1. Impaired Chewing Efficiency and Nutrition.
   Lower dentures rest exclusively upon the gum tissue, which is forced to bear the entire load for chewing. The gums themselves are slippery in nature, and since there is little else to keep the denture from moving, chewing usually results in instability of the denture. If you presently wear a full lower denture, you are probably all too familiar with this fact. (When you bite on the right side, the left side pops up; or vice-versa; or when you bite in the front, the back teeth pop up.)
   Due to this instability, lower denture wearers are frequently forced to limit their diets to soft and semi-solid foods, or must cut food into very small pieces in order to eat it.
   
   Additionally, in an effort to minimize the instabilty, denture adhesive is frequently used, but usually with limited success.
   
   
   
2. Jaw Bone Shrinkage (Resorption/Atrophy).
   Over a period of years of wearing a lower denture, the lower jawbone, or mandible, undergoes the shrinkage process of resorption, also called atrophy. A good example of atrophy is seen in muscles which shrink in size due to lack of use. In the case of the mandibular ridge, atrophy is a slow process which occurs due in part to the pressure exerted on the bony ridge which supports the denture, but also due in large part to the decreased function of the bone. (Remember that you typically cannot chew hard foods, therefore the bone shrinks in size due to lack of use; but also this resorptive process is compounded by the downward forces exerted against the bone when chewing.)
   
   Unfortunately, the more bone shrinkage that occurs, the worse the denture fits. This problem seems to be magnified in females by osteoporosis.
   
   
3. Lip Numbness
   The nerves which supply sensation to the lower lip (called the Mental Nerves) exit the lower jawbone on either side of the mandible usually slightly more than an inch from the center of the chin. No matter how much the mandibular ridge resorbs, the nerves stay in the same place. If there is severe atrophy of the mandible, the bony ridge can frequently shrink all of the way down to where the nerves are actually exiting the jawbone on top of the bony ridge, rather than from the side. This presents a significant problem for a lower denture wearer because now the denture actually exerts pressure on the nerve itself when chewing. This pressure on the nerve is manifested as a numbness, tingling, or burning sensation in the lower lip.
   
   
4. Speech Impairment
   Due to the unstable nature of lower plates, patients frequently encounter difficulty speaking. It is no secret that the tongue plays an integral role in speech, and it can become diffucult to articulate words when the tongue is preoccupied holding the lower denture in place.
   

Why Dental Implants?
It is important to recognize that in the vast majority of cases, it is the instability of the lower denture, and not the denture itself which is the root of the problem. For this reason, usually the teeth are not replaced individually using implants, but replaced as a set, using a full lower denture which snaps into place upon several implant posts which protrude through the gums. This is a solid, but removable prosthesis. Replacement teeth can also be made to be non-removable if the patient desires. In either case, dental implants solve almost all of the problems associated with lower dentures. For the present, dental implants will enhance chewing efficiency, nutrition, and speech. And most importantly for the long term, dental implants limit (or even reverse) bone resorption, both because of increased function, and the minimization of pressure exerted on the top of the bony ridge.