Evaluating the implant candidate 241

Fig. 6-51. Severe sickle cell anemia may result in generalized osteoporosis and irregular marrow spaces. (From Schabel, R. W.: Diagnosis of sickle-cell anemia in the prosthetic patient, J. Prosth. Dent. 20:2, 1968.)

crease in bone formation causing displacement of the teeth produces malocclusion. Mandibular changes resulting from greatly increased and altered trabecular patterns complicate the picture. The abnormal growth patterns in both the mandible and maxillae contraindicate implants (Fig. 6-52).

The most serious anemia is aplastic anemia. This condition results from the destruction of the bone marrow. Usually the cause is unknown, but over-doses of radium or radiation, severe infections, or benzene have been known to bring it about. Unless the cause of the condition is removed and the bone marrow restored to normal, the condition is fatal. Again, if the condition is alleviated and the patient

restored to normal with no threat of the condition's recurring, implantation may be allowed.

Agranulocytosis. Agranulocytosis, or granulocytopenia, is associated with a marked leukopenia and accentuated with a disappearance of granulocytes (polymorphonuclear leukocytes) from the circulating blood.

The cause of the disease is difficult to identify, but in most cases it results from the effects of drugs or chemicals on the bone marrow. The resulting lack of granulocytes in the bone marrow, and therefore also in the blood, causes the ready development of local infections that soon become systemic and overwhelming.