Authors of section

Author

Boaz Arzi

Executive Editor

Amy Kapatkin

General Editor

Frank Verstraete

Open all credits

Plate fixation

1. Principles

Restoration of occlusion and normal anatomy is crucial to avoid long term complications such as malocclusion, malunion, nonunion, refracture, facial asymmetry and loss of function.

2. Approach

Pharyngeal intubation is needed to assess and maintain occlusion throughout and following the surgery.

With the patient in dorsal recumbency, a ventral approach to the mandibular body or bodies is performed. The incision should expose enough intact bone to place at least two screws on both sides of the fracture.

Dog mandible body bilateral simple fracture ventral approach

The mandible and maxilla should be closed in the desired occlusion. This will align the bones into normal occlusion.

26 or 28 gauge wire are used. The wires are looped around all four canine teeth and twisted together to lock the mouth in normal occlusion.

Dog mandible body unilateral simple fracture mouth locked in normal occlusion

3. Reduction

Fracture reduction is accomplished with 1-2 periosteal elevators placed at the fracture site to lever the caudal fragment into reduction to restore the normal anatomy. Bone holding forceps and sometimes digital reduction can be used.

Dog mandible body unilateral simple fracture reduction

Small loose fragments with no soft tissue attachment should be removed to avoid the formation of sequestrum.

Dog mandible body unilateral simple fracture fragment removal

4. Fixation

Plate selection and contouring

For a medium or large breed dog, a single 2.4/3mm titanium locking mandibular reconstruction plate is used. For small breed dogs and cats, a 2.0mm titanium locking plate or mandibular reconstruction plate is used.

Titanium locking mandibular reconstruction plate

The mandibular reconstruction plate is anatomically contoured in 3 dimensions using the appropriate bending pliers.

The mandibular reconstruction plate is anatomically contoured using bending pliers

The length of the plate should allow for 2-3 bicortical locking screws on both sides of the fracture.

Plate application

The plate is applied to span the fracture site and screw placement must avoid the mandibular tooth roots. The plate is placed ventral to the tooth roots and above the mandibular canal. A single plate is sufficient to stabilize the mandible.

Note: In small dogs and cats, due to limited bone stock, the screws often penetrate the mandibular canal.

Dog mandible body unilateral simple fracture plate application

Plate fixation

The plate is held in place using bone holding forceps. A locking drill guide is screwed into the plate to allow precise drilling of the hole.

Dog mandible body bilateral simple fracture plate fixation

The rostral screw closest to the fracture site should be inserted first alternating as illustrated until all screws are inserted.

Dog mandible body bilateral simple fracture screw plate fixation

The screw length is determined by a depth gauge measurement. Preoperative CT measurements can be used to estimate the screw length for planning purposes.

Dog mandible screw length measurement

5. Closure

The soft tissues are closed routinely in 3 layers.

6. Case example

Fixation of bilateral mandibular body fracture using two 2.0mm titanium locking plates through two separate ventral approaches.

Dog mandible body bilateral fracture plate fixation

7. Aftercare

Multimodal analgesia is recommended. Non-steroidal medication for 10-14 days and opioids for the first 5 days post-surgery as needed. Antibiotic therapy is prescribed for a period of 10-14 days following surgery.

Soft food should be fed for the first 14 days, followed by a gradual return to eating kibble over 2 weeks. Rough play (i.e., tug of war) should be avoided for the first 3 months after surgery.

Suture removal is performed 10-14 days after surgery.

A radiographic recheck is performed every 6 weeks until the fracture is healed. The plate is not removed after the fracture is healed.