Evaluating the implant candidate 249

unpleasant encounters, at the very least. A hesitant patient should never be bulldozed into accepting implants, even when the dentist feels sure that the candidate is ideal in every other way. Facts about implant procedures, alternative procedures, and the patient's prognosis   with or without implants--
should be explained. After the patient understands what is involved, the decision should be up to him.

When dealing with patients who are known to be severely neurotic or psychotic, the dentist may or may not choose to perform an implantation. Such patients have a wide range of syndromes, some of which would not be affected by a dental implant procedure. Indeed, the cosmetic improvement might be beneficial. However, those patients who habitually clench or grind the teeth, gnaw on pencils, pipes, or other objects, and are prone to grimacing and muscle spasms should be avoided. If the patient is under psychiatric treatment, the psychiatrist might be consulted with the patient's consent before making a decision.

If while questioning a patient it appears that he or----usually   she changes doctors frequently or
has a long list of vague symptoms, the dentist might well suspect hypochondria. Such a patient is a poor candidate. In an implant procedure she may well find a focal point for her complaints or invent a new set of symptoms suitable to the occasion. While the new source of attention may be a boon to such a patient, it can be a bother to a busy practitioner.

Aside from the more obvious symptoms of mental

illness, such as exaggerated suspicion, extreme nervousness or fear, and great excitability or anxiety without apparent cause, few dentists are able to recognize emotional instability nor would they presume to label it so. If the patient has been seen several times before and his responses to treatment have been favorable, it may be assumed that he will respond well emotionally to implant procedures. If the patient is new, the practitioner may find it well worth a few additional minutes of his time to ask the patient how he feels about the subject of implants in general, dental implants in particular, and what he hopes to gain from a dental implantation. If the patient is confident and optimistic, he is usually an acceptable candidate.

RADIOGRAPHIC CLASSIFICATION OF IMPLANT CANDIDATES

Assuming that the patient has no systemic or local conditions that would contraindicate implants, the remaining qualification for implant candidacy is the amount of alveolar bone left in the intended site or sites. The amount of bone between the crest and a vital anatomic landmark determines whether the implant will be endosseous or subperiosteal. The nature of this bone   either dense or porous—decides the implant design. In some situations there will be enough bone flanking a landmark for use as an implant site, even if sufficient height is lacking.

The standard method of evaluating the amount of bone and its character is, of course, radiographic

Fig. 6-56. This patient, who had numerous other neurofibromatous lesions elsewhere in his body, also had a large neurofibroma within the mandibular dental canal. (From Worth, H. M.: Principles and practice of oral radiographic interpretation. Copyright 1963 by Year Book Medical Publishers, Inc. Used by permission.)