Bone Lesions

Question 1

What are the three main types of bone?

Answer 1

Lamellar bone, Non-lamellar (woven) bone, and Bundle bone.

Question 2

What cells are responsible for bone remodeling?

Answer 2

Osteoclasts (destruction) and Osteoblasts (formation).

Question 3

What is woven bone?

Answer 3

Embryonic, coarse-fibered bone seen in fetal life, fracture sites, and extraction sockets.

Question 4

Normal serum calcium level?

Answer 4

9–11 mg/dl.

Question 5

Normal serum phosphorus level?

Answer 5

2.5–4.5 mg/dl.

Question 6

Normal alkaline phosphatase level?

Answer 6

30–130 IU/l.

Question 7

What are fibro-osseous lesions?

Answer 7

Lesions where normal bone is replaced by fibrous tissue that forms immature calcified tissue.

Question 8

Define metaplasia.

Answer 8

Reversible transformation of one differentiated tissue type into another of the same category.

Question 9

Is fibrous dysplasia inherited?

Answer 9

No, it is developmental but not inherited.

Question 10

Most common type of fibrous dysplasia?

Answer 10

Monostotic type (80–85% of cases).

Question 11

Common jaw site for fibrous dysplasia?

Answer 11

Maxilla more than mandible.

Question 12

In which decade is fibrous dysplasia commonly diagnosed?

Answer 12

First or second decade of life.

Question 13

Which sex is more affected by polyostotic fibrous dysplasia?

Answer 13

Females (2–3 times more than males).

Question 14

What is Jaffe’s syndrome?

Answer 14

Polyostotic fibrous dysplasia + café-au-lait spots with mostly normal skeleton.

Question 15

What is Albright’s syndrome?

Answer 15

Polyostotic fibrous dysplasia + café-au-lait spots + endocrinal disorders.

Question 16

Jaw symptoms of fibrous dysplasia?

Answer 16

Facial asymmetry, tooth displacement, failure of eruption.

Question 17

Radiographic early stage of fibrous dysplasia?

Answer 17

Cyst-like radiolucency.

Question 18

Radiographic mixed stage of fibrous dysplasia?

Answer 18

Coarse mottling – “smoke screen” pattern.

Question 19

Final radiographic stage of fibrous dysplasia?

Answer 19

Ill-defined radiopaque areas; displaced roots.

Question 20

Characteristic histopathology of fibrous dysplasia?

Answer 20

Fibrous tissue with irregular immature woven bone in Chinese script pattern.

Question 21

Most common site for ossifying fibroma?

Answer 21

Mandibular tooth-bearing areas.

Question 22

Clinical features of ossifying fibroma?

Answer 22

Painless hard swelling, slow growth, tooth displacement.

Question 23

Radiographic feature of ossifying fibroma?

Answer 23

Well-circumscribed lesion with variable calcification.

Question 24

Histopathology of ossifying fibroma includes what calcifications?

Answer 24

Woven bone, lamellar bone, cementum-like material.

Question 25

What characterizes giant cell lesions?

Answer 25

Presence of multinucleated giant cells (MNGCs).

Question 26

Origin of MNGCs?

Answer 26

Monocytic/macrophage or osteoclastic origin.

Question 27

Is CGCG considered a reactive or neoplastic lesion?

Answer 27

Benign neoplasm due to occasional aggressive behavior.

Question 28

CGCG common age group?

Answer 28

Children and young adults (<30 years).

Question 29

CGCG common site?

Answer 29

Anterior mandible > maxilla.

Question 30

Histology of CGCG?

Answer 30

MNGCs in vascular stroma with hemorrhage, RBCs, hemosiderin.

Question 31

What is peripheral giant cell granuloma (PGCG)?

Answer 31

Reactive hyperplasia of gingival tissue, not a true neoplasm.

Question 32

PGCG common site?

Answer 32

Gingiva or alveolar mucosa anterior to molars.

Question 33

Clinical appearance of PGCG?

Answer 33

Red-blue painless swelling, often pedunculated or sessile.

Question 34

Radiographic feature of PGCG?

Answer 34

Superficial bone erosion; cup-shaped radiolucency on edentulous ridge.

Question 35

PGCG histological hallmark?

Answer 35

Focal MNGCs, vascular stroma, hemosiderin, and chronic inflammation.

Question 36

What causes brown tumor?

Answer 36

Hyperparathyroidism.

Question 37

Classic oral findings in brown tumor?

Answer 37

Cystic radiolucency, osteoporosis, loss of lamina dura, pulp calcification.

Question 38

Brown tumor histopathology is identical to?

Answer 38

Central giant cell granuloma.

Question 39

Brown tumor diagnostic tests?

Answer 39

Biochemical tests for hyperparathyroidism + clinical and radiographic features.

Question 40

What is cherubism?

Answer 40

Hereditary benign condition with jaw expansion, autosomal dominant.

Question 41

Age and sex predilection of cherubism?

Answer 41

2–5 years old; females > males.

Question 42

Facial appearance in cherubism?

Answer 42

Chubby cheeks, upward turned eyes – “cherubic” appearance.

Question 43

Dental findings in cherubism?

Answer 43

Early tooth loss, delayed eruption, malocclusion.

Question 44

Course of cherubism over time?

Answer 44

Rapid growth until age 7, then stabilizes and regresses.

Question 45

Radiographic pattern in cherubism?

Answer 45

Multilocular radiolucency with soap-bubble appearance.

Question 46

Histology of cherubism?

Answer 46

Giant cells in fibrous stroma, vascular channels, hyaline collagen cuff.

Question 47

What collagen pattern is pathognomonic for cherubism?

Answer 47

Hyaline, eosinophilic collagen cuff around blood vessels.

Question 48

In which jaw does cherubism occur more commonly?

Answer 48

Mandible > Maxilla.

Question 49

Are mature cherubism lesions aggressive?

Answer 49

No, they show more fibrous tissue, fewer giant cells, and bone formation.

Question 50

What gene is implicated in fibrous dysplasia?

Answer 50

GNAS1 gene.