Epithelium and connective tissue regeneration during palatal wound healing in desalivated rats--a comparative study

Reduction of salivary secretion leads to alteration in the physiologic functions of saliva, including the effect on wound healing. The present study evaluates epithelial regeneration as compared with new connective tissue formation during the healing of a palatal wound in a desalivated rat model. Experimental rats underwent sialadenectomy of the submandibular and sublingual glands and ligation of the parotid ducts. Small or large mucoperiosteal circular wounds, 3 mm or 5 mm in diameter respectively, were produced in the palate. The distance between epithelial margins and the amount of myofibroblasts were determined at 0, 3, 7, 14, 21 and 28 days post-surgery. The distance between epithelial margins of the small wound (3 mm) was similar in experimental and control groups; however, the distance in the large wound (5 mm) was greater (P < 0.001-0.05) in experimental rats. New connective tissue formation, as indicated by the amount of myofibroblasts, was less (P < 0.01-0.05) in desalivated rats with either the small or the large wound between days 3 and 14. The present results indicate that there is a tissue-specific effect of desalivation, and connective tissue is much more sensitive to desalivation than epithelium.