Chronic mucogingival defects in miniature swine

Controversy surrounds the importance of keratinized gingiva in maintaining periodontal health. A well-defined animal model system is necessary to evaluate longitudinally the role of keratinized gingiva when plaque control is inadequate or where dental procedures (restorative, prosthetic or orthodontic) alter the periodontal environment. Facial gingiva was excised from eight primary incisors in miniature swine. Contralateral teeth were used as controls. The experimental teeth exhibited mucogingival defects at 3 and 6 month observation periods. The secondary teeth erupting into the experimental regions also exhibited recession and chronic mucogingival defects. The marginal tissue in regions devoid of keratinized gingiva demonstrated clinical signs of inflammation. No progressive gingival recession was present. Excision of keratinized gingiva to produce mucogingival defects in swine provides a convenient model system for evaluating the effect of dental procedures on periodontal health where little or no keratinized gingiva is present.