242 Theories and techniques of oral implantology

Fig. 6-52. As a result of erythroblastic anemia, bone formation increases, causing displacement of the teeth and malocclusion. (From Worth, H. M.: Principles and practice of oral radiographic interpretation. Copyright 1963 by Year Book Medical Publishers, Inc. Used by permission.)

Signs of the condition include fatigue and extreme weakness, followed by malaise, chills, fever, and a rapid but weak pulse rate. The throat is swollen and inflamed, and dysphagia and ulcers of the oral mucosa are typical. The bone supporting the teeth is sometimes rapidly destroyed, leaving the teeth supported only by soft tissues. Unless success-fully treated, the patient becomes acutely ill, with necrotizing ulcers of the pharyngeal and buccal mucosae. Prostration becomes extreme, often with regional lymphadenopathy, and death results in a few clays.

Because local minor infections may result from an implant procedure, implants are contraindicated for those patients taking drugs known to sometimes produce the disease, such as sulfonamides, antithyroid drugs, ataractic agents, and nitrogen mustards. Also, because x-rays can damage bone marrow and

cause agranulocytosis, implants are contraindicated for those patients undergoing radiation therapy.

Leukemia. Leukemia may be regarded as a cancer of the blood-forming organs characterized by a permanent increase in the leukocytes of the blood. Its cause in man is unknown, but sometimes the patient has a history of exposure to x-rays, radioactive materials, and certain chemicals, such as benzene.

Leukemia can involve any of the different kinds of blood cells, such as granulocytes, lymphocytes, monocytes, and primitive white (stem) cells. Some of the less common varieties of leukemia are eosinophilic leukemia, basophilic leukemia, megakaryocytic leukemia, reticulum leukemia, plasma cell leukemia, and erythroleukemia.

Neoplastic cells arising from the bone marrow, lymph nodes, or other hemopoeitic areas—including the spleen, liver, and thymus—proliferate and are then probably disseminated through the bloodstream to lodge in blood-forming tissues, where they continue their proliferative activity. In the more acute forms of leukemia, they also infiltrate many of the body tissues. Proliferation of these neoplastic cells causes hyperplasia of the bone marrow and enlargement of the spleen, liver, and lymph nodes. This results in the crowding out of the normal blood-forming elements. Consequently, anemia occurs with increased susceptibility to infection because of the impairment of the defense mechanisms normally present in blood.

Successful treatment usually inhibits the proliferation of neoplastic cells, reduces the number of white blood cells, and also reduces the size of the involved organs. Normal hemopoiesis may reoccur, although some evidence of the disease usually persists.

Broadly categorized, there are two types of leukemia: acute and chronic. Acute leukemia usually occurs in young children and is more common in boys than in girls. It usually begins suddenly, with high fever, secondary infections, joint pains, and bleeding from the mouth, nose, kidneys, and bowel. It is characterized by the replacement of normal bone marrow by primitive or stem cells of the blood-forming series. Various methods of treatment may temporarily eliminate the great majority of neoplastic cells, thus restoring the bone marrow to normal activity and the patient to normal health. The patient, however, requires close and frequent observation, and improvement is measured in months to a few years, since resistance to treatment almost invariably develops.