Mouth ulcers well place a little hard may be fibroplasia caused by scarring, can be seen in the recurrent Aphthous ulcer, traumatic ulcers and other diseases, specific as follows. 1. Recurrent Aphthous ulcer: larger and deeper ulcer lesions can have fibroblast proliferation, often leaving a scar after healing, resulting in localized hardness. 2. Traumatic ulcers: chronic ulcer lesions deep with obvious fibroplasia, can form a scar, at the same time, the surrounding tissue high up, curling, there is hyperkeratosis, can lead to localized hardening of the lesion. Mouth ulcers well place a little hard there may be other reasons, it is recommended to go to the hospital in a timely manner, clear cause for targeted treatment.