Contributors: Jan Bellows, David Crossley, Mark Thompson
Species: Feline | Classification: Techniques
Introduction Requirements Preparation Procedure Aftercare Outcomes Further Reading
- Mobile teeth.
- Periodontal disease Periodontal disease.
- Supernumerary teeth: if affecting occlusion or crowding other teeth.
- Persistent deciduous teeth Retained temporary teeth (Persistent primary teeth).
- Advanced caries.
- Fractured teeth Dental fracture: if beyond repair, eg long axis root fractures, root fractures in the middle third, teeth with crown fractures when no endodontic treatment is authorized.
- Teeth on fracture line of fractured mandible or maxilla.
Skull smaller and more fragile in cat than in dog.
- Endodontic techniques.
- Restorative techniques.
Criteria for choosing test
- Ensure client understands that general anesthesia is necessary.
- Scalpel blade No. 11 and handle.
- Molt p9 periosteal elevator .
- Root tip pick.
- Svenska luxators : 3 mm straight, 3 mm curved.
- Lindo-Levien elevators: LLL, LLM, LLS.
- Needle holder .
- Fine-toothed dissecting forceps.
- Straight scissors 5 inch .
Must be sharp.
- Dental elevator: a selection of sizes to match tooth root size and diameter.
- Cutting burrs : 701, 702, 330, round 2, 3, 4 and 5
- Bone file .
- Drapes, clips, swabs.
- Suture material: monocryl 1.5 metric rapidly absorbable suture with swaged on cutting needle.
- Opioid .
- Mouth prop.
Avoid using sprung mouth gags in cats as can cause serious muscle damage.
Step 1 - Single-rooted teeth
- Cut epithelial attachment at bottom of sulcus with No. 11 blade at 25° to long axis of root.
- Select an elevator or luxator with correct blade.
Select blade with circumference one third the size of a target root.
- Introduce the elevator/luxator in an apical direction between alveolar bone and root surface .
- Rotate luxator blade circumferentially while maintaining apical pressure .
- Stop from time-to-time to allow the hydraulic pressure of hemorrhage from periodontal ligament to assist expulsion of root from alveolus.
- Continue working luxator against all surfaces of root until loose .
- Extract loose root .
- Debride alveolus, removing bone spikes .
- Radiograph to ensure complete removal.
- Suture gingiva.
Step 2 - Multi-rooted teeth
- Create one or more single roots for extraction.
- Break down epithelial attachment (see single-rooted tooth - earlier).
- Lift full-thickness mucous membrane and gingiva from bone using Molt elevator .
- If necessary incise gingiva at caudal and mesial margins diverging away from root axis.
- Remove semi-circle of crestal bone, using 701 cross-cut taper fissure burr, to identify furcation angle.
- Split tooth in two halves cutting from furcation coronally.
- Apply elevator into cut channel and gently rotate to push two roots apart.
- Hold pressure for 10 seconds then turn blade around and repeat procedure.
- Combine with longitudinal elevation of tooth root.
- Keep applying pressure until one or both roots becomes loose.
- Remove loose root.
- Elevate remaining root normally.
- Debride, filing off bone spikes.
- Suture gingiva.
- Radiograph to ensure complete removal.
Step 3 - Upper canine
- Sever epithelial attachment (see single-rooted teeth).
- Locate end of root by digital palpation following lateral canine eminence.
Locate 2 mm rostral to rostral margin of root to avoid post-extraction suturing over a void.
- Extend incision forward to caudal margin of corner incisor and caudal to mesial root of lower premolar 2.
- Use Molt elevator to lift full thickness mucoperiosteal flap from leading margin at mesial angle of canine backwards to expose lateral canine eminence.
- Use a 701 cross-cut fissure burr or similar high speed, water cooled handpiece.
- Insert a luxator blade into the mesial channel down the long axis direction and rotate in a lateral direction.
- Repeat until periodontal ligament begins to loosen.
- Apply the blade to caudal channel in a similar direction and rotate.
- Repeat from side-to-side until root loosens and can be gently lifted from the socket with forceps.
- Gently irrigate the socket with saline 0.05% chlorhexidine gluconate.
Blood or fluid from ipsilateral nostril indicates a fistula (see complications).
- Suture flap, using interrupted sutures. Start at leading edge of flap nearest caudal margin of upper incisor.
ESSENTIAL that sutures are not under tension otherwise dehiscence will occur.
Step 4 - Lower canine
- More difficult than extracting upper canine tooth: long axis of tooth is buccolingual rather than dorsoventral; apex lies at caudal end of mandibular symphysis .
- Sever epithelial attachments as for single-rooted teeth .
- Incise oral mucous membranes on lingual aspect along the long axis of tooth from mesial margin .
- Cut channel round outline of root on lingual aspect to mid root depth or remove lingual bone plate with bone chisel.
- Apply luxator blade to caudal channel along long axis of root - rotate blade while applying pressure apically to rotate root out of alveolus.
- Repeat process in reverse with blade in mesial channel.
- Irrigate and suture (see upper canine extraction).
Step 5 - Deciduous teeth
- Indications: crowding. Most common is lingually displaced mandibular canines with the tips of the lower canines occluding into the hard palate.
- All deciduous teeth are rostral to their permanent counterparts with exception of lower canines which are buccal to permanents.
- Extraction follows same principle as permanent teeth, but deciduous teeth more fragile and prone to fracture.
Excessive luxation may damage permanent tooth if it is undergoing amelogenesis at this time - important to know location of permanent tooth bud.
- Pre- and post-extraction radiography is very useful.
- Opioid administered pre-operatively or intra-operatively.
- Antibiotics: good bone penetration; gram-negative anaerobic spectrum Clindamycin.
Oro-nasal fistula (ONF)
- At any location most commonly upper canines and caudally to them, where bone plates thinnest, ie medial to upper canine and upper premolar 4.
- Requires complex flap surgery. Correct attention at the time of extraction can limit the need for complex flap surgery later. Debride socket gently with 0.05% chlorhexidine gluconate and suture the tissues closed without tension. Treat with suitable antibiotics. Review after 4-6 weeks to identify the need for flap surgery.
- Most commonly caused by tension on sutures or active infection at site.
Expect 20% contraction of soft tissues during healing.
- Many oro-nasal fistulae stay open due to pressure differential between nasal and oral cavity.
- After 6 weeks, if ONF present, closure is indicated Oronasal fistula repair otherwise chronic rhinitis will occur (although may not be clinically apparent).
- Most sockets stop bleeding quickly post-extraction with little need for attention beyond gentle pressure.
- Packing socket with polylactic acid granules (expensive) or bone graft (cheap) may help.
- Hemostatic gauze may help but has to be removed after a short period.
Beware of clotting factor defects. Pre-test clotting factors to assess suitability for surgery or bleeding time .
- Hospitalize overnight if necessary.
- Common with poor technique. Carnivore teeth taper towards the apex. Over-robust and impatient elevation will fracture the root.
- A fractured fragment containing necrotic pulp or in an infected periodontal pocket will cause bone lysis and must be removed:
Either Use a root tip pick or fine blade luxator to loosen and remove root tip.
Or Burr away part of the bone plate to remove the root tip.
Mandibular body fracture
- Beware of extensive bone loss predisposing to fracture.
Pre-operative radiography may be helpful in assessing risk.
- Support body of mandible with the palm of the hand during tooth elevation.
Mistaken removal of permanent tooth
- Use radiography to differentiate temporary from permanent tooth - temporary teeth may have a less distinct root morphology.
Do not extract tooth unless sure it is temporary - seek expert advice if necessary.
- See under Aftercare/Complications.
Reasons for Treatment Failure
- See earlier.
- Recent references from PubMed and VetMedResource.
- Wiggs R B, Lobprise H, Mitchell P Q (1998) Oral and periodontal tissue. Maintenance, augmentation, rejuvenation and regeneration. Vet Clin North Am Small Anim Pract 28 (5), 1165-1188 PubMed.
- Smith M M (1996) Lingual approach for surgical extraction of the mandibular canine tooth in dogs and cats. JAAHA 32 (4), 359-364 PubMed.
- DuPont G (1995) Crown amputation with intentional root retention for advanced feline resorptive lesions - a clinical study. J Vet Dent 12 (1), 9-13 PubMed.
- Scheels J L, Howard P E (1993) Principles of dental extraction. Semin Vet Med Surg Small Anim 8 (3), 146-154 PubMed.
Other sources of information
- Wiggs R B, Lobprise H B & Lipincott-Raven (1997) Veterinary Dentistry, Principles and Practice.