Teeth are anchored to the jaw by the alveolar bone, otherwise known as the tooth socket. This anchoring gives teeth the strength to support the pressure of chewing. The alveolus is the part of the alveolar bone that encases the root. A tissue called cementum at the base of the root holds a tooth to the alveolar bone. The upper jaw (maxilla) and lower jaw (mandible) both contain alveolar bone. A ligament holds the teeth in place and provides additional support.
Dental problems and habits can lead to the loss of alveolar bone over time. This can cause the bone to resorb, or dissolve, and can eventually lead to tooth loss if it is not treated.
If a tooth is extracted and not replaced, the jawbone can deteriorate. Natural teeth stimulate the jawbone through chewing and biting. If a tooth is missing, the alveolar bone no longer receives stimulation in that area, which can cause the jawbone to resorb. The rate and amount of deterioration varies from person to person. It is worst in the first 18 months and continues throughout life.
Gingivitis and periodontitis are gum diseases caused by plaque, a sticky, colorless film caused by food particles and bacteria that adhere to teeth at and below the gum line. Untreated gum disease can lead to pockets, or spaces, where the gums separate from the teeth. If gingivitis progresses to periodontitis, the gum tissue and alveolar bone can deteriorate, which can lead to tooth loss.
Unanchored dentures are placed on top of the gums and do not stimulate the alveolar bone. This lack of stimulation can cause the bone to resorb over time, which can lead to loosening of the dentures and problems eating and speaking. It may become impossible to hold dentures in place, even with strong adhesives, and a new set may be needed. Some dentures are supported by anchors that stimulate and preserve alveolar bone.
With a bridge, the area without a natural tooth does not receive stimulation in the alveolar bone. This can be corrected with a bone graft procedure.
If a tooth is knocked out or broken, that can lead to bone deterioration. A bone grafting procedure can restore function and promote new bone growth.
If teeth are misaligned, a tooth without an opposing tooth structure can over-erupt and cause deterioration of the alveolar bone. TMJ problems, normal wear and tear, and lack of treatment can also contribute to bone deterioration.
Osteomyelitis is a bacterial infection that affects the jawbone and bone marrow. It can lead to inflammation and a reduction in blood flow to the bone. The condition usually requires antibiotics, removal of the affected bone, and a bone graft.
Both benign and malignant facial tumors generally require removal of a section of the jawbone and reconstructive bone grafting.
Some birth defects cause missing portions of teeth, facial bones, jawbone, or skull. A bone graft can be used to treat these conditions.
If the upper molars are removed, air pressure from the maxillary sinus can cause resorption of bone. This can lead to enlargement of the sinuses, or hyperneumatized sinus, a condition that can be treated with a procedure called a sinus life.