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 25-28 September, 2018 | Singapore
is to allow sufficient exposure for bone removal, as the root curves back to over the second premolar.
If a mesial incision is performed, it should be in
the diastema between the canine and third incisor. Classically it was made at the line angle of the canine
or third incisor. However, in this author’s opinion, the mesial line angle of the canine does not allow sufficient exposure and there is no reason to risk damaging the third incisor and increase surgical trauma. It is critical to fully incise the interdental gingiva to avoid tearing the flap. This is particularly challenging in the area mesial
to the canine. Make sure to cut all the way to the bone. Following the creation of the vertical incisions, the flap is carefully elevated. If it is not elevating fairly easily, ensure that the interdental tissue is fully incised.
Once the flap is raised, approximately 1⁄2 of the buccal bone is removed. Make sure to remove some of the mesial and distal bone as the tooth widens just under the alveolar margin.
After the bone removal, elevate the tooth carefully. Do not torque the crown too much bucally as this will lever the apex into the nasal cavity. Once the tooth is elevated to a point of being very loose, it can be carefully extracted with forceps. The bone is then smoothed with a coarse diamond bur.
Closure is initiated with fenestration of the periosteum. When this is performed the tissue should stay in position over the defect. If it does not, tension is present and
the flap will dehisce. It is critically important to relieve all tension if an oronasal fistula is present. Close the flap starting at the corners to avoid having to start over if it does not close correctly. Mandibular canine
These are quite simply the most difficult extraction in veterinary dentistry. This is due to the length and curve of the root, the hardness of the mandible, and the minimal bone near the apex. Furthermore, extraction
of this tooth will greatly weaken the jaw and further predispose the patient to an iatrogenic fracture either during or after surgery. This tooth often holds the tongue in, and therefore it is not uncommon for the tongue to hang out following the extraction. Finally, the patient loses the function of the tooth. Therefore, it is strongly recommended to avoid extraction of this tooth. Referral for root canal therapy is a much better solution, if possible.
Some authors recommend a lingual approach to this extraction since less bone needs to be removed as to tooth curves lingual apically. However, this author prefers the standard buccal approach. This is because superior exposure is afforded and the flexible buccal mucosa allows for easier closure.
The flap for this extraction is generally triangular with just one distal vertical flap. A horizontal incision is created
along the arcade to the mesial line angle of the first premolar. Then a distally divergent vertical incision is created. Next, the flap is carefully elevated and the buccal bone is removed to a point about 1/3 of the way down the root. More bone can be removed if necessary, but be careful with creating a larger flap or taking more bone as the mental nerve and artery exit approximately 3/4 of the way down the root. The tooth is then carefully elevated and extracted. Debridement and closure is as above.
Extraction of retained roots
Root fracture is a very common problem in veterinary dentistry. While it seems that removal of retained root tips is a daunting task, with proper technique and training it can be fairly straightforward. The first step is to create a gingival flap. Depending on the anticipated amount of exposure necessary to retrieve the fragments, this can either be an envelope flap or a full flap with one or two vertical releasing incisions.
Following flap creation, buccal cortical bone is removed with a carbide bur to a point somewhat below the most coronal aspect of the remaining root. If necessary, the bone can be removed 360 degrees around the tooth, but this author tries to avoid this aggressive approach.
Once the root(s) can be visualized, careful elevation with small, sharp elevators is initiated. Once the tooth is mobile, it can be extracted normally. After radiographic confirmation that the tooth is fully extracted, the bone is smoothed and the defect closed.
Oronasal fistula repair
In most cases, the single layer mucogingival flap technique is sufficient to repair ONFs, especially when done correctly the first time. This is the most common surgical treatment used to repair ONFs and therefore will be presented here.
The single layer mucogingival flap is created with either one or two vertical incisions. Depending on the size and location of the fistula as well as presence of the offending tooth, a horizontal interdental incision may also be necessary for successful repair. Proper design of the mucogingival flap will allow maximum exposure of the area for extraction of the tooth (if necessary), debridement of the fistula, and critically important tension-free closure.
Incisions are created with a number 15 or 11 scalpel blade. As described previously, the vertical incision(s) were classically started at the line angle of the teeth. A line angle is a theoretic corner of a tooth. When repairing an ONF associated with a maxillary canine tooth, the distal incision is made at the mesial line angle of the
first premolar, and the mesial incision is started at the mesial line angle of the canine (if present). However, it is not necessary to cut over to a line angle if there is a

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