E is for elegant extraction
A crown amputation is described and reasons for the procedure are discussed
When to Extract
Extractions are indicated when stage IV periodontal disease is present (the tooth has more than 50% support loss based on probing depths, greater than stage III mobility, stage III furcation exposure, or when the gingival recession has progressed past the mucogingival line). Extraction is also the best therapy for stage III periodontal disease, where the tooth has 25% to 50% support loss, and the owner or patient will not allow appropriate home care.
Some fractured teeth are best extracted, especially those with pulp exposure plus stage III or IV periodontal disease, marked internal resorption, or when root canal therapy is impossible because of the owner’s wishes or the practice’s capability and lack of referral option.
Extractions are also indicated to treat tooth resorptions exposed to the oral cavity. Additionally, cats affected by feline chronic stomatitis can be helped through extraction of selective teeth or all the teeth.
Supernumerary teeth that cause crowding, predisposing the teeth to periodontal disease, should be extracted. Additionally, persistent deciduous teeth should be removed as soon as possible at the time of diagnosis to prevent the potentially harmful malposition of the adult teeth.
Complications of routine extractions
Consider why complications occasionally occur during extractions:
- Excessive pressure on the crown/ root interface leads to a root fracture.
- Excessive bleeding secondary to inadvertently excising neurovascular bundles occurs during the removal of buccal alveolus, creating improved exposure.
- Mandibular jaw separations are caused by excessive pressure on bone weakened by apical periodontitis.
Fortunately, these complications can be mitigated by first performing crown amputations.
Operative technique
- Administer local anesthesia.
- Insert the scalpel blade into the gingival sulcus and advance it apically 360 degrees to incise the coronal periodontal ligament.
- Create a buccal full-thickness mucoperiosteal envelope or pedicle flap, including the surface mucosa, submucosa, and periosteum.
- Use a #701 surgical tapered crosscut fissure bur to create a gutter of bone apical to the cementoenamel junction.
- Position the bur horizontally at the cementoenamel junction to remove the crown.
A #701 Surgical bur used to groove the right mandibular first molar crown.
6. Lift the crown gently off the roots using extraction forceps.
Rongeurs used to raise the right maxillary fourth premolar crown from the underlying roots in a cadaver specimen.
7. Use the #701 surgical tapered crosscut fissure bur to create a moat around the root(s) to facilitate the insertion of the sharpened wing-tipped elevator blade.
Figure A: The maxillary fourth premolar in a cadaver specimen exposing the roots after crown removal.
Figure B: The appearance of the mandibular first molar roots after crown amputation.
Figure C: A #701 Surgical bur used to create moats around the canine roots in a cadaver specimen.
Figure D: A #701 Surgical bur used to create a trench around the maxillary fourth premolar in a cadaver specimen.
8. Remove sufficient buccal alveolar bone to expose the root surface.
Figure A: A #701S bur used to remove buccal alveolar bone overlying the mandibular first molar roots.
Figure B: Creating a moat for easy wing tip insertion for a maxillary canine tooth in a cadaver specimen.
9. Apply moderate torsion with an appropriate-sized wing-tipped elevator circumferentially until marked root mobility is created.
A wing tipped elevator placed into the moat to facilitate canine root extraction in a cadaver specimen.
10. Remove the roots with a root toothtip pick or fine extraction forceps.
Delivery of the maxillary canine root is shown.
11. Clear the sharp alveolar crest with the football diamond bur before suturing.
12. Enlarge the flap if needed to facilitate tension-free closure.
Key takeaway
Removing the crown as part of the extraction process is a win for all. It decreases the flap size needed to access the buccal alveolus, allows excellent visualization of the roots, decreases hemorrhage from inadvertently incising arterial supply, and decreases root fracture during extraction and stress.
Elegance is a good thing.
Jan Bellows, DVM, DAVDC, DABVP, FAVD, received his undergraduate training at the University of Florida and his doctorate in veterinary medicine from Auburn University. After completing an internship at the Animal Medical Center in New York, New York, he returned to Florida, where he practices companion animal medicine surgery and dentistry at All Pets Dental in Weston. He has been certified by the American Board of Veterinary Practitioners (canine and feline) since 1986 and the American Veterinary Dental College (AVDC) since 1990. He was president of the AVDC from 2012 to 2014 and is president of the Foundation for Veterinary Dentistry.
