6 Natural progression of disease
The dog was seen in primary practice for a non-oral problem (suturing of a skin laceration after running through a barbed wire fence while chasing rabbits). The owners were concerned about a possible oral infection as the dog had halitosis. They were worried about the risk of infecting their children as the dog was licking them in the face.
(a) All clinical findings are reported on the front page of the dental record. Normal periodontal probing depth (PPD) is not noted on the dental record to avoid clutter. This dog had no increased periodontal probing sites. Apart from the generalized gingivitis, the only other abnormality detected was absence of 105, 305 and 405.
(b) Details of treatment are reported on the back page of the dental record. Treatment consisted of periodontal therapy (supra- and subgingival scaling and crown polishing). Radiographs were taken that confirmed that 105, 305 and 405 were congenitally absent.
After Gorrel C, Derbyshire S (2005): Veterinary Dentistry for the Nurse and Technician, with permission of Elsevier. After Gorrel C, Derbyshire S (2005): Veterinary Dentistry for the Nurse and Technician, with permission of Elsevier.
In summary, examination under general anaesthesia confirmed the moderate generalized gingivitis (Fig. 6.2a, b). There was no evidence of periodontitis, i.e. no gingival recession and no increased periodontal probing depth at any site (Fig. 6.3). There was moderate accumulation of calculus, especially on the buccal aspect of the upper fourth premolar and first molar bilaterally (Fig. 6.2a).
(a) Note the swelling and reddening of the gingival margin indicating moderate to severe gingival inflammation in response to the accumulation of plaque. The buccal tooth surfaces are covered in dental deposits (plaque and calculus).
Figure 6.3 Lateral photograph of gingival probing of sulcus of 107. The probe is inserted at several sites around the whole circumference of each tooth to measure periodontal probing depth. In this dog, the probe could not be inserted to a depth greater than 1–2 mm at any site around any tooth, i.e. only normal sulcus depths were recorded. This is a case of gingivitis, with no evidence of periodontitis.
In gingivitis, the plaque-induced inflammation is limited to the soft tissue of the gingiva. Sulcus depths are normal (i.e. periodontal probing depths are 1–3 mm in the dog and 0.5–1 mm in the cat). As periodontitis occurs, the inflammatory destruction of the coronal part of the periodontal ligament allows apical migration of the epithelial attachment and the formation of a pathological periodontal pocket (i.e. periodontal probing depths increase). If the inflammatory disease is permitted to progress, the crestal portion of the alveolar process begins to resorb. Alveolar bone destruction type and extent are diagnosed radiographically. The resorption may proceed apically on a horizontal level. Horizontal bone destruction is often accompanied by gingival recession, so periodontal pockets may not form. If there is no gingival recession, the periodontal pocket is supraalveolar, i.e. above the level of the alveolar margin. The pattern of bone destruction may also proceed in a vertical direction along the root to form angular bony defects. The periodontal pocket is now intra- or subalveolar, i.e. below the level of the crestal bone.
Diagnosis of periodontal disease relies on clinical examination of the periodontium in the anaesthetized animal. In addition, radiography is mandatory if there is evidence of periodontitis on clinical examination. It is essential to differentiate between gingivitis and periodontitis in order to institute appropriate treatment. In individuals with gingivitis, the aim is to restore the tissues to clinical health; in individuals with established periodontitis, the aim of therapy is to prevent progression of disease.