Evaluating the implant candidate 247

upon the needs of the patient, and response may be slow.

Vitamin B, (riboflavin) deficiency. Riboflavin is essential for proper growth and tissue function, and a deficiency of it results from an inadequate animal protein consumption, chronic diarrhea, liver disease, or chronic alcoholism. After surgery it sometimes occurs when dextrose infusions are given without vitamin therapy.

Deficiency symptoms may be confused in the edentulous patient. Angular stomatitis, dermatitis, and fissures in such patients may result from a riboflavin deficiency or loose-fitting dentures. However, if the symptoms are caused by a deficiency, they are accompanied by seborrheic dermatitis about the nose and ears and eye lesions. In the mouth, a recession and loss of normal stippling of the gingiva or a magenta-colored opalescent sheen on the buccal mucosa and atrophy of the fungiform papillae of the tongue may be found. The tongue itself may be magenta in color.

Treatment consists of supplementing the diet with riboflavin, usually administered orally.

Vitamin B1 (thiamine) deficiency. The proper metabolism of carbohydrates and the normal functioning of the nerve tissues depend upon thiamine. In most people, a deficiency results when the amount of thiamine in the diet is not adequate. Hyperthyroidism, pregnancy, lactation, fever, and pro-longed diarrheas demand increased amounts in the diet, as do diseases causing impaired vitamin utilization.

Symptoms of a thiamine deficiency include anorexia, irritability, emotional instability, disturbed sleep, generalized abdominal complaints, and constipation. In the mouth erythema, a loss of stippling of the gingiva, and pinpoint vesicles on the buccal mucosa occur. The tongue exhibits enlarged and prominent fungiform papillae. Eventually edema, serous effusions, and changes in the heart and central nervous system occur. The disease is then called beriberi.

If diagnosed fairly early, the disease responds well. However, in an advanced stage of thiamine deficiency, diagnosis is often impossible.

Calcium deficiency. A deficiency of calcium is rarely caused by an inadequate amount of calcium in the diet; rather, it results from the inadequate absorption of calcium from the intestine   a vitamin D—linked syndrome. If vitamin D is deficient or the calcium intake very low, calcium is withdrawn from the bone. Hyperparathyroid activity, pregnancy, lac-

tation, rapid bone formation, and osteoblastic metastases will draw calcium from bone. When a bone is immobilized or diseased (osteitis deformans and malignant neoplasms), it tends to give up calcium.

Temporary losses of calcium from the bone may be reduced by increasing the ingestion of calcium, such as during pregnancy. It is best to postpone an implantation until the condition causing the calcium withdrawal is over or until the loss is well compensated. Severe disorders, such as osteoblastic metastases, are always contraindications for implants.

Iron deficiency. The most outstanding condition caused by an iron deficiency is a chronic anemia characterized by small, pale red blood cells and by low reticulocyte activity. For adults such an anemia is rarely caused solely by an iron-poor diet but by some condition resulting in a depletion of the body's iron. Among these conditions are gastrointestinal disorders, pregnancy, and excessive blood loss caused by heavy or frequent menses. (See also Anemia, p. 239.)

Nervous disorders

Nervous disorders should not be overlooked or underestimated in evaluating an implant candidate. Some nervous disorders, such as headaches and similar recurrent but minor ailments, are usually not too serious and do not contraindicate implants. However, cerebral disorders characterized by uncontrollable in-voluntary movements usually do contraindicate implant insertion. Any patient suffering from a disorder whose symptoms include sudden, recurrent attacks involving a loss of consciousness or changes in motor activity or sensory phenomena is a poor risk. During surgery he might go into convulsions or stiffer other violent symptoms of his disorder, making implant insertion difficult or hazardous. If the implants have already been inserted in such a patient, his seizure may involve clenching and grinding of the teeth, which place abnormal stress on the implants and can easily destroy the implant system.

Parkinson's disease. Parkinson's disease is a disorder of the central nervous system characterized by frequent involuntary tremors. The tremors are most obvious in the head, eyelids, tongue, fingers, and forearm. Deciding whether or not to use implants in such a patient may be a real dilemma for the implantologist. It is often very difficult to insert implants and make accurate models for dental prostheses in such a patient. However, it is also very difficult for some of these victims to masticate their food