Wearing old complete dentures can be the cause of various disorders of the stomatognathic system in many patients, including, among others: pain, chewing difficulties, prosthetic instability and aesthetic problems. On examination, the most frequent problems turn out to be related to lesions mainly affecting the fibromucosa, which leads the practitioner to first carry out a preliminary treatment at this level before making a new prosthesis. Thus, this work will describe the most frequent lesions, their etiologies, and the most adapted therapeutic solutions.