abnormalities of bone Flashcards
What is a focal osteoporotic marrow defect?
An area of hematopoietic marrow sufficient in size to produce a radiolucency.
What does a focal osteoporotic marrow defect mimic?
Pathology.
Where is a focal osteoporotic marrow defect typically located?
Posterior mandible.
What is idiopathic osteosclerosis?
A focal increase in bone density.
What does idiopathic osteosclerosis appear as?
Dense bone islands.
Where is idiopathic osteosclerosis located?
Mandible.
Is idiopathic osteosclerosis expansile?
Non-expansile.
What is a simple bone cyst?
A benign empty or fluid-filled cavity.
Is a simple bone cyst a true cyst?
Not a true cyst.
What radiographic appearance is associated with simple bone cyst?
Scalloping between roots.
What is a central giant cell granuloma?
Destructive lesions of the jaw comprised of osteoclast giant cells.
Where is a central giant cell granuloma typically located?
Mandible, anterior to the first molar.
Can a central giant cell granuloma cross the midline?
Yes, it may cross the midline.
What is cherubism?
A rare autosomal dominant condition.
What are the characteristics of cherubism?
Bilateral expansion in the posterior mandible.
What is the typical disease course of Cherubism?
Remission and involution after puberty.
What are the types of benign fibro-osseous lesions?
Cemento-osseous dysplasia, including peri-apical, focal, and florid cemento-osseous dysplasia, and fibrous dysplasia.
Where does Peri-apical cemento-osseous dysplasia occur and in whom?
Anterior mandible, black females.
Where does focal cemento-osseous dysplasia occur?
Posterior mandible and is solitary.
Where does florid cemento-osseous dysplasia occur?
Multifocal involvement, often symmetric in all four quadrants.
What are the stages of benign fibro-osseous lesions?
Fibroblastic early stage progressing to a later stage with bone deposition.
What is the treatment for benign fibro-osseous lesions?
No treatment is needed.
Is it safe to place implants in areas of benign fibro-osseous lesions?
Do not place implants in areas of lesions.
What gene is mutated in fibrous dysplasia?
Postzygotic mutation of the GNAS1 gene.
What is monostotic fibrous dysplasia?
Enlargement of a single bone, often the maxilla, with ground-glass opacification.
What syndromes are associated with fibrous dysplasia?
Jaffe-Lichtenstein and McCune-Albright syndrome, associated with café au lait spots.
What is Mazabraud syndrome?
Fibrous dysplasia + myxomas.
What radiographic appearance is associated with fibrous dysplasia?
Chinese character bone.
What is an ossifying fibroma?
A neoplasm of fibro-osseous differentiation.
Where is ossifying fibroma typically located?
Mandibular molar-premolar region.
What is the growth potential of ossifying fibroma?
Potential for massive growth.
What is Langerhans Cell Histiocytosis?
Neoplastic proliferation of Langerhans cells.
What genetic mutation is associated with Langerhans Cell Histiocytosis?
BRAF mutation in 40-60%.
What are the types of Langerhans Cell Histiocytosis?
Acute/chronic disseminated histiocytosis, monostotic/polyostotic eosinophilic granuloma of bone.
Who is typically affected by Langerhans Cell Histiocytosis?
Young patients.
What oral manifestations are associated with Langerhans Cell Histiocytosis?
Proliferative gingival mass.
What radiographic appearance is associated with Langerhans Cell Histiocytosis?
“Floating in air” appearance.
What condition does Langerhans Cell Histiocytosis mimic?
Chronic periodontitis.
What is the treatment for Langerhans Cell Histiocytosis?
Curettage.
The most common primary malignant tumor of bone.
Osteosarcoma
What is the main characteristic of osteosarcoma?
Malignancy with the ability to produce osteoid or bone.
Age is typically affected by osteosarcoma?
Adolescents or those above age 60.
What radiographic features are associated with osteosarcoma?
Widening of PDL, spiking root resorption, Sunburst/Sunray appearance.
What is the most common malignancy affecting bone?
Metastatic carcinoma.
What are the most common primary sites for malignancies that metastasize to the jaw?
Breast (in females), lung, thyroid, prostate (in males), kidney, colorectal, melanoma.
What bones are most frequently affected by metastasis?
Vertebrae, ribs, pelvis, skull.
How does metastasis spread to the jaw?
Hematogenous spread via the Batson paravertebral plexus of veins.
What is the significance of jaw metastasis?
In 20-25% of cases, the metastatic deposit is the first indication of malignancy.
What radiographic appearance is associated with metastasis to the jaw?
Moth-eaten radiolucency.
What are bone characteristics of osteogenesis imperfecta?
Low bone density and bone fragility.
What is the genetic basis of osteogenesis imperfecta?
Autosomal dominant mutation of COL1A1 and COL1A2 affecting type 1 collagen formation.
What does type 1 collagen affect?
Bone, dentin, sclerae, ligaments, skin.
What are the dental alterations seen in osteogenesis imperfecta?
Dental alterations identical to dentinogenesis imperfecta, translucent teeth, shell teeth (Types 3 and 4).
What is osteopetrosis?
Increased bone density.
What is the underlying defect in osteopetrosis?
Defect in osteoclastic function/differentiation.
What are the types of osteopetrosis?
Autosomal recessive infantile, autosomal recessive intermediate, autosomal dominant adult.
What are the characteristics of autosomal recessive infantile osteopetrosis?
At birth or early infancy, normocytic anemia, bone marrow failure.
What are the characteristics of autosomal recessive intermediate osteopetrosis?
Later childhood onset, rare bone marrow failure.
What are the characteristics of autosomal dominant adult osteopetrosis?
Adolescence/adulthood onset, mildest form and most common, no anemia or bone marrow failure, increased density of jaw bones = susceptible to infection and fracture.
What does cleidocranial dysplasia affect?
Bone and teeth formation.
What gene is associated with cleidocranial dysplasia?
RUNX2 gene.
What skeletal features are affected in cleidocranial dysplasia?
Clavicles and skull (hypoplastic, discontinuous, or absent).
What oral features are associated with cleidocranial dysplasia?
Narrow, high arch palate, increased incidence of cleft palate, mandibular prognathism, failed eruption of permanent teeth, over-retention of primary teeth, supernumerary teeth.
