Bone loss can occur if you had advanced periodontal disease or when teeth were removed quite some time ago. It’s quite common to find people who lost teeth many years ago don’t have quite enough bone for dental implants. This is because once tooth roots are removed the bone that used to surround them no longer receive sufficient stimulation to ensure old bone cells are renewed. As a result, bone loss gradually occurs. You may also need a bone graft if you intend to replace upper back teeth that are near the sinus cavities because the bone tends to be naturally thinner in these areas.
Most of the time bone grafting is done at the time of implant surgery as we try to use bone fragments from the implant surgery site. In cases where we need to do a graft from another part of the jaw, it will be done prior to your implant placement as the new bone will need to heal for several months before it is suitable for an implant to go ahead.