Bone Pathology Flashcards
What systemic hormones are involved with bone remodelling?
Parathyroid hormone
Vitamin D3
Oestrogen
What is the role of PTH in bone remodelling?
Activates osteoclasts when there is a decrease in serum calcium
What is the role of osetrogen in bone remodelling?
When oestrogen levels are low (eg menopause), osteoclast receptors become unblocked which activates the osteoclast. This causes bone resorption.
What factors, other than hormones, affect bone remodelling?
Mechanical stimuli
Cytokines
What are torus?
A developmental abnormality
Growth of bone
In midline of palate = torus palatinus
In mandible (bilateral) = tori mandibularis
What is osteogenesis imperfecta?
Type 1 collagen defect
Resulting in weak bones, multiple fractures (+/- dentinogenesis imperfecta)
What is achondroplasia?
Autosomal dominant condition resulting in poor endochpndral ossification
(Dwarfism)
What is osteopetrosis?
Lack of osteoclast activity- failure of resorption
Marrow obliteration
What is fibrous dysplasia?
An uncommon gene defect associated with:
A slow growing, asymptomatic bony swelling (active under 20 years and stops growing after active growth period).
Serum biochemistry is normal.
Can be monostotic (single bone) or polystotic
Caused by fibrous replacement of bone
May be related to Albrights syndrome
What is rarefying osteitis?
Localised bone loss in response to inflammation
Always occurs secondary to another form of pathology (eg apical periodontitis)
What is sclerosing osteitis?
Localised increase in bone density in response to low grade inflammation
Most common at apex of tooth with necrotic pulp
What is idiopathic osteosclerosis?
Localised increase in bone density of unknown cause
(Bony island)
Most common in premolar region of mandible
No expansion.
If suspected - sensibility test nearby teeth to rule out sclerosing osteitis
What is alveolar osteitis?
Dry socket
Complication for extraction resulting in bone clot becoming dislodged
Severe pain - manage symptomatically.
What is Osteomyelitis?
A rare endogenous infection
Can be acute or chronic
(May be actinomycosis caused by actinomyces post extraction).
What are the aetiology’s of bone necrosis?
Osteomyelitis
A vascular necrosis (age related, anti resorptive)
Irradiation
What are 3 examples of metabolic bone disease?
Osteoporosis
Rickets and osteomalacia
Hyperparathyroidism
What is osteoporosis?
Bone atrophy (resorption exceeds formation)
- quantitative deficiency
Signs - symptomless, weak bones, antrum enlarged
Side effect of long term steroids
What are the aetiologies of osteoporosis?
Sex hormones
Age
Calcium status and physical activity
Secondary osteoporosis to hyperparathyroidism, Cushing’s syndrome, diabetes mellitus…
What is rickets/ osteomalacia?
A vitamin D deficiency (lack of sunlight, diet, malabsorption, renal causes).
Osteoid forms but fails to calcify.
What is hyperparathyroidism?
Calcium is mobilised from bones causing generalised osteoporosis, osteitis fibrosa cystica (brown tumours) and metastatic calcification.
Can be:
Primary - neoplasia/ hyperplasia
Secondary - hypocalcaemia
Tertiary - hyperplasia as a result of prolonged secondary
What is cherubism?
A rare condition with autosomal dominant inheritance
Resulting in multicystic/ multilocular lesions in multiple quadrants
Grows before 7 years and then regresses
- vascular giant cell lesions
What is pagers disease?
Chronic disease of bone which causes bone to grow large but weak.
Can be monostotic or polystotic
Raised alkaline phosphotase (2-3x higher)
Results in bone swelling, pain, nerve compression
What are the dental changes in Paget’s disease?
Loss of lamina dura
Hypercementosis
Migration (due to bone enlargement)
What are the complications of Paget’s disease?
Infection risk
Tumour risk - can develop osteosarcoma
What is an osteoma?
A solitary bone tumour (mostly cortical bone) - slow growing.
If multiple osteomas, consider Gardner syndrome (risk of polyps in colon)
What is osetoblastoma?
Rare giant osteoid osteoma
Very active growth
