TECHNIQUE

Canine Tooth Removal in Bears  (Disease Investigation & Management - Treatment and Care)

Procedure 1: Click here for full-page view with caption Click here for full-page view with caption Click here for full-page view with caption Click here for full-page view with caption Procedure 2: Click here for full-page view with caption Click here for full-page view with caption Click here for full-page view with caption Click here for full-page view with caption Click here for full-page view with caption Click here for full-page view with caption

Summary Information
Type of technique Health & Management / Disease Investigation & Management / Techniques:
Synonyms and Keywords --
Description

NOTE: Although the procedures are described below as accurately as possible, these descriptions are NOT a substitute for learning the procedures by watching and assisting a veterinarian who is already experienced in the technique.

Anaesthesia and perioperative analgesia
  • Induce anaesthesia in the bear. Various options are possible see Treatment and Care - Bear Anaesthesia
  • One the bear is fully immobilised, intubate and maintain with isoflurane on a circle system.
  • Give appropriate perioperative analgesia, e.g. carprofen 4 mg/kg intravenously and butorphanol 0.07 mg/kg intramuscularly immediately post-induction. (P3.2006a.w1)
  • Provide local analgesia: bupivacaine provides 3-10, usually 6-8, hours of analgesia; lidocaine (lignocaine) could be used to provide a shorter period of local anaesthesia: (P3.2006a.w1)
    • For maxillary canine extraction, use an infraorbital nerve block. (P3.2006a.w1)
    • For mandibular canine extraction, a maxillary nerve block can be combined with a mental nerve block (to improve analgesia if the maxillary nerve block fails). (P3.2006a.w1)
  • Monitor during anaesthesia (e.g. visual monitoring, pulse oximetry, capnography). (P3.2006a.w1)
  • Give intravenous fluids during surgery. (P3.2006a.w1)

(P3.2006a.w1)

Open Extraction Procedure 1 (standard approach to removal of canine teeth in carnivores)
  • Raise a gingivo-muco-periosteal flap from the distal edge of the second premolar to a point just rostral to the canine tooth, making sure it is rostral to the tooth root:
    • Insert a scalpel blade into the gingival sulcus (the crevice surrounding the tooth, between the tooth and the free gingival margin) and cut down to the crestal bone (the edge of the bone surrounding the tooth).
    • Use a periosteal elevator to free the attached gingiva from the underlying bone.
    • Make a releasing incision at one or both ends.
      • Slanting the incision away from the tooth being extracted increased the length of the base of the flap, ensuring a good blood supply and good healing. (B452.10.w10)
      • Producing a long flap (rostro-caudally, from well in front of to well behind the tooth) increases visibility and facilitates access for instruments. (B452.10.w10)
    • Work the periosteal elevator beyond the mucogingival line, lifting the periosteum off the bone and thereby freeing the overlying alveolar mucosa to expose the tooth and the alveolar bone.
      • Make sure the mucoperiosteum (mucous membrane and periosteum) has been fully sectioned (cut through) before attempting elevation of the flap, to avoid separation between the gingiva/alveolar mucosa and the periosteum; such separation makes it difficult to raise the flap and causes unnecessary trauma to the soft tissues. (B452.10.w10)
    • Raise and reflect the flap.
      • This increases visibility and access to the surgical site and reduces the risk of trauma to the flap tissues during bone removal. (B452.10.w10)
    • N.B. Make sure, in the mandible, not to transect the neurovascular bundle which exits the mental foramen.
    • Remove the buccal bone plate to just beyond half way to the root apex.
      • Remove bone over the maximal bulbosity of the root. (B452.10.w10)
      • Use round tungsten or steel burrs on straight handpieces, either electric or air motor driven, to remove the vertical bone. These handpieces provide the required torque and power combined with tactile and speed control. (B452.10.w10)
    • Advance the drill apically, medially and distally to create a small gutter between the root and the bone, to outline the root. Take care to ensure the gutter is between the tooth root and the bone.
    • Apply elevators mesially and distally in the gutter, and rotate the elevator to loosen the tooth on its long axis.
      • For mandibular (lower) canines, the elevator can be applied on the lingual aspect of the tooth. For the maxillary (upper) canines it is preferable not to use the elevator on the palatal side, to avoid the risk of tipping the root apex medially and perforating the nasal bone plate.
    • If the tooth does not loosen, drill more of the buccal bone plate away rather than using excess force on the elevator.
    • Once the tooth is very loose, lift it out of the socket using elevators, forceps or fingers.
    • Carefully check the surgical site and remove loose edges of bone or granulation tissue. (B452.10.w10)
    • Smooth the edges of the alveolar bone, removing any sharp bone spicules.
    • Flush the alveolus.
      • Irrigate with water only, not water/air or air alone. (B452.10.w10)
    • Freshen the flap edges and if necessary round off the buccal and/or palatal margin of the alveolus to ensure a tension-free closure. (B452.10.w10)
    • Replace the flap and suture it in place to close the socket.
      • Suture in a tension-free manner, using absorbable sutures. (B452.10.w10)

    (B452.10.w10, B470.14.w14)

Open Extraction Procedure 2 (alternative, non-standard)
  • Make an incision from the gum down over the root of the canine along the whole length of the root.
  • Elevate the gingiva (gum) with a periosteal elevator to expose the bone; reflect the gum to either side.
  • Using an osteotome (1 cm wide), remove the lateral alveolar wall over the root of the canine tooth.
  • Using the osteotome and dental elevators, gently elevate the rostral, medial and caudal aspects of the root from their attachments (i.e. break down the attachments of the tooth root to its socket). Note: only the proximal 2/3 of the root appears to be attached to the socket by the peridontal ligament.
  • Elevate and remove the tooth from the socket.
  • Scrape the inner alveolar surface to remove any debris from the socket.
  • Use bone rongeurs to remove any splinters of bone from the alveolar crest (the edge of bone around the tooth socket).
  • Lower the alveolar crest using bone rongeurs.
    • This will allow the edges of the gum to be placed together and sutured over the empty socket without tension.
  • Flush the extraction site with dilute chlorhexidine gluconate.
  • Insert a calcium/sodium alginate dressing (Kaltostat, Conva Tec Ltd.) into the alveolar socket to fill the defect, provide a matrix for clot formation and provide a support for the gingiva.
    • The dressing also provides a barrier to help prevent food impaction in the socket if any dehiscence of the gingiva occurs. 
  • Replace the gingiva and debride the margins to aid healing by primary intention.
  • Suture the gingival margins with tension-relieving sutures: polydioxanone (PDS, Ethicon) in a cruciate pattern is suggested.

(P3.2006a.w1)

Post-operative care

  • Post-operative analgesia orally for 3-5 days as required (depending on clinical evaluation). 
  • Antibiotics orally (these can be given in a treat such as a flavoured milkshake).
  • Monitor wound healing daily, when the oral medications are given

(P3.2006a.w1)

Appropriate Use (?)
  • When canines have been damaged resulting in pulp exposure, and neither pulpotomy [Pulpotomy in Bears] nor root filling [Root Canal Procedures in Bears] is appropriate: e.g. vertical fractures extending under the gum or affecting the root; infected teeth with an open root apex, or with associated peridontal disease; or if materials and equipment for pulpotomy or root canal treatment are not available. (B214.3.4.w16, J60.12.w1, V.w6)
  • It has also been suggested for situations in which canines have been damaged resulting in pulp exposure, and filling the tooth is not appropriate because regular check-ups/follow up will not be possible. (P3.2006a.w1) However, it should be noted that bears maintain root-fillings well if the fillings are properly applied. (B407.w18)
Notes
  • The technique described as "Procedure 2" above, involving a gingival incision directly over the tooth root, is "contrary to all principles of oral surgery" (B452.10.w10), with the suture line overlying the bony defect, but more than 150 canine tooth extractions have been carried out on rescued Ursus thibetanus - Asiatic black bears using this method, without any complications. (P3.2006a.w1)
  • Continuous irrigation with water is important while bone is being removed: to cool the alveolar bone, preventing overheating and necrosis; to cool the burr, which will have its efficiency lost if it overheats; to wash away bone chips, so they do not clog the burr; and to keep good visibility of the surgical site. (B452.10.w10)
  • Surgical aspiration (suction) is required to take away irrigation water and blood and maintain good visibility. (B452.10.w10)
Complications/ Limitations / Risk
  • Risk of breakdown of the gingival sutures and food packing into the alveolus.
  • With bupivacaine as a local anaesthetic there is a risk that the bear might self-traumatise after waking from the general anaesthesia. However, this has not been a problem in the series of more than 150 operations carried out on Ursus thibetanus - Asiatic black bear. (P3.2006a.w1)
  • According to the principles of dental surgery, healing of the gingival incision over an osseous defect [as created in the first procedure described] is unpredictable; there is increased risk of dehiscence of the flap. (B452.10.w10)
  • Possible sequelae to removal of large canine teeth in carnivores include "post-operative infection, malocclusion, bone resorption, jaw fracture and damage to adjacent teeth." (B470.19.w19)
Equipment / Chemicals required and Suppliers
  • General anaesthetic agents and appropriate equipment for anaesthetic administration and monitoring

  • Local anaesthetic agent

  • Analgesics

  • Antibiotics

  • Anaesthetic monitoring equipment

  • Needles and syringes for injection

  • Dental instruments

  • Suture materials and instruments

Expertise level / Ease of Use
  • This procedure should be carried out by personnel with experience and training in dental surgery in animals.
Cost/ Availability
  • The costs of this procedure include the costs of the personnel required (minimum one suitably qualified person to carry out the dental work and one to monitor the anaesthetic), and costs of appropriate equipment.
Legal and Ethical Considerations
  • In some countries there may be legislation restricting the use of this type of technique to licensed veterinarians. For example in the UK: "The Veterinary Surgeons Act 1966 (Section 19) provides, subject to a number of exceptions, that only registered members of the Royal College of Veterinary Surgeons may practice veterinary surgery." (see: LCofC1 - RCVS Guide to Professional Conduct 2000 - Treatment of Animals by Non-Veterinary Surgeons).).
Author Debra Bourne MA VetMB PhD MRCVS (V.w5)
Referee Suzanne I Boardman BVMS MRCVS (V.w6)
References B214.3.4.w16, B452.10.w10, B470.14.w14, B470.19.w19, J60.12.w1, P3.2006a.w1, V.w6

Return to Top of Page