Management of an Oronasal Fistula Using Microscope-Assisted Er:YAG Laser Periodontal Regenerative Therapy in a Dog.

Oronasal fistula formation, associated with maxillary canine teeth, is a frequent sequela to untreated periodontal disease, and extraction has traditionally been regarded as the primary treatment. A 10-year-old spayed female miniature Dachshund was presented with an oronasal fistula involving the left maxillary canine tooth. After initial non-surgical management with minimally invasive non-surgical technique (MINST) failed to resolve the periodontal pocket and fistula, microscope-assisted periodontal regenerative therapy combined with an Er:YAG laser was performed. The treatment achieved complete closure of the fistula together with reduction of the periodontal pocket. Cone beam computed tomography at 8 months post-surgery confirmed new bone formation. This case demonstrates that the integration of microsurgical visualization and Er:YAG laser therapy can enable preservation of maxillary canine teeth with oronasal fistula, providing a minimally invasive alternative to extraction.