Off with the crown?

Editors Note: In a new series, DVM Newsmagazine asks experts within a variety of veterinary specialties to bust commonly held medical, business or professional myths. This month, we bite into dentistry.

Myth: Crown amputation is the new treatment of choice for feline odontoclastic resorptive lesions (FORL or RL) in cats.

REALITY: Crown amputation with intentional root retention for feline teeth with RL is an acceptable alternative to complete extraction of the entire tooth in select cases that meet specific criteria.

There appear to be two distinct types of RL. Type I lesions are inflammatory in nature and arise at the neck region of the tooth. (Figure 1) The periodontal ligament surrounding the teeth of these Type I lesions is generally intact and the gingiva is inflamed and likely painful.

These teeth are not candidates for crown amputation and intentional root retention. The entire tooth and root must be removed.

Type II lesions are non-inflammatory and tend to start below the neck region of the tooth (Photo 2). Resorption starts at the level of the cementum and the periodontal ligament space becomes obscured radiographically as the condition progresses. If complete radiographic and gross visual evidence of the periodontal ligament is lacking, and no periodontal or endodontic pathology are evident, only then can crown amputation and intentional root retention be considered. It should be mentioned that some veterinary dentists still support complete removal of the root in all teeth regardless of RL type.

Figure 1: Type 1 resorptive lesion. Significant destruction of the distal aspect of the crown of the mandibular left first molar (tooth 409). The periodontal ligament is intact. This tooth is not a candidate for crown amputation. And Figure 2: Type II resorptive lesion. There is no discernible periodontal ligament present surrounding the mandibular left canine tooth (tooth 404). This tooth could be considered for crown amputation, but gross vital evaluation should be done before a decision is made.

Treatment via crown amputation involves removing all of the tooth structure to bone level with a round carbide or diamond bur and suturing the gingiva over the defect with a 5-0 monofilament absorbable suture material.

Brett Beckman

Brett Beckman, DVM, FAVD, Dipl. AVDC practices referral dentistry at Affiliated Veterinary Specialists, Orlando, Fla.; Noah's Animal Hospitals in Indianapolis; and at Florida Veterinary Dentistry and Oral Surgery in Punta Gorda, Fla. He is president-elect of the American Veterinary Dental Society and board eligible in the American Academy of Pain Management.