Mandibular osteodistraction for correction of deep bite class II malocclusion in a horse.

The research article discusses the use of a new technique, called mandibular osteodistraction, to correct severe brachygnathia, a type of malocclusion or jaw misalignment, in a horse. This method showed success in elongating the mandible and achieving stable correction of the issue with minor complications.

Methodology

• The researchers carried out a clinical report on a Warmblood horse, specifically a colt, that was affected with brachygnathia, a condition characterized by a shorter lower jaw.
• The team employed mandibular osteodistraction. They initiated this by creating an osteotomy site – a purposeful cut into the bone of the lower jaw.
• Subsequently, a half ring external fixator was utilized and fixed on both sides of the osteotomy site. This device helps in stabilizing bone and soft tissue at a distance from the operative or fracture focus.
• A bite plate was inserted at the upper incisors to promote occlusion or alignment between the upper and lower jaw.

Results

• The horse was subjected to a 5-day latency period after the procedure, following which the team applied distraction at a rate of 1 mm/day until the overjet, or horizontal projection of upper teeth over the lower ones, was visually considered normal.
• With this method, the researchers were able to achieve mandibular elongation and effective correction of the horse’s brachygnathia with no major complications recorded.
• Six months after the treatment, the reduction in overjet was found to be stable, indicating the successful long-term efficacy of the process.

Conclusions

• The study concludes that mandibular osteodistraction can be an effective treatment for severe brachygnathia in yearlings.
• Among the benefits of distraction osteogenesis is the progressive elongation of the mandible, which allows for concurrent bone remodeling and adaptation of the soft tissue.
• The researchers also suggest that this technique can render useful to correct severe mandibular incisor malocclusion in horses that are outside their maximal growth phase.