The phrase “It’s like pulling teeth” arose for good reason.
It’s one thing to extract a tooth with severe periodontal disease that is barely attached to its surrounding structures, and entirely different to extract firmly rooted teeth. Consider the analogy of an archaeologist working at a dig to successfully remove ancient fossils and intact artifacts.
Many indications exist for extraction of a firmly rooted tooth, including endodontic disease, tooth resorption, and crowding of persistent deciduous and permanent teeth. Though extractions occur daily in nearly every practice, many practitioners have not been taught how to effectively and efficiently extract firmly rooted teeth. Here are 20 steps to perfect extraction of firmly rooted teeth.
Wash the mouth with diluted chlorhexidine oral rinse (0.12 percent)
This step protects the operator and the patient by decreasing aerosolization
of bacteria during the procedure and lowering the bacterial burden at the surgical site.
Perform a regional nerve block
Extraction of firmly rooted teeth is painful because of the need to raise a mucoperiosteal flap and remove bone. A long-acting local anesthetic such as bupivacaine provides intraoperative pain relief and up to 10 hours of postoperative pain relief.
Take a preoperative radiograph
Variation exists in root structure and periodontal anatomy. Dental radiographs allow for creation of an individual treatment plan. Also, radiography finds pathology not visible on oral examination. Since replacement resorption is common in cats, it is impossible to decide on an appropriate approach to extraction of a feline tooth without a preoperative dental radiograph.
Ensure a protected airway
The cuff of the endotracheal tube should be leak-free but not overfilled. Place a laparotomy sponge in the caudal pharynx. The long string attached to the sponge will act as a reminder to remove it at the end of the procedure, unlike a gauze square that might be easily forgotten in the back of the throat.
During the procedure, position the patient’s head so the tip of the nose is slightly ventral to caudal pharynx.
Raise a flap
Flaps come in different shapes and sizes, and the key to efficient extraction is choosing the proper flap. An envelope flap is the most basic, with an incision in the gingival sulcus that completely separates the attached gingiva around the entire circumference of the tooth. The envelope flap has the benefit of being least invasive, but since it involves no releasing incisions, this flap is not chosen when visualization and bone removal are necessary for successful root removal.
A triangle flap has one releasing incision and is a good choice for two-rooted teeth where one root suffers from severe periodontal disease and one is firmly rooted. In this case, the releasing incision would be made to increase exposure to the firmly rooted portion of the tooth.
A pedicle flap involves divergent releasing incisions at each edge of the flap. This flap provides the most expo-sure. When all teeth in a quad-rant require extraction, such as in treatment of feline stomatitis, creation of one large flap is more efficient than multiple small flaps. A periosteal elevator is used to raise the gingiva and mucosa, with care to avoid perforation of the flap at the mucogingival junction.
If a triangle or pedicle flap is raised, separate the periosteum
Blunt and sharp dissection of the periosteum from beneath the flap is accomplished by inserting a closed pair of Metzenbaum scissors (for small flaps, a 5-inch pair of curved Ragnell scissors works well) into the space between the mucosa and the periosteum at the edge of the releasing incision at the base of the flap.
Once placed, the scissors may be opened to stretch the periosteum and separate it from the mucosa. The perio-steum is transparent and may be bluntly or sharply dissected from the mucosa to mobilize large amounts of tension-free mucosa. This step is done prior to extraction to ensure adequate visualiza-tion and allow for rapid closure once the tooth is removed. A stay suture is placed to reflect the flap with minimal trauma.
Remove a window of bone from the buccal (vestibular) surface of the root
Use a round carbide bur (size 1, 2 or 4) on a high-speed, water-cooled handpiece to create a window in alveolar bone over buccal root surfaces. About 60 percent of bone is removed, and if the tooth shows no signs of movement during elevation, more bone may be removed in the direction of the root tip (apically). Take care when using burs in the apical area to avoid bleeding and damage to neurovascular structures near the apex of the tooth roots.
Use a quarter-inch round carbide bur to further expose the root structure
After bulk removal of vestibular bone with a size 1, 2 or 4 carbide bur, the root can be further excavated and the true outline of the root discerned with the light touch of a high-speed handpiece equipped with a quarter-inch round bur.
Use a 701 or 702 surgical carbide bur to section multirooted teeth
The 701 is a crosscut fissure bur that sections multirooted teeth into separated one-rooted tooth/crown segments. The 702 is thicker and less likely to break when sectioning larger teeth (such as carnassials in dogs). Surgical burs are 7 mm longer than non-surgical burs. The bur must extend slightly into furcational bone to ensure complete separation of one root from another.
Ensure that the roots of multi-rooted teeth are separated
Insert a dental elevator into the space created by the 701 or 702 bur to observe whether subtle movement is visible when leveraging the elevator between separated crown/root segments.
Begin elevating the tooth
Place a winged dental elevator along the long axis of the root in between the separated crown segments of the multi-rooted tooth to begin to loosen both roots simultaneously. Continue to elevate along the long axis of each root with an appropriately sized elevator to separate the periodontal ligament.
Place the elevator within the periodontal space, twist to generate slight movement of the root, and hold for 10 seconds. Twist and hold in the opposite direction for 10 seconds. As periodontal ligament fibers become stretched, elevators can be placed farther down the root toward the apex. Smaller elevators are more likely to fit in the periodontal ligament space and less likely to accidentally fracture the root.
If a root breaks off during elevation, remove more bone from the buccal surface and use a round bur to carefully create a moat around the remaining root
Use a smaller dental elevator or root tip elevator to pry the root through the buccal window. Avoid generating forces in the apical direction so the root isn’t displaced into the mandibular canal or nasal passage.
Use extraction forceps
Once the root is “piano key loose,” use extraction forceps to grasp the crown/root segment. Twist and hold in one direction for 10 seconds, in the other direction for 10 seconds, then gently pull. For fractured tooth roots, use diamond-coated root-tip forceps to grasp small roots.
Debride and lavage sockets
Use a bone curette to debride the socket and flush with 0.12 percent chlorhexidine, 0.9 percent saline or lactated Ringer’s solution.
Elevate soft tissue
Use a periosteal elevator to raise soft tissue on the lingual or palatal side of the exposed bone. This allows for easier suture placement.
Prepare the flap edge for closure
Trim tattered edges of the flap with Metzenbaum or Ragnell scissors.
Remove sharp bone edges
Use a large round diamond bur (No. 29) to smooth sharp edges of alveolar bone before flap closure.
Take a postoperative radiograph
This step provides assurance of a job well done and documentation in cases of postoperative complications.
Suture the extraction site
Closure allows for more rapid healing and prevents food and hair from accumulating in the site. Even extraction sites of overtly infected teeth can and should be closed after thorough debridement and lavage.
Close the flap starting with a suture at the gingival margin at the corner of a releasing incision using 4-0 (medium and large dogs) or 5-0 (cats and small dogs) absorbable monofilament on a tapered needle, simple interrupted pattern, about 3 mm apart.
Inspect the oral cavity
Remove the laparotomy sponge and inspect the pharynx.
With the right tools and knowledge, extraction of firmly-rooted teeth can be transformed from a dreaded task to a satisfying part of veterinary practice.
Dr. Lewis, FAVD, Dipl. AVDC, is an assistant professor of dentistry and oral surgery at the University of Pennsylvania’s School of Veterinary Medicine.