The patient visited for swell and ache of sublingual region. The patient′s two sides of sublingual glands were swelled. The mandibular central incisors were repaired by the ill fitting prosthesis, and there was an irregular oral ulcer under it. The area of the ulcer was about 2 mm×2 mm. The sublingual glands recovered in two days after the ill fitting prosthesis of mandibular central incisors was removed away, iodoglycerin was applied on the oral ulcer, vitamin B1, vitamin B2, prednisone and amoxicillin was taken.