A tangential radiographic projection for investigation of the equine temporomandibular joint.

This research article demonstrates a new method of tangential radiographic projection for examining horse’s temporomandibular joint (TMJ). The authors report this method improves image quality and enables clearer viewing of the TMJ without obstruction from other elements, hence proving to be efficiently applied on sedated horses.

Research Methodology

The research used two methodologies:

• The first one was descriptive study involving:
  • Cadaveric horse skulls (11 in number)
  • Eight living horses that had a history of quidding (dropping food from the mouth while chewing) or headshaking
• The second method involved radiographic imaging of the TMJ. Here, tangential radiographic projections were taken from a cadaveric skull before and after injecting radiographic contrast into the joint. The process was repeated after dissecting the TMJ and placing a wire along the mandibular condyle’s articular surface. The researchers took three different tangential radiographs from each of the TMJs of ten skulls at three different angles to the dorsal plane (75, 70, and 65 degrees). The effectiveness of these different angles was evaluated by four observers who weren’t aware of the projection angle. They also used statistical tools, like the Friedman analysis of variance, to calculate the variation in observation.

Results

• The tangential radiographic projections aided in viewing the lateral half of the TMJ without any superimposition from other structures.
• Among the different angles tested, the 70-degree projection to the dorsal plane provided significantly better views.
• No significant variation in observation was found among the different observers.
• The technique was safely applied on standing, sedated horses with excellent image quality.

Conclusion

The study suggests that tangential radiography of the TMJ can act as a complementary tool, offering additional insights from clinical examination and ultrasonography before referring for more advanced imaging techniques. This innovation can improve diagnosis and treatment processes for equine oral health issues.