Experimental model of oral ulcer in mice: Comparing wound healing in three immunologically distinct animal lines

BACKGROUND: The oral wound healing is dependent of immune participation and the absence or augment of one specific immune profile can delayed wound healing. OBJECTIVES: So, the objective of this study was t evaluate the wound healing of oral traumatic ulcer (OTU) in cheek mucosa of swiss, balb/c and c57bl6J mice. MATERIALS AND METHODS: A total of 144 mice (25-30g) were distributed in three groups: swiss (n = 48), balb/c (n = 48) and c57bl/6j (n = 48). An OTU was performed using a dermatological punch in left cheek mucosa. The animals were euthanized daily (n = 6/group/day by 8 days) for evaluation of the ulcer area, weight loss and histological analysis. RESULTS: There are no differences between ulcer area in three groups; however only swiss group showed total wound healing. Swiss group showed weight loss in 2(nd) and 3(rd) days recovering the body mass in 4(th) day (P < 0.01). Balb/c group showed the greater weight loss (P < 0.05) and c57bl/6j did not show body mass variation (P = 0.258). Histologically swiss group was the only group that showed total reepithelization (P < 0.001). Balb/c (P = 0.022) and c57bl/6j (P < 0.001) showed decrease in histological scores, chronic inflammation on the 8(th) day. Actinomyces was significantly more observed in surface of OTU of balb/c. CONCLUSION: Balb/c mice showed high infection of OTU surface delaying wound healing, and greater weight loss. C57bl/6J mice showed low infection of OTU, but not healing along the eight days. Only the Swiss mice showed wound healing of OTU.