Feline dentistry
TORONTO, ON – Practicing preventive feline dentistry is an essential part of quality dental care in veterinary hospitals. While there are many oral and dental diseases common in both cats and dogs, there are dental diseases specific to cats that aren’t well understood. As a result, they often go either unnoticed or when they are recognized, are left untreated, explained Gary S. Goldstein, DVM, FAVD, DAVDC, speaking at the Ontario Association of Veterinary Technicians Conference. When they are identified, veterinary staff and their clients should be educated on proper prevention and treatment.
Common feline oral and dental diseases specific to cats are juvenile gingivitis, caudal stomatitis, and tooth resorption.
Juvenile gingivitis
It is generally accepted that accumulation of calculus supra-gingivally, along the gum line, and extension subgingivally play a role in the progression of gingivitis. In cats it is not uncommon to see the development of gingivitis at 6 to 12 months of age, often associated with little or no calculus accumulation. The severity is not always related to the amount of calculus present. The exact cause is unknown, however some theories include viral, breed disposition, genetic and environmental influences, diet, immune suppression, and of course plaque and calculus build up.
Clinically, the gingivitis may be mild localized inflammation of the gingival tissues as seen by a bright red line, to more severe inflammation where the gingival tissues are extremely red and will bleed easily on probing, to severe inflammation and hyperemia resulting in oral pain and bleeding gums. Pseudo pockets will form as a result of severe gingival tissue hyperplasia.
Treatment includes elimination of plaque and calculus formation by performing a thorough dental prophylaxis including supra- and sub-gingival scaling, and polishing and oral rinsing with chlorohexidine solution. In severe cases of gingival hyperplasia and inflammation it may be necessary to perform gingivectomies to eliminate the psuedo pockets that have formed. Dr. Goldstein stressed that the final step is to reduce plaque build up by effectively educating the client on the importance of regular dental home care.
Gingival buccal/caudal stomatitis
Gingivial buccal/caudal stomatitis is a chronic condition that involves the entire oral cavity, including the gingival tissues and oral mucosa. Clinically it is recognized with severe hyperemia, inflammation, and bleeding that can be associated with varying degrees of ulcerations in the oral cavity, lips and even the tongue. There is proliferation of friable granulation tissue well into the palatoglossal folds and the entire oral pharyngeal region.
Presenting signs include severe oral pain, halitosis, ptyalism, inappetance, weight loss, difficulty in eating and swallowing, change in behaviour, dropping food out of the mouth when attempting to eat, and general lethargy. Severe periodontal disease with bone loss, gingival recession, purulent discharge, the presence of feline odontoclastic resorptive lesions, and retained root fragments may be present.
The exact cause is unknown, but theories include viral, immune deficiency or immune hyper responsiveness to a chronic foreign antigen, root resorption and retained roots, tooth resorptions, certain drugs, stress, and environmental influences.
The most important aspect of a complete treatment planning session is to first educate the client so they understand that long-term prognosis is guarded and to expect multiple veterinary visits for ongoing care. When the disease has progressed to a state of severe hyperemia, generalized stomatitis, severe inflammation and extensive overgrowth of granulation tissue in the oral pharyngeal region, total mouth extraction is warranted. Full mouth dental radiographs should be taken to identify tooth abnormalities such as tooth resorption, retained root fragments, and severe bone loss. All teeth, including any broken and retained roots, are extracted. The canine teeth may be salvaged during the initial extraction treatment session; however, they may need to be extracted in the future if the condition fails to improve. Dr. Goldstein noted that some veterinary dentists recommend extracting all the teeth including the canine teeth at the initial extraction session. Steroid injections may be used in select cases post extraction, but may retard healing, mask the potential success of the extractions and should be avoided if at all possible. They may be warranted when caudal inflammation is severe enough to compromise airflow and food intake. Oral antibiotics and pain medications should be used post extraction in all surgeries.
The most important point is to understand that long-term prognosis is poor, and keeping the disease under control and the cat as pain free as possible and comfortable are the primary goals.
Tooth resorption
The prevalence of these lesions varies between 20-75% of the feline population and most likely represents the most common feline disease of the tooth structure. The most common locations are the lower third premolars and molars and the upper fourth premolars, however, they can be seen on all the teeth including the incisors. Currently there is no known treatment or diet that prevents the development and progression of tooth resorption.
Pathology
External resorption can be classified into three basic types: surface, inflammatory, and replacement. Surface root resorption occurs in all feline teeth, however, the two types we are most concerned with are inflammatory, which is associated with periodontal inflammation, and replacement resorption, which currently has an unknown etiology.
Clinically and radiographically there is an early degeneration of the periodontal ligament, a gradual narrowing of the periodontal space, and subsequent dentoalveolar ankylosis where the tooth and alveolar bone fuse together. The process begins in the cementum where the hard tissues are destroyed causing calcification of the organic layers within the periodontal ligament that could result in this ankylotic fusion. This ankylosis is incorporated into the process of normal bone remodelling, which under hormonal control, will be gradually resorbed and replaced by bone (replacement resorption). Osteoclasts begin destroying the root surface within the cementum-bone like tissue that has fused together. The process begins in the cementum, progresses into the dentin, and spreads to the dentin of the crown as well as the root. The enamel is eventually resorbed and/or fractures as a result of the underlying tooth damage.
Dr. Goldstein added that the exact etiology of tooth resorption is still not certain and more research is needed to determine the cause, treatment, and prevention.
Diagnosis
The lesions can be detected by visual inspection, tactile examination with a dental explorer, and radiology. Often times there is no visible or clinical tooth resorption, however, dental radiographs localized to the root will be seen. Full mouth radiographs are recommended for all cats presented for dental procedures such as dental prophylaxis, extractions, or resorptive lesions.
Stages of tooth resorption
Stage 1: Lesions extend into cementum only.
Stage 2: Lesions may extend into the crown and/or root dentin, but not the pulp cavity.
Stage 3: Lesions may extend into the crown and/or root dentin, and involve the pulp cavity.
Stage 4: Lesions have produced extensive structural damage to the tooth (including the root and the crown). At this stage there may be both crown and root involvement, or crown damage with no root damage or root damage with no crown affected.
Stage 5: Crown is lost, root remnants remain.
Treatment
The current treatment of choice is surgical extraction of the affected teeth and roots by creating a gingival flap, removing buccal bone, sectioning the affected teeth, extracting the tooth roots, performing alveoloplasty to smooth the alveolar ridges, and then suturing the extraction site closed with absorbable sutures. In type 2 root types where the root is beginning to be replaced by bone and there is loss of identifiable tooth root structure, subgingival amputation below the gum line is a treatment option. CVT
