Evaluating the implant candidate 239

sites are the pelvis, spine, and ribs. The cause is unknown. The lesion (or lesions, since they are frequently multiple) is 'well defined, consisting of destroyed bone being replaced by plasma cells. Treatment can only relieve pain and delay the disease's progress.

When contemplating implants in a patient with a bone malignancy, the implantologist must work closely with the physician treating the patient. Even when a cure or long-term regression is effected, the patient may be undergoing treatment that contra-indicates implants. In cases where, despite treatment, there is no cure, the patient's comfort in chewing and appearance are important considerations, and implants may be very useful. Although Linkow's experiences in using implants in head and neck patients who have undergone extensive resections is limited, implants seem promising not only to sup-port a fixed prosthesis but perhaps also to aid in other plastic surgical restorations.

Hodgkin's disease (malignant lymphoma, lymphadenoma). Bones are often involved in Hodgkin's disease and in practically all terminal cases the bone marrow becomes involved. Although it may affect any bone in the skeleton, this disease rarely involves the jaws. When it does involve the bone, it usually occurs as a result of metastatic dissemination and produces a radiolucent area with well-defined margins that suggest infiltration of the bone. The appearances are very similar to most other osteolytic malignant tumors.

Radiologically, three different appearances can be associated with Hodgkin's disease in bone: bone destruction per se, bone destruction with bone formation, or bone formation alone.

With control of the disease, the whole area may heal, but usually with some slight sclerosis. In any event, patients with Hodgkin's disease must be contraindicated for implants.

Blood diseases

A thorough diagnosis of an implant candidate should include questions about previous blood dyscrasias and an examination for any current condition. The gingival tissues often reveal the early stages of various types of blood disturbances, and it is important not to confuse locally caused peridontal disease with the oral symptoms of systemic diseases. Anemia, polycythemia, purpura, leukemia, granulocytopenia, and other diseases are sometimes first discovered by the dentist because of characteristic changes in the oral or periodontal tissues. A rapid

hyperplasia, edema, unusual bleeding, and pallid mucosal tissues are suspicious signs, especially when accompanied by petechiae on the palate or other surface tissues. Systemic checkups with blood counts and other tests are advisable whenever the dentist has any doubts.

There are some blood dyscrasias, such as hemophilia and leukemia, that always contraindicate the introduction of implants. Other types of blood disease, such as those resulting from acute infections that can be successfully alleviated, allow the introduction of implants at a later date.

The following group of conditions is only partially representative of the wide range of diseases affecting the blood.

Anemias. Anemia is any condition in which the blood does not contain an adequate number of normal red blood cells or in which the red blood cells do not contain an adequate amount of hemoglobin. Anemias may be caused by defective formation of the cells, cell destruction, or excessive loss of the cells from the body. Because the blood is unable to supply the tissues with adequate nourishment, all anemias are characterized by fatigue, weakness, and

Fig. 6-50. In anemia, the soft tissues are markedly pallid. When anemia is suspected from the condition of the oral tissues, it is a good idea to check the eyes for additional signs.