Radiographic identification of the equine dorsal and ventral nasal conchal bullae

Radiographic anatomy of the nasal conchal bullae and conchal sinuses in mature horses

The dorsal and ventral nasal conchal bullae and conchal sinuses are part of the complex equine paranasal sinus system and are commonly affected by secondary sinusitis. However, the radiographic anatomy of the conchal sinuses is poorly reported in the literature. The present study aimed to describe the radiographic anatomical characteristics of the nasal conchal bullae and conchal sinuses in mature horses. Six equine cadaveric heads without sinus or dental disorders were studied. A maxillary sinusotomy was performed to identify the dorsal and ventral nasal conchal bullae and conchal sinuses, allowing the application of radiopaque contrast medium in these structures. Afterward, the same projections were repeated. Laterolateral views allowed an adequate visualization of nasal conchal bullae and conchal sinuses; however, they overlapped the same contralateral structure. In the latero30°dorsal- lateroventral oblique view, the same structures were easily recognizable, but in an oblique view, the structures were projected dorsally in relation to the contralateral one. The dorsoventral view allowed partial visualization of the dorsal conchal bullae and dorsal sinuses, but it was not possible to identify the ventral conchal sinus and ventral conchal bullae. The offset dorsoventral view helped in the identification of the dorsal conchal bullae and dorsal conchal sinus, also achieving visualization of the medial region of the ventral conchal sinus and ventral conchal bullae. The use of contrast medium, added to the anatomical dissection, allowed a better radiographic identification of the sinuses and conchal bullae. The combination of different radiographic views is recommended for the evaluation of these structures.

Radiographic characterization of the maxillary septum and septal bullae in horses: An ex vivo study

The anatomical variations of the maxillary septum and the septal bullae can generate challenges during the interpretation of radiographs of the horses' heads and make it difficult to accurately identify the sites affected in sinus disorders. The description of the radiographic appearance of these structures is currently scarce in the scientific literature. This work aims to describe the anatomical and radiographic characteristics of the maxillary septum and maxillary septal bullae in horses. Six chemically preserved equine cadaver heads were used which, after being submitted to the maxillary osseous flap, the maxillary septum and its respective bullae were identified. Radiographic examinations before and after contrast impregnation on these structures were performed. The positioning of the maxillary septum varied between the anatomical specimens and between the sides of the same specimen. The 30° oblique dorsoventral lateral and lateral projections allowed the identification of the maxillary septum and septal bullae. However, the bullae remained superimposed on the dental arches in the dorsoventral projections with the mandible in a neutral position or with the mandible displaced. The oblique offset radiographic positioning was suggested and proved effective for the examination of the maxillary septal bullae, where the mandible was displaced to the side of the bullae to be examined, and the radiographic beam inclined in the same direction. The maxillary septum and its bullae could be properly identified in a macroscopic way after the osseous flap and the contrasted radiographic examination allowed its adequate interpretation. Variations in size and position are considered normal for the equine species.

An anatomical study of the dorsal and ventral nasal conchal bullae and middle nasal conchae in normal Shetland ponies: Computed tomographic anatomical and morphometric findings

Equine paranasal sinuses are susceptible to inflammation. Insufficient drainage through the nasal passages and meatus may lead to the accumulation of inspissated purulent discharge. Particularly in ponies, these anatomical structures are suspected to be relatively small. To date, there are no reports considering the morphology of nasal conchal bullae in small horse breeds such as Shetland ponies. The aim of the present study was to evaluate the size of the conchal bullae and the medial nasal conchae of Shetland ponies and their relation to the skull dimension using computed tomography. Reconstructed images of healthy adult heads of Shetland ponies were used. Linear skull measurements as well as two cranial indices of the head dimensions were taken. Length, width and height of the dorsal and ventral conchal bullae and the medial nasal conchae were measured in relation to the skull and compared with the data of skulls of large breed horses. The anatomical proportions of pony heads were characterized by a smaller cranial index and a greater nasal index than those of large breed horses. Shetland ponies showed a longer cranial length compared with the nasal length. Heads are consistently smaller, and the relationship of the bullae to the head length was also smaller than those measured in large breed horses. A negative correlation between the head and bullae size was found. In conclusion, this study suggests that Shetland ponies have distinguishing proportions of the head. These findings are relevant for clinical examination and surgical treatment of equine sinus disease in those breeds.

Computed Tomographic Assessment of Individual Paranasal Sinus Compartment and Nasal Conchal Bulla Involvement in 300 Cases of Equine Sinonasal Disease

Background: Computed tomographic (CT) imaging has allowed new anatomical studies and detailed clinical imaging of the complex, overlapping equine sinonasal structures. Despite the widespread use of CT, no study has specifically identified which compartments are most commonly affected with sinus disorders. CT has also shown the presence of intercurrent, ipsilateral nasal disorders, especially infection of the nasal conchal bullae (NCB) in many cases of sinus disease, but the frequency of intercurrent NCB infections has not been reported.

Objectives: To identify which sinus compartments are most commonly affected in horses with clinical sinus disorders and to record the prevalence of NCB involvement in such cases.

Study Design: Retrospective examination of CT images of horses with confirmed unilateral sinus disease.

Methods: The CT images of 300 horses, from three different equine hospitals with clinically confirmed sinus disease [mainly dental (53%) and primary sinusitis (25.7%)] were retrospectively examined to determine which sinus compartments and NCBs were affected.

Results: The rostral, more dependent sinus compartments were most commonly involved, i.e., the rostral maxillary sinus in 284/300 (94.7% affected) and the ventral conchal sinus (87% affected). The caudal maxillary sinus (65.3%), dorsal conchal sinus (52.7%), frontal sinus (26%), ethmoidal sinus (32%) and sphenopalatine sinus (28.7%) were less commonly affected. There was infection or destruction of the ipsilateral NCBs in 56% of horses with sinus disorders, including the ventral NCBs in 42.3%, dorsal NCBs in 29% and both NCBs in 18% of cases.

Main Limitations: The horses with sinonasal disease that underwent head CT imaging include more problematic cases and horses of high value, rather than the general horse population.

Conclusions: The more dependant (i.e., the RMS and VCS) sinus compartments are most commonly involved in sinus disorders, with the RMS involved in nearly every case. The more dorsally located sinuses (i.e., caudal group) are less commonly involved. Many horses with sinus disease also have disorders of their nasal conchal bullae and so the term sinonasal disease seems appropriate for these disorders.

Equine Nasal Endoscopy: Treating Bullae Disease and Sinus Disease

The nasal conchal bullae (dorsal and ventral) are separate, air-filled structures within their respective dorsal and ventral nasal conchae. Computed tomography scans have assisted with the increasing diagnosis of empyema of the nasal conchae. This condition is usually associated with dental or sinus disease. Drainage of affected bullae is considered critical for resolution of clinical signs. The ventral conchal bullae can be easily viewed with a standard 10 mm diameter flexible endoscopy via the middle nasal meatus. This approach can also be used for fenestration of the bullae, using a diode laser, equine laryngeal forceps, or bipolar vessel sealing device.