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An Urban Experience
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 diastema. If the tooth is already absent, the incisions are made at the mesial and distal edges of the fistula.
When making flap incisions, adequate pressure should be placed to ensure full thickness of the soft tissue is incised down to the bone. Any vertical incisions should be created slightly divergent as they proceed apically. Divergent incisions allow for adequate blood supply for the newly created pedicle flap. It is important to choose the location of the incisions to ensure that sutured margins will have adequate bony support and will not lie over a defect.
The mucogingival flap is gently elevated off the bone using a periosteal elevator.
Approximately 2-3mm of palatal mucosa is also gently elevated/lifted off the palatal bone so that fresh epithelial edges are created. Any margins of the flap associated with the oronasal fistula should be debrided using a LaGrange scissors or coarse diamond bur to remove 1-2mm of tissue, leaving fresh epithelial edges.
A coarse diamond bur on a high-speed handpiece is used to smooth the edges of the remaining maxillary bone (if necessary) and to remove any epithelial remnants between the fistula and the nasal cavity.
As with any closure in the oral cavity, the key to success is to ensure there is no tension on the incision line. Fenestration of the inelastic periosteum (see previous section on surgical extractions) is performed to increase the mobility of the flap and allow for a tension free closure. This is accomplished by a combination of sharp and blunt dissection with a LaGrange scissors to ensure the overlying mucosa is not damaged.
The gingival flap is then placed over the defect so that
it remains in position without being held. Once this is accomplished (i.e. no tension is present), the flap is ready to be sutured into place.
Further reading: Niemiec BA: Dental Extractions Made Easier. Practical Veterinary Publishing. Tustin CA www.

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