Treatment of a bilateral mandibular fracture in a mare using an intraoral acrylic splint.

This study presents a treatment method for a horse suffering from a bilateral mandibular fracture using an intraoral acrylic splint. The approach, first developed by Collahan and Pascoe (1983), uses a cold-curing resin to construct the oral splint, addressing difficulties tied to the use of orthopaedic implants.

Background

• Mandibular fractures in horses, often caused by direct trauma, were traditionally treated with techniques such as Steinman pins, aerial wire, lag screws or various combinations.
• Particular fractures often required increased stability, and as such, external braces or splints, a Kirschner apparatus, bone plates, and U shaped bars were considered more suitable.
• Drawbacks emerged with the use of orthopedic implants, especially when the fracture was far for sufficient stabilization and risked causing damage to permanent tooth buds or roots.
• Collahan and Pascoe introduced a new technique which used a cold-curing resin to build an oral splint, addressing the limitations of implants and providing efficient stability.

Case Presentation

• A case involving a 12-year-old Thoroughbred broodmare (100 days in foal, with a foal at foot), suffering from a compound bilateral mandibular fracture was presented.
• The mare had slipped in a crush during routine teeth rasping, hitting her head repeatedly on the metal support beams.
• Initial examination revealed instability and crepitus of both jaw rami, the fracture compound into the oral cavity on the left side. Radiological examination confirmed the bilateral fractures of the mandibular rami.
• The mare was treated with various medications, the foal was weaned and she was placed in a yard without feed.

Treatment Procedure

• Next day, the mare was first anesthetized. Veterinary surgeons reduced the compound fracture and sewed up the mucous membrane, following a debridement process.
• They inserted holes in the jawbones and passed through orthopedic wire, before reducing the fracture under tension. The same process was carried out for both jaw sides.
• Single strands of the wire were placed across the oral cavity and passed between the mucous membrane and the tension band wire, leaving the ends open.
• A cold curing resin with a methyl methacrylate base was mixed and poured into each side of the oral cavity and allowed to set around all the wire strands. Ensure no sharp edges were left and normal occlusion and mastication were allowed.
• This created an internal brace or splint, which helped heal the mare’s fractured jaw by maintaining its stability for the duration of the healing process.