In this article, we will discuss feline surgical extractions, including tips and tricks that will make your next feline dental extraction easier.
Flaps Are Our Friends!
When I speak with general practitioners about extraction of firmly rooted feline teeth, sometimes they will begin the conversation with a confession: “We don’t do flaps here.” To this I will pose an analogy. Trying to extract large, firmly rooted feline premolar, molar or canine teeth without a flap is analogous to trying to catch a football with one arm tied behind your back. It can be done, but not reliably, and not without much frustration.
For our discussion today, let’s use the scenario of a feline patient whose right mandibular cheek teeth need to be extracted [third premolar (407), fourth premolar (408) and first molar (409) teeth].
This raises an important point about extraction of adjacent teeth. If you identify a tooth that needs to be extracted, assess the adjacent teeth to determine if these teeth also need to be extracted. If so, rather than raising multiple flaps for each individual tooth, a single flap can be raised to extract multiple teeth.
John r. Lewis
Figure 1: Surgical extraction of teeth 407, 408 and 409. A flap has been raised, and a stay suture allows for atraumatic retraction of the flap.
For our example of extraction of teeth 407-409, a single flap is raised, starting with a releasing incision just caudal to the labial frenulum. The labial frenulum is the triangular raised tissue that sits between the crown of the canine tooth and the crown of the mandibular third premolar tooth in cats.
The releasing incision is started with a #15 scalpel blade at the most mesial (front) aspect of the gingiva of the third premolar and is continued ventrally for approximately 8 millimeters. The tip of the scalpel blade is then inserted into the sulcus of tooth 407 from the releasing incision caudally and extended into the sulcus of lateral 408 and 409.
The incision is finished approximately 5 mm caudal to the caudal aspect of the crown of tooth 409. A releasing incision may not be necessary caudal to tooth 409 but can be done if necessary.
The flap is carefully raised with a small periosteal elevator, and a suture may be placed to reflect the flap without trauma.
Use The Drill
Now that a flap is raised, use a high speed dental drill with a #2 carbide bur to remove a window of bone over the roots of all teeth being extracted (Figure 1). How much of the root should be exposed? I usually expose 60-70 percent of length of the root to allow for minimal force to pry the crown-root segments from the windows created.
Once the windows have been created and the furcations slightly exposed with the #2 bur, use a #701 crosscut fissure bur to section the multi-rooted teeth into single-rooted crown-root segments.
John r. lewis
Figure 2: Moats are created around multiple roots, which allow an elevator to be placed on the lingual side of the root to pry the root in a lateral direction from its socket.
A few notes about this portion:
- To fully separate the roots from each other, the bur usually needs to go slightly deeper into the furcation than you might expect.
- The furcations of teeth 407 and 408 are where you’d expect them to be, but the furcation of tooth 409 is caudal to the midpoint of the crown. The mesial (front) root is larger than the distal (back) root.
- Always wear eye protection when using burs, especially thin crosscut fissure burs.
Patience, Patience, Patience
Once the teeth are sectioned and the windows are created, we are ready to elevate the crown root segments from their sockets. Cat teeth are designed to stay seated in their sockets: millions of periodontal ligament fibers (Sharpey’s fibers) are preventing you from simply “pulling” the tooth, and these fibers need to be fatigued, stretched and torn to allow for delivery of the tooth.
John r. lewis
Figure 3: Root tip forceps are used to remove a stubborn root after the root has been elevated to the point of being very mobile.
For teeth 407-409, I use a winged dental elevator 2 mm in width. I will begin elevation by placing the winged elevator into the space created by sectioning of the multi-rooted teeth. This allows for weakening of the periodontal ligament on the distal surface of the mesial root and the mesial surface of the distal root.
Once I see some progress from elevating in this area, I will move to another spot, usually the distolingual or the mesiolingual surface of the crown root segments. The winged elevator is seated into the periodontal ligament space and gently twisted so a wing of the elevator pushes the crown-root segment out of the window on the lateral surface of the root.
A few notes on this portion of the procedure:
- Be patient. With time you will get a feel for how much force is too much when rotating the wings of the elevator.
- Controlled force is the key. Except for the initial seating of the elevator in the periodontal ligament space, force is not being directed in an apical direction; the force is being created by a gentle twist of the wrist.
- Always keep your index finger extended down the shaft of the elevator so if your elevator does slip, your index finger will catch on something hopefully before any significant sublingual trauma occurs.
- If you hear the dreaded “crack” of the crown-root segment as you elevate, don’t fret. Think of this as an opportunity to remove the pesky crown so you can see the remaining root better.
Break A Root, Make A Moat
Even the best veterinary dentists have roots break during extractions. Some reasons include ankylosis (fusion of the root to surrounding bone) and hypercementosis (the reason for those challenging “bulbs” on the tip of the root), usually in geriatric patients.
John r. Lewis
Figure 4: The flap is closed with a simple interrupted pattern of absorbable 5-0 suture spaced at approximately 3 mm apart.
When you need to retrieve a root tip, reach for your high-speed drill. Rather than using the drill to pulverize the root (and possibly adjacent neurovascular structures) to oblivion, use a moat technique. A surgical length ½ round carbide bur can be used to enlarge the window on the lateral surface of the remaining root, and a 2 mm deep moat is created around the circumference of the root to allow for a small elevator to be placed on the lingual surface of the root to pry the root from its newly created lateral window.
After all roots are removed, the sharp edges of bone are smoothed with a #23 round diamond bur, a dental radiograph is taken, and the site is closed with a simple interrupted suture pattern, spaced 3 mm apart, with 5-0 absorbable suture such as poliglecaprone 25.
Hopefully these tips will demystify the somewhat daunting task of feline extractions. I encourage you to enroll in a wet lab since nothing beats a well-supervised, hands-on experience.