JVD 2009 2 Imaging and Management of a Caudal Mandibular Fracture in an Immature Dog Christopher J. Snyder, Jason W. Soukup, William R. Gengler Flashcards
What are common causes of mandibular fracture?
trauma, severe periodontal disease, neoplasia, and iatrogenic fracture during tooth extraction
Describe the fracture in these two CT images.
The fracture courses through the right caudal mandibular canal (A)
and dorsal to the right developing mandibular second molar 410 (B)
Which muscles were elevated from the vbentral mandible to allow visulaisatiokn of the fracture distal to the developing 410?
The rostral aspects of the digastricus and the mylohyoideus muscles were bluntly elevated from insertions on the ventral mandible to allow complete visualization of the fracture
Why was the fracture considered unfavourable?
The fracture was considered unfavorable based on the fracture line extending caudoventrally resulting in the distraction of the fracture when the muscles of
mastication exert dorsal forces on the caudal aspect and the digastricus muscle exerts a ventral and caudal force on the rostral segment.3
What creates favourable conditions for fracture repair?
Favourable conditions are maintained by minimizing movement between fracture edges, maximizing contact between bone edges with slight compression, and the preservation of vascular supply all of which encourage new bone formation with minimal periosteal callus formation
What are the typivcal guidelines for fracture repair?
The guidelines for fracture repair technique include apposition of the fracture fragments and rigid fixation with slight compression.
What happens when there is excessive tension at the fracture site or increased callous formation
Excessive tension or movement promotes fibrous tissue formation within the callus which destabilizes the healing fracture negating the formation of a template for bone
formation
What special age related considerations are needed in dogs under 1 year of age with mandibular fractures.
Animals that are actively growing may suffer disruptions in growth and
development leading to facial deformities
A second age-related complication includes damage to the unerupted permanent dentition. Damage to developing teeth may cause subsequent enamel hypocalcification, impaction and dentigerous cyst formation and or pulpal necrosis.
In a review of human mandibular fractures what percentage of tooth buds located in the fracture line demonstrated abnormalities in development?
45 % of developing teeth demonstrated abnormal formation or growth
including signs of deficient root formation, abnormal root formation, obliteration of the pulp chamber, impaction, arrested growth or external resorption
Why was interdental wiring and intraoral acrylic splinting considered less than ideal?
The age of the growing dog and location of the fracture, intraoral splinting would have been very difficult to utilize in this dog due to the very caudal nature of the fracture and
the lack of dentition. The small surface area of deciduous dentition rostral to the fracture as well as the expected exfoliation and successional tooth eruption would have all made this technique less than ideal.
