We decided to make a small opening through the maxilla to gain access to the infected area for a thorough cleanup of the area. Also, we needed to evaluate the communication of the drain tract to the nasal cavity. Extraction of the 107 without removing the necrotic tissue and tooth fragments may not resolve the infection. Drainage of the abscess is established when the tooth is extracted, but the necrotic tissue and fragments may act as sequestra which will produce a chronic drain tract into the oral cavity. Aggressive debridement of these large abscesses may avoid a second surgery in the future.
Discussion:There are two main points to this article. The first is that an abscess takes the path of least resistance, which in this case was into the nasal cavity. This is not common because the flat bone of the maxilla is usually thin, but during the body’s walling off process of the abscess, the bone became thick and sclerotic on the outside of the maxilla before the abscess ruptured, which forced it to drain medially into the nasal cavity. Secondly, the oral extraction and the modified trephination surgery were performed on a standing horse with sedation and local anesthesia. The advantages of a standing procedure are increased hemostasis because the head is in an elevated position, comfort and good orientation for the oral practitioner, elimination of general anesthesia and possible complications, no recovery time, and more time to complete the procedure. Also, these procedures can be done in any clean environment, without a surgery suite or recovery room. Economically this favors the horse owner, and hopefully will encourage more advanced dental procedures to be used in the equine industry.