Periodontal surgery: From open currettage to mucogingival surgery (Proceedings)

Periodontal surgery involves a special discipline of dentistry that requires extensive flap management techniques. Surgical treatment modalities are directly related to the degree of bone loss, pocket formation, pocket location and the amount of remaining attached gingiva.

Periodontitis begins as an infiltrate subjacent to the epithelium of the gingival margin and rapidly extends throughout the marginal gingiva to affect the connective tissue underlying both the oral and the sulcular epithelium. In addition, there are pathologic alterations of both the sulcular and the oral epithelium of the marginal gingiva. The inflammatory lesion is found throughout the entire thickness of the marginal gingival tissue.

There is a significant correlation between deposit amounts and pocket depths and between deposits and hyperplastic tissues with the additional factor of infection by periodontal pathogens. The size of hyperplastic tissue mass and pocket depth increases concurrently as the disease becomes more severe.

Bone loss begins at the bifurcation of the second premolars and around the first premolars. As the disease progresses, the third and fourth premolars and then the first molars become involved. Bone resorption appears sooner and more severely in the bifurcation regions than interproximally. The first and second premolars are the teeth most frequently lost from periodontitis usually exhibiting bilateral symmetry in the disease process. The predilection for bone loss at the bifurcation region of the premolars may result from the fact that the bifurcation of totally normal teeth is located at the base of the gingival sulcus and is readily accessible.

The clinical features and pathogenesis of periodontitis in dogs is characterized by conversion of the normal gingiva to acutely inflamed, highly vascular, collagen poor granulation tissue. The disease begins as an acute vasculitis upon which a lymphoid cell response becomes superimposed. However, at an early stage, proliferation of the tissues of the gingival margin and the soft tissue wall of the gingival sulcus occurs and enlargement becomes apparent. With the passage of time, this structure, which presents clinically as a rolled margin, enlarges and, in cross section, presents a mushroom-like appearance with a cauliflower-like surface.

The structure is comprised of collagen poor, highly vascular granulation tissue with a dense infiltrate of lymphoid cells and a variable population of PMNs. Vasculitis persists. With time, this structure becomes larger and the residual clinically normal gingival tissue becomes smaller, although in general there is a clear line of demarcation between the normal and the disease tissue. Enlargement continues until no normal gingiva remains. During this process, extensive bone resorption occurs.

The soft tissues behave in one of two ways. Either the hyperplastic granulation tissue remains located near the cemento-enamel junction and a deep periodontal pocket forms comparable to the situation usually seen around human teeth, or the bone resorbs. In cases of the latter type, the disease may progress to the point of tooth exfoliation without significant pocket formation.

Chronic periodontitis does occur spontaneously in dogs maintained on normal diets and in some animals the disease is extremely severe. Periodontal disease is an ongoing process rather than individual stages. A break down as to stages or grades of periodontal disease defines particular problems that occur during the disease process.

A mouth free of periodontal disease has gingival tissue where the gingival margin will be sharp and pink or coral in color. There is normal stippling, which is a pebble like orange peel appearance, absence of marginal exudates, and mouth odor. This is a mouth frequently seen in dogs up to one and one half years of age.

Surgical periodontics

There can be bone loss in dogs and cats without pocket formation. The gingiva follows the loss of bone but maintains the anatomical relationship commonly seen in the premolar area of dogs. Surgical intervention is not indicated here. There is marginal modality to eliminate this condition. This condition requires constant home care and veterinary maintenance - often prophylaxis at two to three month intervals.

When pocket formation exceeds the ability to eliminate the sulcular pathogens on a daily basis to prevent progression of the pocket depth surgical intervention is indicated.

Gingivectomy

The indication for gingivectomy is limited - in cases of pronounced gingival enlargement, shallow suprabony pockets, localized "minor operation", and in combination with flap surgery. It is contraindicated for treatment of infrabony pockets and osseous thickening when attached gingiva is narrow or absent.

Gingivectomy is the removal of gingival pockets by the excision of gingiva. It is also used to recontour the gingival tissue to its proper anatomical form. This procedure is referred to as Gingivoplasty. Gingivectomy or gingivoplasty can be used in combination with other surgical procedures such as flap operations. Gingivectomy is indicated in cases of gingival hyperplasia, shallow suprabony gingival pockets that do not extend beyond the muco-gingival line, while retaining an adequate zone of attached gingiva.

Contraindications include absence of attached gingiva, horizontal or vertical bone loss below the mucogingival junction or line. Gingivectomy can be performed with an electosurgical unit if an abundance of attached gingiva is present. Electrosurgery is best suited for use in cases of gingival hyperplasia where an abundance of gingiva is present and the added benefit of cautery is needed. Most cases of gingivectomy should be performed with sharp dissection.

Mucogingival surgery

Flap procedures with conservative flap reflections are the most universally applicable periodontal surgical modality. It is particularly indicated for treatment of mild to moderate periodontitis.

Mucogingival surgery is performed when there is a need to widen the band of attached gingiva or to cover a denuded root surface. The most common surgical procedures are gingival extension (apically positioned flap) and lateral sliding flap.