case_images: PMC10904605_01
case_images: Note the obvious large mid-facial defect (B) accompanied by smaller defects (A) and (C) ventral to both eyes. All lesions were actively draining with mucopurulent and crusted discharge. Incidental findings of marked anisocoria and heterochromia iridum.
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case_images: PMC10904605_01_fvets-11-1343039-g001.jpg
case_images: fig1
case_images: There were four additional cutaneous draining tracts noted approximately 4 x 4 mm ventral to the left eye, to the lateral side of the right eye, between the eyes, and on the medial aspect of the right eye (Figure 1).
case_images: Large oronasal fistulas (A) were repaired at a second stage procedure. A large mucoperiosteal flap was elevated and manipulated using stay sutures (B). Note that the infraorbital neurovascular bundle was left intact to preserve blood supply. After removing the epithelial lining of the fistulas, tension-free closure was achieved with single interrupted resorbable sutures (C). A 6 months follow-up revealed excellent healing (D).
case_images: fvets-11-1343039-g002.jpg
case_images: PMC10904605_01_fvets-11-1343039-g002.jpg
case_images: fig2
case_images: An intraoral examination revealed an oronasal fistula extending from the right maxillary canine tooth to the right maxillary fourth premolar tooth (Figure 2A).
case_images: Panels (A-C) represent pre-operative CT, three-dimensional (3D) reconstruction (A,B), and a transverse plane at the level of the fourth premolar tooth (C) images. Panels (D-F) represent 6 months postoperative CT, 3D reconstruction (D,E), and a transverse plane at the level of the fourth premolar tooth (F) images. The large bone defects in the frontal, maxillary, and nasal bones (A-C) have reduced in size (D-F) after successful reconstruction, as demonstrated by the measurements provided in panels (C) and (F).
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case_images: PMC10904605_01_fvets-11-1343039-g003.jpg
case_images: fig3
case_images: Computed tomographic findings included multifocal to coalescing lucent osseous lesions predominantly affecting the cortical bone of the right rostral maxilla (Figures 3A,B). There was a resultant large draining tract affecting the nasal, frontal, and maxillary bones that communicated with the cutaneous surface (Figure 3C).
case_images: (A-E) Photomicrographs of tissue submitted for histopathological evaluation. (A):20x magnification of the section of the bone with associated respiratory epithelium (presumes sinus lining). The subepithelial tissue is markedly altered and thickened by edema, fibrin exudation, and inflammatory cellular infiltration (asterisk). (B):100x magnification of the tissue adjacent to the bone spicule. The inflammatory infiltrate comprises lymphocytes and plasma cells (black oval). In addition, the resorption lacuna occupied by osteoclast is shown (black arrowhead), indicative of bone resorption/modeling. (C):400x magnification of the inflammatory infiltrate shown in (B). (D):100x magnification of an exudate composed of protein-rich (hot pink background) fluid suspending hundreds of polymorphonuclear cells (neutrophils primarily) and bacterial colonies (white ovals). (E):400x magnification of bacterial cocci colonies shown in (D).
case_images: fvets-11-1343039-g004.jpg
case_images: PMC10904605_01_fvets-11-1343039-g004.jpg
case_images: fig4
case_images: The biopsy sample submitted for histopathological evaluation consisted of exudate with crust and an osseous fragment associated with soft tissue (Figure 4). The bone tissue was a fragment of lamellar bone (mature bone) rimmed multifocally by woven bone (immature bone) (Figure 4A). Multifocally resorption lacunae occupied by multinucleated osteoclasts were noted in the absence of osteoblasts, indicative of bone remodeling (Figure 4B). The crust and exudate suspended large numbers of intact and degenerate neutrophils admixed with bacterial cocci colonies and birefringent foreign material resembling plant and pollen (Figures 4C-E). This fibrous connective tissue was lined by primarily pseudostratified columnar ciliated epithelium that was multifocally substituted by squamous epithelial lining, indicative of squamous metaplasia (Figure 4).