The lifetime of the prosthesis depends on the patient’s job and environment. For example, a homebody may have a prosthetic ear that lasts for five or six years, while a farmer or a telephone line worker may need a new one within two years, Dr. Huryn said.
Explore This IssueFebruary 2009
The facial tissues [surrounding the area where the prosthesis will be placed] are captured in dynamic and static states to be sure the prosthesis will sit right, Dr. Huryn explained. The measurements and pattern are stored electronically for future use, but the surrounding tissues may undergo changes over time that call for a new updated moulage (i.e., impression of the patient’s face or missing anatomic defect).
Retention of the Prosthetic Device
Osseointegration is another state-of-the-art advance, explained Gregory G. Gion, MMS, a clinical anaplastologist and founder of Medical Art Prosthetics in Dallas. The ability to anchor prosthetic devices to the bone is the most important prosthetic development over the past few decades, Mr. Gion said.
Adhesives were traditionally used to retain many types of prosthetic devices. Irritation, perspiration, and movement can compromise the bond. Many people will still use adhesives because they may not be candidates for osseointegrated implants or due to reimbursement issues for osseointegration.
People have trouble with the idea of using adhesives. It is time-consuming and must often be done every day. People who depend on adhesives may only wear the device on special occasions, explained Roman Skoracki, MD, Assistant Professor in the Department of Plastic and Reconstructive Surgery at M. D. Anderson Cancer Center in Houston.
Sometimes silicon pieces impregnated with magnets can be used to retain the prosthesis, but osseointegration offers the most secure option. In osseointegration, titanium screws are placed surgically into the craniofacial skeleton, and posts or magnets are screwed into the top of these screws. Magnets that attach to these abutments are placed on the prosthetic device. In the cancer setting, the titanium screws can be implanted into the bone by the plastic surgeon or oral and maxillofacial surgeon after the surgical site has been prepared by an ablative surgeon.
Replacing defective intraoral structures requires the skill of a maxillofacial prosthodontist. Dr. Davis explained the typical procedures for intraoral prostheses.
For patients who have lost a portion of the hard palate, an obturator will enhance functional outcomes of speech, swallowing, and chewing. When the mandible is resected for cancer, a free tissue transfer with the fibula allows placement of dental implants. A resection appliance supported by dental implants replaces the lost dentition, she said.