Periodontal Disease

Typical Signalment

Pure bred cats are particularly susceptible and include:
- Persian
- Maine Coon
- Burmese
- Siamese
Affects majority of cats over two years of age.
Certain breeds of dogs are thought to be susceptible to an aggressive form of the disease including:
- Greyhounds
- Maltese dogs
Small breed dogs are more prone to tooth crowding, predisposing the animal to the initiation and rapid progression of the disease

Description

Periodontal disease is essentially an inflammatory response by the supporting structures of the teeth known as the periodontium. These structures include:

gingiva
periodontal ligaments
cementum
alveolar bone

It is the most common dental disease in dogs and cats and the major cause of tooth loss in both species. There are numerous factors that contribute to the formation of the disease but the primary agent is dental plaque. Plaque accumulates at the gingival margin, partly due to insufficient oral hygiene.

Initially the bacterial flora tend to be non-motile aerobes or facultative anaerobes. However, as the supply of oxygen is reduced by supragingival plaque accumulation and pocket formation, the bacterial flora become more motile and anaerobic. Important bacterial flora responsible include:

Porphyromonas gingivalis
Bacterioides asaccharolyticus
Fusobacterium nucleatum
Actinomyces viscosus
Actinomyces odontolyticus

Gingivitis and periodontitis are the two main forms of the disease. Gingivitis is the early form of the disease and often but not always progresses to periodontitis.

Gingivitis - Reversible inflammation of the marginal gingival tissues that does not affect the periodontal ligament or the alveolar bone.

Periodontitis - Inflammation and irreversible destruction of the tooth's supporting structures that includes the gingiva, periodontal ligament, alveolar bone and root cementum. It usually occurs after years of plaque acculmulation and gingivitis. The epithelial attachments of the tooth regress apically and there is absorption of the associated alveolar bone, resulting in permanent loss of tooth support.

Diagnosis

Clinical Signs

Depend on the severity of gingival hyperplasia and the degree to which the teeth are covered but include:

pain on mastication
haemorrhage (mild to moderate)
reluctance to eat
drooling
dysphagia

Diagnostic Imaging

Oral radiographs should be taken to rule out concurrent conditions. One such condition is periodontitis which is demonstrated radiographically by alveolar bone loss associated with pocket formation between the tooth crown and gingiva.

Biopsy

Biopsy samples should include those areas of gingiva that show signs of inflammation with a softer than normal texture. Any gingiva with radiographic signs of bone involvement should also be sampled.

Treatment

The suspected cause of the condition should be corrected first. This may include a multimodal treatment plan aimed at controlling plaque formation including teeth brushing and providing the animal with sticks/toys that clean the teeth crowns

Gingivectomy and gingivoplasty - should be carried out under general anaesthetic if significant pseudo-pockets are present between the gingiva and teeth crowns. The aim should be to eliminate the pseudopockets and re-establish the normal anatomy of the gingival margin.
- Electrosurgery and Laser surgery - care must be taken with electrosurgery to avoid contact between the teeth crowns and the electrodes to prevent irreversible heat damage to the pulp.

Prognosis

The prognosis following surgical excision and histopathology is good. However, local recurrence is possible but less common if a treatment plan aimed at reducing plaque formation is implemented. A re-examination of the patient should be carried out at least every 6 months to assess for signs of recurrence and the sufficiency of plaque control measures.

References

Tutt, C., Deeprose, J. and Crossley, D. (2007) BSAVA Manual of Canine and Feline Dentistry (3rd Edition) BSAVA

Merck & Co (2008) The Merck Veterinary Manual