Computed tomographic description of the highly variable imaging features of equine oromaxillary sinus and oronasal fistulae.

This study focused on exploring the Computed Tomography (CT) characteristics of confirmed oronasal and oromaxillary sinus fistulae in horses. The work is important because it sheds light on diagnostic techniques and presurgical planning considerations for fistulae in horses.

Objective of the research

• The research seeks to describe the CT characteristics of confirmed oronasal and oromaxillary sinus fistulae in a sample of horses. These fistulae are problematic conditions for horses, often following the removal or loss of a maxillary cheek tooth.

Methods

• The study made use of a retrospective, case series setup, reviewing horse cases from 2012 to 2017.
• The team used multiple diagnostic tools, specifically oral examination, videoendoscopy, radiography, and computed tomography (CT).
• Inclusion in the study required a head CT acquired at the authors’ hospital, a CT diagnosis of oronasal or oromaxillary sinus fistulae, and a separate confirmation of this diagnosis.
• For the included cases, the team documented signalment, clinical findings, oral examination findings, presence of a confirmed fistula, and method for confirmation of the diagnosis.
• A veterinary radiologist was responsible for reviewing CT results and noting characteristics of the fistulae.

Key Findings

• The team identified a total of 17 fistulae in the horses: 14 oromaxillary sinus fistulae and 3 oronasal fistulae.
• All these fistulae appeared as varied size focal defects in the alveolar bone and often contained a linear tract of heterogeneous material mixed with gas bubbles, considered consistent with food.
• The computed tomographic attenuation of this material varied widely within and between different cases.
• In a majority of the cases (16 out of 17), concurrent dental diseases were found in addition to the fistulae.

Implication of the findings

• Although the main diagnostic method remains the identification of feed materials in the sinus or nasal passages, the study supports the use of CT as an additional test.
• More specifically, CT can offer value in determining disease extent and in planning surgical approaches, especially considering the high incidence of concurrent dental conditions.