can be removed.
===Mandibular Body Fractures===
Fractures of the mandibular body are normally more complex and healing takes approximately''' 9-10 weeks'''. Numerous methods available for fracture stabilisation:
'''Conservative treatment''':
Conservative treatment can be attempted but it is associated with high complication rates and slow recovery.
'''Interarcade canine acrylic bonding (ICAB)''':
This method uses acrylic dental composite to bond the mandibular and maxillary canine teeth and stabilise the fracture. It is necessary to clean and acid etch the teeth before a thin layer of dental adhesive is applied to the canine teeth. Dental adhesive and the composite are applied to the canines, with the fracture held in reduction until the composite has dried. t is a fairly simple, cheap and effective method.
'''Tape muzzle''':
A tape muzzle can be used in dogs to stabilise the fracture before it is repaired surgically or in cases with financial constraints. It is also suitable for ramus fracture stabilisation. It cannot be used in cats, brachycephalic dogs and not compliant patients.
'''Interdental wire and acrylic bonding (IWAB)''':
This method cannot be used in cats but is a effective and cheap technique for use in the dog. The wire and bonding are placed on the dorsal tension side of the mandible, causing minimal iatrogenic damage and good stabilisation.
'''Interfragmentary wiring''':
This technique is not recommended as it rarely achieves appropriate stabilisation and tends to cause damage to the surround teeth and soft tissues.
'''External skeletal fixator''':
ESF pins connected by acrylic frames provide good fracture stabilisation. The acrylic is light, cheap and easy to apply, however it is important to avoid damage to adjacent structures when placing the pins.
'''Bone plates''':
Bone plates cane be placed at the junction of the body and ramus of the mandible, at the ventral border of the
mandibular body and the mid-buccal surface of the mandible.
'''Hemimandibulectomy''':
This is considered a salvage procedure.
===Ramus fractures===
Ramus fractures may be treated either '''conservatively''' or with '''interdental wire and acrylic bonding (ICAB)''', and healing is normally achieved within '''6 weeks'''.
'''Placement of an oesophageal feeding tubes is recommended for all mandibular fracture cases other than simple symphyseal fractures to prevent nutritional complications.'''
If the fracture is open, then suitable '''[[Antibiotics|antibiotics]]''' should be given to prevent [[Osteomyelitis|osteomyelitis]] and soft tissue infection. Antibiotics should also be given to any animals with dental disease.
==Prognosis==
The prognosis for '''symphyseal''' and '''ramus''' fractures is '''good'''. '''Complications''' are much more common with fractures of the mandibular '''body''' - particularly if '''[[Category:Teeth - Anatomy & Physiology|teeth]]''' are involved in the fracture, and prognosis will depend on whether or not these complications occur. They include '''poor occlusion, implant failure, infection of the bone or soft tissue, joint disease, non-union and malunion'''.
=Large Animals=
==Introduction==
==Introduction==
'''Mandibular fractures''' often occur when animals catch their '''lower jaw''' for example on ''' wire fencing''', '''the rings on the stable walls''' or under a '''manger'''. Normally the rostral mandible is '''avulsed''' as they try to free themselves by pulling backward. Fractures can also occur in the ramus of the mandible, however these are much less common.
'''Mandibular fractures''' often occur when animals catch their '''lower jaw''' for example on ''' wire fencing''', '''the rings on the stable walls''' or under a '''manger'''. Normally the rostral mandible is '''avulsed''' as they try to free themselves by pulling backward. Fractures can also occur in the ramus of the mandible, however these are much less common.
{{Learning
{{Learning
|flashcards = [[Equine Orthopaedics and Rheumatology Q&A 03]]
|flashcards = [[Equine Orthopaedics and Rheumatology Q&A 03]]<br>[[Small Animal Orthopaedics Q&A 03]]
}}
}}
=References=
Glyde, M & Lidbetter, D (2003) '''Management of fractures of the mandible in small animals''' ''In Practice 2003;25:570-585''
Lewis, DD & Parker, RB & Bloomberg, MS (1998) '''Self-Assessment Colour Review Small Animal Orthopaedics''' ''Manson''
May, SA & McIlwraith, CW (1998) '''Equine Orthopaedics and Rheumatology Self-Assessment Colour Review''' ''Manson Publishing Ltd''
May, SA & McIlwraith, CW (1998) '''Equine Orthopaedics and Rheumatology Self-Assessment Colour Review''' ''Manson Publishing Ltd''
RVC staff (2009) '''Urogenital system''' RVC Intergrated BVetMed Course, ''Royal Veterinary College''
Tremaine, H (1997) '''Dental care in horse''' ''In Practice 1997 19: 186-19''
Tremaine, H (1997) '''Dental care in horse''' ''In Practice 1997 19: 186-19''
[[Category:Musculoskeletal Diseases - Horse]]
[[Category:Musculoskeletal Diseases - Horse]]
[[Category:Expert Review - Horse]]
[[Category:Expert Review - Horse]]
[[Category: To Do - Siobhan Brade]]
[[Category:To Do - Manson review]]