Anatomical, histological, and surface ultrastructural evaluation of the palatal mucosa of domestic rabbit (Oryctolagus cuniculus).

The present study investigated the morphology of the palate of rabbit (Oryctolagus cuniculus). Samples from 12 healthy adult rabbits were examined by gross observation, morphometry, scanning electron and light microscopy. The hard palate was elongated and narrowed rostrally. The incisive papilla appeared as a diamond-shaped prominence flanked on both sides by a groove on which a slit-like opening of the nasopalatine duct opened. The palatine raphe was in the form of a groove. On either side of the raphe, 14-16 palatine ridges were present. The direction of these ridges differed according to their position. An incomplete (short) palatine ridge was occasionally present at the caudal part of the hard palate. Several gland openings were scattered on the surface of the palatine ridges. The soft palate extended to about the middle of epiglottis caudally. Its ventral surface had numerous thin transverse mucosal folds separated by furrows, and several openings of glands. Histologically, the incisive papilla, palatine ridges, and soft palate were lined by a parakeratinized stratified squamous epithelium resting on a dense connective layer of lamina propria. The degree of keratinization and the thickness of the lamina propria decreased caudally. Seromucoid glands were present in the rostral and caudal parts of the hard palate, as well as in the soft palate. In conclusion, the palate of rabbit presented characteristic features suggesting functional adaptations for their herbivores diet. Studying the morphological characteristics of the hard and soft palate of rabbits will help veterinary practitioners to investigate pathology malformations and diseases of the oral cavity.