How to Perform Levator Labii Superioris Muscle Transposition to Treat Oromaxillary Sinus Fistulae in Horses

摘要

Oromaxillary sinus fistula formation is a reported complication after loss or removal of the caudal four maxillary teeth in horses, occurring in 7—33% of cases. Repulsion of sinus-associated cheek tooth in horses creates communication between the oral cavity and paranasal sinuses. Typically, the oral aspect of vacant alveolus is temporarily protected until the alveolus fills with granulation tissue to prevent fistula formation. Overfilling the alveolus so that the temporary alveolar plug extends into the sinus can result in fistula formation because the alveolus becomes epithelialized, preventing granulation tissue closure when the plug is removed or lost. This can occur more easily in older horses because of the relatively short length of their alveoli. Other causes of fistula formation are inadequate seal of the alveolus, early loss of the temporary alveolar plug, incomplete removal of dental tissue, development of osseous sequestra, or residual infection.