248 Theories and techniques of oral implantology

properly with conventional dentures or removable prostheses. Therefore, the patient can be greatly benefited by an implant-supported fixed denture, no matter how difficult it is to insert and properly fit.

Multiple sclerosis. In multiple sclerosis the tremors appear only during limb movement and disappear when the limb is at rest, although occasionally there may be a static tremor of the head. Such a condition poses no major problems for the implantologist unless the head tremors are present.

Friedreich's ataxia. Friedreich's ataxia is manifested by tremors that resemble those of multiple sclerosis. Because the tremors are limited, implants are usually not contraindicated.

Drug poisoning. Overuse of drugs, accidental or otherwise, often manifests itself with tremors. For example, those people who become dependent on morphine or cocaine often develop tremors of the facial muscles that become more pronounced upon withdrawal of the drug. Chronic mercury poisoning also causes slow tremors that involve the facial muscles as well as the extremities.

Generally the irnplantologist must decide with the patient's physician whether or not the facial tremors are permanent. Permanent tremors usually contraindicate implants. It is also a good idea to avoid implants in patients who are drug addicts, as emotional instability is usually linked to their clinical condition.

Cerebral palsy. Cerebral palsy is usually present from birth and may be caused by a developmental defect or intrauterine cerebral degeneration. Some-times a history of abnormal labor, trauma at birth, neonatal asphyxia, or jaundice has been found in cerebral palsy patients.

The disease is characterized by bilateral, usually symmetric, nonprogressive disturbances of mobility. Spastic weakness of the extremities is the most common manifestation, and it usually involves the legs more than the arms. Involuntary or athetoid movements or cerebellar signs may accompany the spasticity.

The treatment for cerebral palsy includes muscle reeducation whenever possible, speech therapy, and corrective orthopedic procedures. Because many patients cannot handle a removable denture by them-selves, implants may be beneficial in permitting a fixed denture.

Neuritis. Neuritis is the collective name for a group of diseases that are usually degenerative and rarely characterized by signs of inflammation. Neuri

tis may involve a single nerve (mononeuritis) or multiple nerves (polyneuritis), and it is caused by lesions of the nerve roots or of peripheral nerves. These lesions may result from trauma, infection, toxins, or metabolic or vascular disorders.

In mild cases recovery is usually rapid with the proper treatment, but the symptoms can reoccur if the original cause of the condition has not been relieved. If facial nerves are involved and the condition is not controlled, implants may be contraindicated.

Neuralgia. Neuralgia produces paroxysms of acute pain along the branches of a peripheral sensory nerve. It occurs at any age after puberty but is most prevalent in people over 50 years old. The cause is unknown and usually no morphologic changes can be found.

When the trigeminal nerve is involved—a disorder called tic douloureux—the patient suffers brief attacks of severe pain along one or more branches of the nerve. Because the trigeminal nerve supplies the face and jaws, implants are contraindicated. As a general rule, when a patient suffers repeated pain in the jaw or the face as a result of some nervous disorder, it is wise to avoid implants. The pain can be wrongly ascribed to the implants, even though the patient had a previous history of pain from other causes. Also, sudden attacks of pain usually cause grimacing and clenching or grinding of the teeth, which could abuse an implant restoration.

Tumors. Occasionally tumors occur within the connective tissue elements of the nerves. These pro-duce varying symptoms, depending upon their location and size. Benign tumors in locations other than the jaws or skull do not contraindicate implants, since the symptoms do not affect these structures.

Nerve tumors in the jaw may arise from within the inferior dental canal (Fig. 6-56), in the sub-stance of the bone, and beneath the periosteum. The treatment usually consists of surgical removal. If too much bone has been destroyed, implants may be contraindicated. Also, damage to the nerve may contraindicate implants.

Mental attitude. It may seem strange to include mental attitude in a discussion of implant candidacy, but the reasons are quite sound. Dental implantology is a relatively new field, and most patients know this. A person who is overly suspicious or hesitant may later decide that his implants are concern for worry and must be removed, successful or not. Vague complaints that the patient has never felt secure in mind since implantation may lead to