Tooth and Bone Loss
Teeth can be lost for a variety of reasons. Anything from disease, injury, birth defect, to decay can result in teeth being lost or removed. However, many dental and health problems can result from tooth loss or removal.

Diet
Without properly aligned teeth an individual might not be able to chew correctly and this may affect their diet. With missing teeth, or no teeth altogether, chewing becomes very difficult or impossible. The diet then becomes restricted to soft, easily chewed foods. This kind of diet may not meet the nutrition needs of the body which can cause constipation, weight loss, arthritis, indigestion, and rheumatism.

Teeth are important to meeting the nutritional needs of the body. And without them, the health of the body may be severely impacted.

Speech

Teeth play a major part in speech. Some letter sounds such as s, z, d, x, n, th, and sh are made with tongue-to-tooth contact. Without teeth, these sounds will not be able to be made easily and may result in a lisp. Lisping can be an embarrassing condition and may make you hard to understand clearly.

The tongue is also affected by lost teeth. With no teeth to keep it in place, the tongue will broaden out and fill in the newly open space. This thickened tongue makes it harder to control and may also result in difficult to understand speech.

Bone Loss in the Jaw

Teeth do more than just chew our food and help us speak. They actually serve to stimulate the bone in the jaw. Each time you chew, the teeth stimulate the bone. Without this natural stimulation, the alveolar bone – the portion of the jawbone that anchors teeth in the mouth – begins to breakdown and is resorbed into the body. Since there are no longer teeth there that “need” the jawbone, the bone deteriorates and goes away.

The rate of deterioration varies per person. However, it can begin almost immediately after a tooth is lost or removed and will continue throughout life. Once deterioration reaches a certain point, dental prosthetics such as dentures will no longer be available to use because there will no longer be enough bone to support them.

Misalignment

Misalignment occurs when teeth no longer have an opposing tooth structure. The tooth with no counterpart can become loose and the bone supporting it may begin to deteriorate because of lack of stimulation. Losing even one tooth may cause the remaining teeth to shift their position, altering an individual's bite pattern and leading to pain in the head, neck and jaw. 

Facial Appearance

Teeth are also designed to hold the lips and cheeks in place. When one or more teeth are missing, the lips and cheeks will not have their natural support system. When closed, the mouth will appear “sunken in” without the support of the teeth. This can age the appearance of the person greatly.