Bone Pathology

Question 1

What are the main regulators of bone remodelling?

Answer 1

Mechanical stimuli

Hormones:
- Parathyroid hormone
- Vit D3
- Oestrogen

Cytokines
- Perio
- Inflammatory diseases
- Pathological processes

Question 2

What special tests can be done to investigate bone pathology?

Answer 2

Serum calcium

Serum alkaline phosphatase (Osteoblastic activity)

Collagen in urine and blood (osteoclastic activity)

Parathyroid hormone levels

Vit D assays

Question 3

What are the main types of developmental bone defect?

Answer 3

Tori
Osteogenisis imperfecta
Achondroplasia
Osteoporosis
Fiberous dysplasia

Question 4

What is osteogenesis imperfecta?

Answer 4

Type 1 collagen defect

Inherited variance

Clinical features - weak bones, multiple fractures, sometimes associated with dentiogenisis imperfecta

Question 5

What is achondroplasia?

Answer 5

Autosomal dominant abnormality, causing poor endochondral ossification (dwarfism)

Question 6

What is osteopetrosis?

Answer 6

Lack of osteoclastic activity, failure of resorption, marrow obliteration.

Question 7

What is fiberous dysplasia?

Answer 7

Gene defect

Slow growing asymptomatic bony swelling (bone is replaced by fiberous soft tissue)

Stops growing after active growth period

Question 8

What is rarefying osteitis?

Answer 8

Localised loss of bone in response to inflammation

Always secondary to other pathology.

Question 9

What is sclerosing osteitis?

Answer 9

Localised increase in bone density in response to low grade inflammation.

Most common around apex of tooth, poorly defined, and may lead to ERR if chronic.

Question 10

What is idiopathic osteosclerosis?

Answer 10

A localised increase in bone density of unknown cause. Little effect on tooth structures.

Question 11

How do you determine whether its idiopathic osteosclerosis or sclerosing osteitis?

Answer 11

Sensibility testing. Sclerosing will occur in response to pulpal necrosis.

Question 12

What is osteomyelitis?

Answer 12

A rare endogenous infection, which can be acute or chronic.

Suppuration is rare, but can result in sequestrum, actinomycosis, or other complications.

Question 13

Describe the aetiology of bone necrosis.

Answer 13

Osteomyelitis (acute or chronic)

Avascular necrosis (age related ischaemia or medication related)

Irradiation (ORN)

Question 14

What are anti-resorbative medications used for?

Answer 14

Osteoporosis
Paget’s
Bone metastases

Question 15

Describe the aetiology of osteoporosis?

Answer 15

Sex hormone imbalance

Age

Calcium status/physical activity

Secondary to:
- Hyperparathyroidism
- Cushing’s
- Thyrotoxicosis
- Diabetes mellitus

Question 16

Whta is osteoporosis?

Answer 16

Bone atrophy, resorption > formation.

Symptomless, but weak bone and an enlarged antrum.

Question 17

What is Rickets/osteomalacia?

Answer 17

Vit D deficiency

Osteoid forms but fails to calcify

Poor endochondral bone

Question 18

What is hypoparathyroidism?

Answer 18

Calcium mobilised from bones, causing osteoporosis.

Primary associated with parathyroid adenoma.

Hypercalcaemia and increased bone turnover.

Question 19

What are the two types of giant cell lesion?

Answer 19

Peripheral (soft tissue)
Central (bone related)

Question 20

What is cherubism?

Answer 20

Rare autosomal dominant disorder

Multicystic/locular lesions in multiple quadrants

Regress after puberty.

Question 21

What is Paget’s syndrome?

Answer 21

Bone swelling, pain, nerve compression - unknown aetiology

Question 22

Give three exampled of bone tumours?

Answer 22

Osteoma (slow growing, cortical)

Osteoblastoma (rapid, osteoid)

Osteosarcoma (destruction of local tissues)