The main reason for the whitening and hardening of the wound after biting the inner wall of the oral cavity is the formation of local mucosal scarring and keratinization of the mucosa. 1. After oral mucosal injury, its pathological changes are mucosal local tissue deterioration, exudation and local scarring hyperplasia, mucosal inflammatory exudation is caused by cellular rupture of local tissue inflammatory lesions, through the internal and external cellular fluid exchange exudate to the tissue surface, and then form a white pseudomembrane covering the surface. 2. Inflammatory cell proliferation proliferation process has a certain role in the protection of the body, inflammatory lesions stimulate the body to produce a protective effect of the body, the local proliferation changes in the normal metabolism of cells. If there is an oral mucosal lesion, it is recommended that the patient consult a doctor in a timely manner, do not be negligent, so as not to delay the condition.