The etiology, diagnosis, and treatment of the infrabony defect. The tooth wall forms the fourth wall. If not, it causes inconsistencies on the bony contour. These defects are often associated with interalveolar bony defects. It is important to give defects their proper names in order to have a better scientific communication.
Inflammation follows the blood vessels into the bone marrow causing bone destruction.
Trauma from occlusion is one of the factors that can direct the destruction of interalveolar bone to one side, but it is not an essential factor. If the marginal bone is thick, a circumferential defect may take place. Usually an intern beveled incision is used. The defect should be curetted out and ostectomy may have to be performed in case of a hemisepted defect. Root planing should not be very aggressive because cementum forms more easily on old cementum than dentin.