How Can You Tell If Your Cat Has Dental Disease?

One of the most commonly performed oral surgery procedures in general practice is exodontia, or Tooth extraction. Indications for extraction, grouped by patient age, are shown in BOX 1. Your objective with extraction is to remove the entire tooth and root without unnecessary damage to the surrounding soft tissue or bone. The easiest way to avoid surgical complications is through adequate preparation. Completing extractions in a consistent, orderly manner will decrease the incidence of complications.

EXTRACTION BASICS

When oral surgery is performed to remove teeth, controlled forces and proper technique—including use of a short finger stop (FIGURE 1)—are essential. Before attempting to elevate the tooth roots, section all multirooted teeth, and for open extractions, remove adequate buccal bone to visualize the tooth root. Visualization is crucial for successful surgical extractions. The tooth is held in the alveolus by the periodontal ligament. The key to tooth removal is stretching and breaking down the periodontal ligament by placing the dental elevator into the periodontal ligament space and using slow rotational pressure to fatigue the periodontal ligament.

After tooth removal, always inspect the extracted root to be sure the apex is smooth and round. A rough or jagged root edge indicates the probability of a root remnant remaining in the alveolus. Always take postoperative radiographs to document complete extraction of the entire tooth root without unnecessary damage to the surrounding bone. The following list provides tips and guidelines to help you avoid complications when extracting teeth. See also BOX 2.

• Always consider your skill and knowledge. If a procedure is beyond your capability based on your knowledge, skill, and/or the pathology that is present, it is best to refer the patient to a board-certified veterinary dentist.
• Understand basic anatomy, including tooth anatomy, location of neurovascular bundles, the mandibular canal, nasal cavity, and the orbit. This knowledge is critical for avoiding key structures during extractions.
• Always take preoperative intraoral radiographs. Preoperative radiographs enable you to carefully evaluate the entire tooth, the periapical area, and the surrounding bone (FIGURE 2), as well as to formulate a treatment plan.

• Consider all information. Combine what you see clinically, what you see radiographically, and clients’ commitment to their pet’s oral healthcare to make an appropriate treatment decision about each tooth.
• Use preemptive multimodal pain management to provide oral surgery patients with a more comfortable intraoperative and postoperative period. Use of intraoral regional nerve blocks decreases minimum alveolar concentration of isoflurane needed by the patient without affecting cardiovascular parameters or causing observable adverse effects.2 Nerve blocks provide analgesia in the postoperative period, improving patient comfort and decreasing the need for additional analgesics.2
• Use controlled forces and proper technique, including appropriately sized, sharp instruments and the use of a short finger stop. If the elevator slips during extraction, using a short finger stop prevents inadvertent penetration of the sublingual space, mandibular canal, nasal cavity, and orbit.

COMPLICATIONS

Fractured Tooth Roots

Use of excessive force or use of extraction forceps before the tooth is adequately elevated can lead to root fracture. Anatomic variations in root structure (e.g., hooked, curved, or bulbous roots) can predispose the root to fracture during extraction (FIGURE 3). In addition, the mesial root of the mandibular first molar in the dog has a groove along the distal aspect of the root in an apical coronal axis, which makes extraction of this tooth root more difficult.3

Sometimes, however, despite our best attempts, tooth roots fracture during oral surgery and additional surgery is needed to extract the root tip. The first step in root tip retrieval is to take a deep breath! Then follow these subsequent steps:

1. Take intraoperative radiographs. The radiographs will confirm the anatomy of the remaining root, the adjacent structures, and the pathology associated with the surrounding bone. Keep in mind the anatomy of the area, particularly the location of the neurovascular bundles, the mandibular canal (FIGURE 4), the nasal cavity, and the orbit.
   
   Figure 4. Dog cadaver (A) with bone overlying the neurovascular bundle (arrow) and tooth roots removed showing the proximity of the roots of teeth 308 and 309 to the mandibular canal

   Figure 4. Dog cadaver (B) with the neurovascular bundle removed showing the root tips of 309 (arrows) lingual to the neurovascular bundle and closely adjacent to the ventral cortex of the mandible.
2. Visualize the root tip. Creating an open exposure to retrieve a fractured root tip makes the procedure quicker and less traumatic for the patient.4 Your objective is to visualize the root tip before attempting to remove it. Visualization can be improved by removal of additional buccal bone, magnification, and adequate lighting. Never dig blindly for root tips.
3. Remove alveolar bone. To expose the remaining root structure and identify the periodontal ligament space, use a small bur to remove additional buccal alveolar bone. Perform this procedure with care because tooth roots can be located on the lingual or vestibular aspect of the mandibular canal.5 You can use a smaller round bur to create a groove in the mesial and distal periodontal ligament spaces to allow insertion of the dental elevator in these locations (FIGURE 5). If needed, a small bur can be introduced into the alveolus to create a circumferential “moat” around the root to allow introduction of a root tip elevator into this expanded periodontal ligament space.3 Do not remove excessive bone, and always consider the location of the neurovascular bundles, nasal cavity, mandibular canal, and orbit.
   Figure 5. Dog cadaver, showing fractured mesial root of tooth 206 with buccal bone removed.
4. Mobilize the root. After bone removal, place a small dental elevator into the periodontal ligament space of the root tip on the mesial and distal sides. Gently rotate the elevator to stretch the periodontal ligament. Do not use apical pressure because excessive apical pressure can displace the root tip into the mandibular canal, nasal cavity, or maxillary sinus. After the tooth root is mobile, it can be removed through the newly created buccal bone window. Root tip extraction forceps with fine tips may be used to assist in the removal of the mobile tooth root from the alveolus.

Do not blindly pulverize a fractured or resorbing root by using a bur on a high-speed handpiece. Potential complications of root pulverization include air embolism,6 subcutaneous emphysema, inadvertent penetration of the nasal cavity, damage to the neurovascular bundle in the mandibular or infraorbital canals, and displacement of the root apex into the nasal cavity or mandibular canal.

Very seldom is it appropriate to leave a root tip in place. Do so only if the risks of surgery to remove the root tip outweigh the benefits of removing the root tip. The surgical risks include: a patient who is not stable under anesthesia; the possibility that continued attempts at root tip removal may affect vital structures (nerves and blood vessels within the mandibular canal, the nasal cavity, or orbit); and the potential for significant destruction of surrounding bone or soft tissues or displacement of the root tip into the mandibular canal, nasal cavity, or retrobulbar space.4

Do not leave a root tip in place if you see any clinical or radiographic evidence of periodontal or endodontic disease associated with the tooth. Do not leave root tips in cats and dogs with stomatitis. For a fractured root tip to be left in place, the root tip must be small and deep within the alveolus.

If you decide that the benefit of fractured root removal does not outweigh the risks and the root tip will remain in place, take intraoral radiographs to document the remaining root structure. Referral to a veterinary dentist is recommended. Inform the client of the decision, the reason for the decision, and the possible clinical sequelae. Document the decision in the patient’s medical record. For follow-up, take radiographs of the retained root tip each year to look for any pathology associated with the remaining root fragment. If pathology is found, root tip retrieval is necessary.

In summary, fractured root tips are frustrating and sometimes difficult to remove. Intraoral radiographs must be obtained before extraction to evaluate the tooth structure and surrounding alveolar bone. Proper extraction technique minimizes the chances for fracturing root tips. Removal of buccal alveolar bone and proper sectioning of teeth facilitates extraction. Use of proper, sharp instruments and slow, controlled forces are recommended. Above all, be patient!

Displacement of Root Tips

While attempting to retrieve fractured root tips, you might displace a tooth root into the mandibular canal, nasal cavity, or maxillary sinus.7 Root displacement can be avoided by removing alveolar bone to enable visualization of the root tip and carefully elevating fractured root tips with minimal apical force. If displacement occurs, it is desirable to remove the root tip or tooth fragment. Removal is usually facilitated by removal of additional bone and careful evaluation to identify the displaced root tip. When removing root tips from the mandibular canal, avoid the man