Dentures replace missing teeth and provide foundational support for surrounding oral structures. A complete or partial prosthetic rests upon the gum tissue and the underlying jawbone, known as the alveolar ridge. Not wearing dentures initiates a cascade of significant consequences because the prosthetic helps maintain the form of the mouth. The absence of the prosthetic allows the body to interpret the underlying bone structure as no longer necessary, triggering biological changes that permanently alter the oral landscape.
Alveolar Ridge Resorption
The jawbone is a dynamic tissue that requires regular mechanical stimulation to maintain its density and volume. Natural teeth transmit chewing forces deep into the bone, signaling the body to continuously renew and preserve this structure. When teeth are lost, this necessary stimulation ends, and the body begins a process called residual ridge resorption, where the bone is broken down and its minerals are reabsorbed.
Not wearing a denture accelerates this deterioration because no force is being transmitted to the underlying bone. This resorption results in the loss of both vertical height and horizontal width of the residual ridge. Studies indicate that the most rapid loss occurs within the first six months after tooth loss, but the process continues slowly throughout life.
The loss of bone mass can be substantial, with the width of the alveolar ridge shrinking by up to 50% within a year following tooth extraction. This process is progressive and irreversible, meaning the bone tissue that is lost cannot regenerate naturally.
The mandible, or lower jaw, is particularly susceptible to this process, often resorbing at a rate four times faster than the maxilla, or upper jaw. This severe reduction in bone dimension is compounded when the denture is not worn, as the tissue is deprived of any stabilizing load. The resulting change in shape and size of the jawbone is the primary reason an existing denture will quickly cease to fit correctly.
Changes to the Soft Tissue and Mucosa
While the bone beneath the gums shrinks, the soft tissue covering the ridge also undergoes specific negative changes without the consistent support of the denture. The oral mucosa, which contacts the denture base, can become thinner and more delicate, making it easily irritated. This fragility increases the likelihood of developing painful sore spots or minor injuries if the denture is later reintroduced.
A more significant change is the development of a “flabby ridge,” or hypermobile tissue, which is a fibrous, displaceable tissue that replaces the resorbed bone. This condition is a result of soft tissue overgrowth, especially in the upper jaw. The flabby ridge lacks the necessary firmness to provide stable support and can affect up to 24% of maxillae in edentulous patients.
This hyperplastic tissue is highly mobile under pressure, acting like a cushion of loose material. The presence of this unstable tissue makes it difficult for any prosthetic to achieve proper retention or stability. Even if a denture is worn again, the soft, movable foundation prevents it from creating the necessary seal and support for effective function.
Functional and Aesthetic Deterioration
The structural changes in the bone and soft tissue lead directly to a decline in function and a noticeable alteration in facial appearance. A primary functional problem is the significant difficulty in chewing, especially harder or tougher foods, which compromises nutritional intake. Without the denture to restore the proper vertical dimension of the face, the remaining natural teeth, if any, may shift, further complicating chewing mechanics.
Speech can also be impaired, as the tongue relies on the correct contours of the palate and the dental arches for precise articulation. The collapsing bone structure eliminates these anatomical guides, often leading to lisping or slurring sounds.
Aesthetically, the continuing bone loss without the structural replacement of a denture causes a condition often termed “facial collapse.” The loss of underlying bone causes the lips and cheeks to lose their support, leading to a sunken-in appearance. This structural deficit can cause the skin around the mouth and chin to sag and wrinkle prematurely, contributing to a noticeably aged appearance.
Future Denture Fitting and Treatment Needs
The dramatic changes in the oral anatomy that occur when a denture is not worn render the original prosthetic useless. The denture, which was custom-made for the initial ridge contour, no longer matches the shrunken and reshaped jawbone. Wearing the old appliance on a severely resorbed ridge can create chronic pressure points, which accelerate localized bone loss and lead to persistent discomfort.
The poor fit results in an unstable denture that constantly moves during speaking or eating. This lack of retention and stability necessitates professional intervention to restore function. The first step is often a relining or rebasing procedure, where the underside of the existing denture is reshaped to conform to the new, smaller ridge size.
In cases of severe, long-term non-wear, simple relining may not be sufficient to achieve a stable result. The advanced bone loss and hypermobile soft tissue may require more invasive procedures. These can include pre-prosthetic surgery to remove excessive flabby tissue or bone grafting procedures to rebuild the severely diminished ridge height and width, often as a prerequisite for placing dental implants to stabilize a new prosthetic.