234 Theories and techniques of oral implantology

Fig. 6-41. Instead of the cotton-wool appearance, the maxillae may also look dense and granular in Paget's disease. (From Bhaskar, S. N.: Synopsis of oral pathology, ed. 3, St. Louis, 1969, The C. V. Mosby Co.)

Fig. 6-42. The mandible is involved less frequently than the maxillae in Paget's disease. When affected, its trabeculae typically become coarse and longitudinally oriented. (From Worth, H. M.: Principles and practice of oral radiographic interpretation. Copyright 1963 by Year Book Medical Publishers, Inc. Used by permission.)

have been caused by a general overgrowth of the bone, radiographs will reveal that there is very little bone structure present.

The cause of osteitis deformans is unknown, but it usually occurs after the age of 40 and is most common after the age of 60. It is often associated with diabetes mellitus, and subsequent bone sarcomas are not unusual. The onset of the condition is insidious. If there is pain, it is usually in the long bones of the legs or occurs in the skull as a head-ache. Although the disease itself is not fatal, the patient may succumb to such complications as spontaneous fractures, secondary anemia, or bone sarcomas.

There is no specific therapy or treatment for the disease. Orthopedic exercises sometimes help when long bones are affected, with the use of orthopedic

appliances when needed. Eventually, however, the deformities may lead to invalidism. Because spontaneous fractures are not uncommon, it is inadvisable to insert dental implants in a person suffering from osteitis deformans. Also, because the disease is progressive, it is very difficult to ensure that a pros-thesis fabricated when the patient is first seen will fit months later. In addition, as the bone becomes less dense, it is difficult to find a site suitable for a post type implant or a triplant. Thus a patient with osteitis deformans is rarely an implant candidate.

Other diseases causing bone deformities

Leontiasis ossea (leontiasis ossium). Leontiasis ossea is a disease characterized by bilateral enlargement of the facial bone. The patient has a lion-like appearance since the normal depressions on the face and around the nose are filled in by the thickening of the labial surfaces of the maxillary, molar, and nasal bones and some portions of the frontal bones. It has been found, however, that most patients with a leonine face can also have Paget's disease (osteitis deformans) or fibrous dysplasia.

The underlying pathologic process of leontiasis ossea is unknown. Radiologically, the thickened bone is seen to be greatly increased in density. However, other than the bone structure, which shows a homogenous granularity throughout, there may be complete absence of any pattern, so that the structure-less density resembles the chalk-like appearances of some cases of osteopetrosis.

Blindness can occur from compression of the optic nerve or of the eyeball caused by a reduction in size of the orbits. The nasal passages become constricted by the thickening of the neighboring bones, making it difficult to breathe. Because the mandibular bone often becomes thickened, there may be too little space for the tongue. Deafness and other symp-