Complementary Radiographic Projection for Evaluation of the Conchal Sinuses and Bullae in Horses.

Radiographic examination of the skull is a well-established and indispensable procedure for the diagnostic evaluation of dental and paranasal sinus disorders in horses. Complementary projections make significant contributions to radiographic diagnosis in nasal conchae disorders. This article describes a complementary radiographic projection designed for the evaluation of the conchal sinuses and bullae in horses. Six equine cadaveric heads were used. Specimens were dissected, and openings were created in the ventral and dorsal nasal conchae for the introduction of radiopaque material. The new radiographic projection was named lateral 75° dorsal-lateral ventral oblique view. This projection was obtained with the mandibular rami resting on the imaging plate and the mandible displaced toward the side of interest (partial excursion). The X-ray beam was directed dorsoventrally, slightly angled toward the side of interest (left or right offset mandible dorsoventral view), and centered at an imaginary line connecting the tips of the facial crests. The lateral 75° dorsal-lateral ventral oblique view provided enhanced visualization and allowed correct identification of equine conchal structures. Lateral displacement of the mandible and the 75° angle of inclination to the vertical plane eliminated the superimposition of anatomical structures, facilitating radiographic image interpretation and increasing diagnostic accuracy. This complementary projection is recommended in all cases of sinonasal disorders in horses.