Sessions

Treatment of oral fistulas in horses is often a lengthy and complex process for both the owner and the veterinarian. Oro-nasal and oro-sinusal fistulas typically develop in locations that are difficult to access therapeutically, which is why conventional surgical procedures often fail. As a result, healing may become so delayed that treatment can extend over several years. The aim of the procedure we developed is to treat oro-nasal and oro-sinusal fistulas in which healing has stalled, by utilizing the body’s own regenerative resources. In our study, we present 16 cases of horses treated with the implantation of an autologous iIT biological membrane into the alveolus, and we monitored their healing. The platelet- and leukocyte-rich biological membrane contains numerous bioactive substances that promote healing, and its effect is further enhanced by its persistence in the alveolus for up to 2–3 weeks, allowing for a prolonged therapeutic action. We hypothesize that implantation of the material into the alveolus shortens healing time, reinitiates regeneration in fistulas where healing has failed, and reduces treatment costs. Our research was conducted at the Department and Clinic of Equine Medicine, University of Veterinary Medicine Budapest. In horses diagnosed with oro-nasal or oro-sinusal fistulas, the fistula cavity was filled with the iIT membrane. Prior to implantation, the affected area was always surgically exposed to remove infected tissues. In cases involving the paranasal sinus system (oro-sinusal fistulas), trepanation was performed, enabling irrigation of both the fistula and the sinus system from within. In oro-nasal fistulas, surgical curettage of the affected area was performed via the oral cavity. Impressions of the alveolus forming the fistula site and of the adjacent teeth were taken using dental silicone paste, and based on these impressions, a custom-made implant was manufactured with the aim of sealing the fistula from the oral side. This implant was fabricated by a dental laboratory using a 3D printer. Upon arrival, the implant was placed and sealed with a two-component silicone filler to ensure a watertight closure, which was secured by the metal implant at the entrance of the alveolus. Of the horses studied, in eight cases the fistula had persisted for more than six months, while in the other eight it had been present for a shorter period. According to our results, with the procedure we developed, complete healing was achieved within six months in nine cases, whereas during the initial phase of method development, symptom resolution and alveolus closure typically occurred between 9 months and 1 year. In some cases, healing time was influenced by circumstances beyond our control (e.g., change of ownership, immobility due to foaling). With regard to the use of the titanium implant, we observed that in addition to covering the alveolus, it was also suitable for preventing possible tooth displacement caused by missing teeth.