Bone Pathology

Question 1

What is the building unit of compact bone?

Answer 1

Osteon (haversian system)

Question 2

Where are bone pain receptors and vessels located?

Answer 2

Periosteum

Question 3

On this image, what are the dark cells?

Answer 3

Osteoblasts

Question 4

What hormones are involved in bone remodelling?

Answer 4

• parathyroid hormone [activates osteoclasts when theres a decrease in serum calcium]
• vitamin D3
• oestrogen

Question 5

What factors are involved in bone remodelling?

Answer 5

• mechanical stimuli
• systemic hormones
• cytokines [eg via periodontal disease or infection]

Question 6

What special tests should you do if you suspect bone pathology?

Answer 6

Check
- blood calcium
- parathyroid hormone
- vitamin D
- serum alkaline phosphatase

Question 7

What tests can be done to check osteoclast activity?

Answer 7

Check collagen degradation in urine & blood

Question 8

What restorative problems are associated with tori?

Answer 8

Difficulty fitting dentures

Question 9

What are some types of tori?

Answer 9

• torus palatinus
• torus mandibularis

Question 10

What abnormality is seen in this photo?

Answer 10

Mandibular tori

Question 11

How can you manage mandibular tori that are interfering with denture fit?

Answer 11

Raise flap and drill them off

Question 12

What type of slice is seen on this CBCT?

Answer 12

Axial

Question 13

What is osteogenesis imperfecta? What are the clinical features?

Answer 13

Type 1 collagen defect
- weak bones
- multiple fractures
- sometimes associated with dentinogenesis imperfecta

Question 14

What is achondroplasia?

Answer 14

Condition that causes poor endochondral ossification
- leads to dwarfism

Question 15

What is osteopetrosis?

Answer 15

Condition with lack of osteoclast activity
- failure of resorption
- marrow obliteration
- leads to brittle, dense bone

Question 16

What causes fibrous dysplasia? What is it?

Answer 16

Gene defect that causes slow growing asymptomatic bony swelling (bone replaced by fibrous tissue)

Question 17

What are the clinical phenotypes of fibrous dysplasia?

Answer 17

• Monostotic = single bone
• Polyostotic = many bones

Question 18

What pathology is seen in this photo?

Answer 18

Fibrous dysplasia?

Question 19

What syndrome is associated with fibrous dysplasia?

Answer 19

Albright’s syndrome

Question 20

How does fibrous dysplasia present on radiographs?

Answer 20

• “ground glass” “orange peel”
• margins often blend into adjacent bone
• becomes more radiopaque as lesion matures

Question 21

What age are patients typically with fibrous dysplasia?

Answer 21

Teenagers and young adults

Question 22

What is the histopathological presentation of fibrous dysplasia?

Answer 22

• fibrous replacement of bone
• cellular fibrous tissue

Question 23

What is rarefying osteitis?

Answer 23

Localised loss of bone in response to inflammation
- always occurs secondary to another form of pathology (eg apical periodontitis)

Question 24

What is sclerosing osteitis?

Answer 24

Localised increase in bone density in response to low-grade inflammation
- most common around apex of tooth with a necrotic pulp?

Question 25

What can chronic sclerosing osteitis lead to?

Answer 25

External root resorption

Question 26

What is idiopathic osteosclerosis?

Answer 26

Localised increased in bone density of unknown cause

Question 27

Where is most common area to see idiopathic osteosclerosis?

Answer 27

premolar-molar region of mandible

Question 28

How can you tell if a patient has idiopathic osteosclerosis or sclerosing osteitis?

Answer 28

Carry out sensibility testing on tooth involved

Question 29

What is osteomyelitis?

Answer 29

Rare endogenous infection of the bone - can be acute or chronic

Question 30

How is actinomycosis treated?

Answer 30

Long term antibiotic treatment

Question 31

What is the aetiology of bone necrosis?

Answer 31

- Osteomyelitis - Avascular necrosis - Irradiation

Question 32

What can cause avascular necrosis of bone?

Answer 32

- age related ischaemia - anti-resorptive medication

Question 33

What cancers are anti-resorptive medications used for and why?

Answer 33

Cancers that metastasise to bone (eg breast cancer) - osteoclasts inhibit bone turnover which reduces amount of metastasis

Question 34

Give examples of metabolic bone diseases:

Answer 34

- osteoporosis - rickets & osteomalacia - hyperparathyroidism

Question 35

What is osteoporosis?

Answer 35

Bone atrophy: resorption exceeds formation - quantitative deficiency (bone formed is normal)

Question 36

What are the clinical features of osteoporosis?

Answer 36

- symptomless - weak bone / multiple fractures - antrum enlarged

Question 37

What is the aetiology of osteoporosis?

Answer 37

- sex hormone status - age [older>>] - calcium status & physical activity - secondary to other conditions

Question 38

What conditions can result in secondary osteoporosis?

Answer 38

- hyperparathyroidism - cushing's syndrome - thryotoxicosis - diabetes mellitus

Question 39

What is osteomalacia? What can cause it?

Answer 39

Osteoid forms but fails to calcify - vit D deficiency

Question 40

What can cause a vitamin D deficiency?

Answer 40

- lack of sunlight - diet - malabsorption - renal causes

Question 41

How does hyperparathyroidism cause osteoporosis?

Answer 41

- PTH stimulates osteoclasts - PTH mobilises calcium from bones

Question 42

What classifications of hyperparathyroidism exist?

Answer 42

Primary - neoplasia/hyperplasia Secondary - hypocalcaemia [due to vit D deficiency] Tertiary - hyperplasia as a result of secondary

Question 43

Who is most likely to suffer from primary hyperparathyroidism?

Answer 43

Postmenopausal women [F:M 3:1]

Question 44

How is Cherubism passed on?

Answer 44

Autosomal dominant inheritance

Question 45

What is cherubism?

Answer 45

Rare condition causing multicystic/multilocular lesions in multiple quadrants

Question 46

What are the clinical features of pagets disease?

Answer 46

- bone swelling - pain - nerve compression

Question 47

What are the dental presentations of paget's disease?

Answer 47

- loss of lamina dura - hypercementosis - migration of teeth (due to bone enlargement)

Question 48

How does Paget's disease present histologically?

Answer 48

- increased osteoclastic activity - increased osteoblastic activity

Question 49

Give examples of bone tumours:

Answer 49

- osteoma - osteoblastoma

Question 50

What is an osteoma?

Answer 50

Solitary bone tumour - mainly cortical bone - slow growing

Question 51

What syndrome can cause multiple osteomas?

Answer 51

Gardners syndrome

Question 52

How does ossifying fibroma present histologically?

Answer 52

- cellular fibrous tissue - immature bone - acellular calcifications

Question 53

What is a cementoblastoma?

Answer 53

Neoplasm attached to root - histologically the same as osteoblastoma

Question 54

What is seen in these radiographs?

Answer 54

Cementoblastoma