Successful treatment of an equine orosinus fistula using a titanium screw

Summary This case report outlines the long‐term successful treatment of a non‐healing orosinus fistula with placement of a 16‐mm diameter titanium screw within the compromised alveolus. A 7‐year‐old mare presented for investigation of a 2‐month long chronic right‐sided sinusitis, which had been unresponsive to several courses of broad‐spectrum antimicrobials. The mare was reported to head toss under ridden exercise. Malodorous purulent right‐sided nasal discharge was noted with ipsilateral submandibular lymphadenomegaly. There was diffuse right‐sided frontonasal facial bone swelling and epiphora present. The horse underwent computed tomography where it revealed marked periapical changes of cheek tooth 110 with discontinuity of the alveolar bone suggestive of an orosinus fistula. 109 had endodontic changes consistent with gas contained within the pulp horns. Cheek tooth 110 was extracted orally and oral endoscopy revealed a buccal alveolar wall defect. The fistula measured 2 × 1cm and communicated with the maxillary sinus which was seen on sinoscopy. On repeat CT 2 months later, the orosinus fistula was persistent, 109 had deteriorated and was extracted orally. A 16‐mm diameter, 24‐mm long self‐tapping titanium screw was placed into the fistula subocclusally using a Torx screwdriver handle and shaft. Sinus lavage was performed with no leakage at the plugged 110 site and the screw was still in place 7 days later. The mare represented 3 months later for a follow‐up appointment. On CT and oral endoscopy, the titanium screw was now absent; however, the orosinus fistula was completely healed with no communication present and resolution of clinical signs.