Nonneoplastic diseases of bone that affect the maxilla and mandible fall into multiple categories. Inherited diseases that affect bone are discussed in Chapter 6, and benign and malignant neoplasms of bone are discussed in Chapter 7. The purpose of this chapter is to delineate several other nonneoplastic diseases of bone that are important for a dental hygienist to understand but are not covered elsewhere in this text. These include three forms of cemento-osseous dysplasia: (1) periapical, (2) florid, and (3) focal. In addition, the dental hygienist should also be familiar with the various types of fibrous dysplasia and the clinical and radiographic features of Paget disease, central giant cell granuloma, aneurysmal bone cyst, and osteomalacia.
The term dysplasia, as used in this chapter in the context of the cemento-osseous dysplasias and fibrous dysplasia, refers to the abnormal and disordered production of cementum and bone. This term in this context should not be confused with dysplasia as used in the context of epithelial dysplasia. Epithelial dysplasia connotes a premalignant condition affecting squamous epithelium.
Benign fibro-osseous lesions that affect the maxilla and mandible include central and peripheral cementifying and ossifying fibromas, periapical cemento-osseous dysplasia, florid cemento-osseous dysplasia, focal cemento-osseous dysplasia, and fibrous dysplasia (Box 8-1).
Periapical cemento-osseous dysplasia is a relatively common disease of unknown cause that affects periapical bone (Figure 8-1, A and B). The term cementoma was used in the past for this disease. However, because the disease does not represent a neoplasm, this term is inappropriate and should be avoided.
The lesion is asymptomatic and is discovered on routine radiographic examination. It occurs most commonly in the anterior mandible of patients older than 30 years of age. It is more common in women than men. Most studies have shown a predilection for this disease in black women. Early lesions are well circumscribed and radiolucent and may mimic periapical inflammatory disease. The bone at the apical area of multiple teeth may be involved. Teeth in the affected area are vital unless they are coincidentally carious or have been traumatized. With time the lesions become increasingly calcified; therefore, older lesions are increasingly radiopaque and may appear radiolucent with central opacifications.
The diagnosis of periapical cemento-osseous dysplasia is usually established on the basis of its characteristic clinical and radiographic features. Historical and clinical information and radiographic appearance are both important in establishing the diagnosis. Pulp testing confirms that teeth are vital. A biopsy may be necessary in cases in which the characteristic radiographic features are not evident. Microscopic examination reveals a fibro-osseous lesion. Like other fibro-osseous lesions, periapical cemento-osseous dysplasia is composed of a combination of fibrous tissue and calcifications. The calcifications in this lesion may resemble bone, cementum, or both. Early lesions consist mainly of fibrous tissue, whereas long-standing lesions contain fibrous connective tissue interspersed with numerous calcifications (Figure 8-1, C). If a patient demonstrates radiographic changes characteristic of an early lesion, follow-up examinations may be necessary to ensure that a correct diagnosis was established. Once the condition is recognized, no treatment is necessary. The lesion remains asymptomatic and localized.
Florid cemento-osseous dysplasia is another fibro-osseous lesion characterized by disordered cementum and bone development. This lesion characteristically involves multiple quadrants in the maxilla and mandible.
Florid cemento-osseous dysplasia occurs most often in black women older than 40 years of age. The cause of this disease is unknown. Radiographically, it differs in location from periapical cemento-osseous dysplasia in that it typically affects more than one quadrant of the maxilla and mandible, often in the posterior areas. On occasion, an early radiolucent phase similar to that seen in periapical cemento-osseous dysplasia may be identified. However, the majority of cases present as radiopaque masses of irregular opacification (Figure 8-2). There is usually no bone expansion.
Florid cemento-osseous dysplasia is best diagnosed on the basis of its characteristic patient history, clinical presentation, and radiographic appearance. Because of these findings, treatment is often unnecessary. However, in an edentulous patient the sclerotic masses may perforate the mucosa, resulting in a communication between the oral environment and the underlying bone. This complication may lead to the development of osteomyelitis, resulting in pain and swelling. In these cases, antibiotic therapy and surgical intervention are needed.
Focal cemento-osseous dysplasia is an asymptomatic fibro-osseous lesion that shares similar microscopic features with periapical cemento-osseous dysplasia and florid cemento-osseous dysplasia. However, it differs from these two lesions in that it has unique clinical and radiographic features.
Focal cemento-osseous dysplasia usually occurs in women between 30 and 50 years of age; and, unlike periapical and florid cemento-osseous dysplasia, it is reported to be more common in white than black individuals. It typically arises in the posterior mandible and appears as an isolated, well-delineated radiolucent-to-radiopaque lesion that is less than 1.5 cm in size.
Biopsy and microscopic examination usually are necessary to establish a diagnosis of focal cemento-osseous dysplasia. A characteristic surgical feature of focal cemento-osseous dysplasia is that it is composed of numerous gritty pieces of soft and hard tissue. This finding is distinctly different from the characteristic surgical features of a central cementifying or ossifying fibroma. These latter tumors present as a well circumscribed mass of hard tissue that separates easily from the adjacent normal bone. The gritty tissue removed from focal cemento-osseous dysplasia represents fibrous connective tissue interspersed with bone trabeculae and cementum-like material. Once a definitive diagnosis has been established, no further treatment is necessary. The prognosis for focal cemento-osseous dysplasia is excellent. On occasion, a focal lesion has progressed to florid cemento-osseous dysplasia.
Fibrous dysplasia is a disease that is characterized by the replacement of bone with abnormal fibrous connective tissue interspersed with varying amounts of calcified material. Although the cause is unknown, several theories have been proposed. One of the most widely accepted theories is that the unusual fibrous proliferation is the result of abnormal mesenchymal cell function. Several types of fibrous dysplasia exist; each type shares similar microscopic features, but the clinical presentation and associated systemic signs and symptoms differ. Microscopically, fibrous dysplasia is classified as a benign fibro-osseous lesion. It is composed of vascularized, cellular fibrous connective tissue interspersed with irregular trabeculae of bone emerging from the connective tissue.
Monostotic fibrous dysplasia, the most common type of fibrous dysplasia, is characterized by involvement of a single bone. The mandible and maxilla are commonly affected, and the maxilla is more frequently involved than the mandible. Other bones may be affected, including the ribs, femur, and tibia. Monostotic fibrous dysplasia is most commonly diagnosed in children and young adults; no sex predilection is seen. Clinical examination reveals a painless swelling or bulging of the buccal plate of the maxilla or mandible. The expanding nature of the lesion may lead to malocclusion, tipping, or displacement of adjacent teeth. However, the teeth are rarely mobile.
Polyostotic fibrous dysplasia is characterized by involvement of more than one bone. It typically occurs in children, and a definite female gender predilection is seen. The skull, clavicles, and long bones are often affected, and most cases are asymptomatic. When the long bones are involved, they may exhibit bowing and an associated dull aching pain. Patients with polyostotic fibrous dysplasia often demonstrate skin lesions. These lesions appear as light-brown macules called café au lait spots. Several forms of polyostotic fibrous dysplasia exist. Craniofacial fibrous dysplasia is the term used for polyostotic fibrous dysplasia that involves the maxilla with extension into the sinuses and adjacent zygoma, sphenoid, and occipital bones. Another form of polyostotic fibrous dysplasia is called the Jaffe type (or Jaffe-Lichtenstein type). It involves multiple bones along with associated café au lait macules on the skin. The most severe form of polyostotic fibrous dysplasia is called Albright syndrome (or McCune-Albright syndrome). This condition is characterized by endocrine abnormalities, including precocious (early) puberty in females, and stunting or deformity of skeletal growth in both sexes as a result of early epiphyseal plate closure. Precocious puberty is exhibited by menses, pubic hair, and breast development in children as young as 2 years of age. Other complications of Albright syndrome include diabetes mellitus and hyperthyroidism. Café au lait skin macules may occur in this form of polyostotic fibrous dysplasia.
Clinical examination reveals a painless enlargement of the affected bone or bones. Jaw involvement typically appears as a painless, progressive, unilateral enlargement of the maxilla or mandible. When fibrous dysplasia involves the maxilla, the disease usually extends into the maxillary sinuses. Involvement of the jaws may occur in any type of fibrous dysplasia. The classic radiographic appearance of fibrous dysplasia is a diffuse radiopacity that is described as resembling “ground glass” (Figure 8-3, A). The abnormal bone blends into the adjacent normal bone, making it difficult to determine the periphery of the lesion. A patchy radiolucency with central opacifications and a dense radiopacity have also been observed in fibrous dysplasia. The radiolucent or radiopaque appearance of fibrous dysplasia depends o/>