Bone Pathology

Question 1

briefly discuss the make up of compact bone

Answer 1

building units = osteons (rings of concentric lamellae)
in the centre of osteons is central (haversian) canals which contain blood vessels
central canals communicate via volkmans canals
osteocytes are housing in lacunae between lamellae - communicate vie canaliculi

Question 2

name 2 hormones that influence bone remodelling

Answer 2

parathyroid hormone
oestrogen

Question 3

what does parathyroid hormone do

Answer 3

released in response to low serum calcium
stimulates osteoclasts to resorb bone and release calcium stores

Question 4

influence of oestrogen on osteoclasts

Answer 4

oestrogen inhibits osteoclast activity

(post menopause = decreased oestrogen = osteoporosis)

Question 5

name 3 factors influencing bone remodelling

Answer 5

• cytokines
• systemic hormones
• mechanical stimuli

Question 6

name 3 developmental abnormalities of bone seen in the mouth

Answer 6

torus
osteopetrosis
fibrous dysplasia

(osteogenesis imperfecta, achondroplasia)

Question 7

osteopetrosis

Answer 7

developmental bone pathology
lack of osteoclast activity - can lead to marrow obliteration

Question 8

fibrous dysplasia

Answer 8

uncommon developmental bone pathology
slow growing asymptomatic bony swelling that stops after active growth period
can by monostotic (one bone) or polyostotic
fibrous replacement of bone
bone initially maintains initial shape

Question 9

name 3 inflammatory reactions of bone

Answer 9

• rareifying osteitis
• sclerosing osteitis (condensing)
• alveolar osteitis

(alveoalr osteitis, osteomyelitis)

Question 10

rareifying osteitis

Answer 10

localised loss of bone in response to inflammation
always occurs secondary to another form of pathology - apical periodontitis, periapical granuloma, periapical abscess

Question 11

sclerosing osteitis

Answer 11

localised increase in bone density in response to low grade inflammation
most common around apex of tooth with a necrotic pulp
needs treatment - risk of external root resorption or progression to abscess

(also called condensing osteitis)

Question 12

idiopathic osteosclerosis

Answer 12

localised increase in bone density of unknown cause
most common in premolar region of mandible, tend to be no larger than 1-2cm
no treatment required

Question 13

idiopathic vs sclerosing osteitis

Answer 13

can appear very similar if associated with a root
carry out sensibility testing of associated tooth
vital - likely idiopathic
non-vital - sclerosing osteitis

Question 14

osteomyelitis

Answer 14

rare, endogenous infection causing inflammation of the bone marrow
moth eaten appearance on radiographs

Question 15

3 main reasons for bone necrosis

Answer 15

osteomyelitis
avascular necrosis (age related ischaemia, anti-resorptive meds)
irradiation (ORN)

Question 16

name 3 metabolic bone diseases

Answer 16

osteoporosis
hyperparathyroidism
rickets/ osteomalacia

Question 17

osteoporosis

Answer 17

bone atrophy as bone resorption exceeds formation (quantitative deficiency)

Question 18

rickets and osteomalacia

Answer 18

rickets (children), osteomalacia (adults)
caused by vitamin D deficiency
osteoid forms but fails to canlcify resulting in weak bones

Question 19

function of vitamin D in the body

Answer 19

helps body absorb calcium