Levator Labii Superioris Muscle Transposition to Treat Oromaxillary Sinus Fistula in Three Horses

Abstract

To describe surgical transposition of the levator labii superioris muscle to treat oromaxillary sinus fistula in horses. Clinical study. Three horses with chronic oromaxillary sinus fistula. After severing its tendinous insertion, the muscle belly of the levator labii superioris muscle was retracted and transposed through the oromaxillary sinus fistula. The tendon exited the oral cavity through a full-thickness buccal incision created adjacent to the oral end of the fistula and was then tunneled subcutaneously in a ventral direction before being anchored by sutures to the cheek tissues. Fistulae healed with few complications and with good cosmetic and functional results. Oromaxillary sinus fistula associated with molariform tooth loss in horses can be treated successfully by transposition of the levator labii superioris muscle. Transposition of the levator labii superioris muscle should be considered for resolution of chronic oromaxillary sinus fistula in horses.