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.
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.
Small loose fragments with no soft tissue attachment should be removed to avoid the formation of sequestrum.
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.
The mandibular reconstruction plate is anatomically contoured in 3 dimensions using the appropriate bending pliers.
The length of the plate should allow for 2-3 bicortical locking screws on both sides of the fracture.
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.
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.
The rostral screw closest to the fracture site should be inserted first alternating as illustrated until all screws are inserted.
The screw length is determined by a depth gauge measurement. Preoperative CT measurements can be used to estimate the screw length for planning purposes.
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.
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.