How does bone loss after tooth extraction occur?

Lost stimulation. After extraction, the aveolar bone lost the stimulation from the tooth movement and starts resorption. It is kind like atrophy. Reserach showed, the surounding bone can lost 60-80 percent of its volume at the end of first year after extraction. To prevent bone loss after extraction, you should get bone grafting at the time of extraction. After 4-6 month, implant can be placed.
Lack of use. The bone will slowly resorb if no tooth is present. If you don't use it you lose it! a bone graft and a dental implant will prevent bone loss.
Infection. Tooth extraction may lead to more bone loss if the area of extraction is severly infected or inflammed. This is the reason why we should clean the area and prescribed antibiotic to treat the acute infection prior to extraction. Secondly, bone socket fracture also may lead to osteonecrosis and bone loss. Lastly, bisphosphonates (osteoporosis meds) cause onj and bone loss after extraction.

Related Questions

Is it possible to have bone loss from tooth extractions?

Yes.. Following a tooth extraction there is almost always some bone loss. If the bone was in good shape prior to the extraction then you won't see much, but if the tooth was troubled with infections or something then more bone loss can be expected. Keep in mind..The bone can be replaced quite often at the same appointment of the extraction. Read more...
Absolutely. You will have bone loss after the tooth is removed. If you don't use the bone, you loose it. Consider a dental implant to replace the tooth/teeth. Dental implants maintain your bone volume in the jaw bone. Read more...