Healing is delayed in oral compared to dermal excisional wounds

Background: Oral wound healing is reported to occur more rapidly than dermal healing due, in part, to factors in saliva that facilitate the repair process. However, the oral environment also presents challenges to healing that include a large commensal flora and trauma from mastication. Methods: Excisional punch biopsies (1.5 mm) were placed in the scalp and hard palate of mice to create similar wounds with an osseous floor and relatively thick connective tissue walls. Histomorphometric analysis of hematoxylin and eosin-stained sections was performed at the widest part of each lesion. Results: The rate of epithelial and connective tissue coverage and the amount of new connective tissue formed were delayed in the oral compared to dermal wounds. In addition, the number of polymorphonuclear leukocytes (PMNs) was significantly higher and more persistent in the oral wounds. Conclusions: Under conditions where a considerable amount of new connective tissue synthesis is required, oral healing is slower than dermal repair. This may be due to a higher degree of inflammatory stimulation induced by conditions present in the oral environment.