A 57-year-old female patient was evaluated for an unstable maxillary dental prosthesis. The patient stated that approximately 2 weeks prior to this consultation the prosthesis was relined four times. Despite this, it often had a tendency to shift during meals. On the other hand, she is very satisfied with a complete fixed prosthesis on implants in the mandibular arch. She has been wearing this latter lower prosthesis for the same length of time as the upper prosthesis. She indicated that a similar problem existed with the former upper prosthesis, resulting in her consulting a prosthodontist.