BDS4 bone pathology

Question 1

what is systemic hormones of bone remodelling?

Answer 1

• Parathyroid hormone (PTH)
• Vitamin D3
• Oestrogen
• others

Question 2

what is special tests of bone biochemistry?

Answer 2

• Blood calcium
• Osteoblast activity (bone formation)
  *Serum alkaline phosphatase
  *Osteocalcin
• Osteoclast activity (bone resorption)
  *Collagen degradation urine & blood
• Parathyroid hormone
• Vitamin D assays (>50 nmol/L adequate)

Question 3

what is types of torus?

Answer 3

Torus
* Developmental
* Exostosis

Problem with fitting dentures

Types
* Torus palatinus
*Midline of palate
* Torus/tori mandibularis
*Bilateral on lingual aspect of mandible (usually premolar region)

Question 4

what is this?

Answer 4

Torus mandibularis

Question 5

what are types of developmental abnormality conditions

Answer 5

Osteogenesis imperfecta
Achondroplasia
Osteopetrosis
Fibrous dysplasia

Question 6

what are characteristics and clinical features of osteogenesis imperfecta?

Answer 6

• Type 1 collagen defect
• Inheritance varied – 4 main types
• Clinical features
  *Weak bones, multiple fractures
  *Sometimes associated with dentinogenesis imperfecta

Question 7

what is characteristics of achondroplasia?

Answer 7

• Autosomal dominant
• Poor endochondral ossification
• Dwarfism

Question 8

what is characteristics of osteopetrosis

Answer 8

• Lack of osteoclast activity
• Failure of resorption
• Marrow obliteration

Question 9

what are characteristics of fibrous dysplasia?

Answer 9

Uncommon
* Gene defect
Slow growing, asymptomatic bony swelling
* Bone replaced by fibrous tissue
Active under 20 years
Stops growing after active growth period (usually…)
Serum biochemistry norma

Question 10

what are clinical phenotypes of fibrous dysplasia?

Answer 10

• Determined by timing of gene mutation
• Monostotic: single bone
  *More common
  *Maxilla > mandible
  *Facial asymmetry
• Polyostotic: many bones
• May be syndromic – Albright’s syndrome
  *Melanin pigment
  *Early puberty

Question 11

what does fibrous dysplasia look like radiographically?

Answer 11

• Variable appearances
• Margins often blend into adjacent bone
• Bone maintains approximate shape (initially)
• Becomes more radiopaque as lesion matures

Question 12

what is histology of active fibrous dysplasia?

Answer 12

Fibrous replacement of bone
* Cellular fibrous tissue
* Bone – metaplastic or woven, but
will remodel & increase in density

Question 13

what is rarefying osteitis?

Answer 13

Localised loss of bone in response to inflammation
* Always occurring secondary to another form of pathology
* If at apex of tooth consider apical periodontitis, periapical granuloma or periapical abscess

Question 14

what is sclerosis osteitis?

Answer 14

• Localised increase in bone density in response to low-grade inflammation
• Most common around apex of tooth with a necrotic pulp
  *Periapical radiopacity, often poorly-defined
  *May eventually lead to external root resorption if chronic

Question 15

what is idiopathic osteosclerosis?

Answer 15

Localised increase in bone density of unknown cause
* a.k.a. dense bone island
* Most common in premolar-molar region of mandible
* Always asymptomatic
* No bony expansion & no effect on adjacent teeth/structures

Question 16

how to tell difference between idiopathic osteosclerosis and sclerosing osteitis

Answer 16

Carry out sensibility testing on the tooth involved

Question 17

what is aetiology of bone necrosis?

Answer 17

• Osteomyelitis
  *Acute or chronic
• Avascular necrosis
  *Age-related ischaemia
  *Anti-resorptive medication
• Irradiation
  *Osteoradionecrosis
  **Prone to infections

Question 18

what are osteoclast inhibitors used for?

Answer 18

• osteoporosis
• Paget’s
• bone metastases

Question 19

what are types of metabolic bone disease?

Answer 19

• Osteoporosis
• Rickets & Osteomalacia
• Hyperparathyroidism

Question 20

what is osteoporosis and clinical and radiographic features?

Answer 20

• Bone atrophy: resorption exceeds formation
  *Endosteal net bone loss
  *Quantitative deficiency (bone formed is normal)
• Clinical features
  *Symptomless
  *Weak bone
  *Antrum enlarged
• Radiographic features
  *Loss of normal bone markings

Question 21

what is aetiology of osteoporosis?

Answer 21

• Sex hormone status
• Age
• Calcium status & physical activity
• Secondary osteoporosis
  *Hyperparathyroidism
  *Cushing’s syndrome
  *Thyrotoxicosis
  *Diabetes mellitus
  others

Question 22

what is characteristics of rickets and ostemalacia?

Answer 22

• Vitamin D deficiency
  *Lack of sunlight – daylight hours
  *Diet
  *Malabsorption
  *Renal causes
• Osteoid forms but fails to calcify
• Rickets
  *Poor endochondral bone
  *Low calcium
  *Raised alkaline phosphatase

Question 23

what is hyperparathyroidism and types?

Answer 23

• Calcium mobilised from bones
  *Generalised osteoporosis
  *Osteitis fibrosa cystica (“brown tumours”)
  *Metastatic calcification – kidney
• Types
  *Primary: neoplasia / hyperplasia
  *Secondary: hypocalcaemia (e.g. due to vitamin D deficiency)
  *Tertiary: hyperplasia as a result of prolonged secondary

Question 24

what is increased primary hyperparathyroidism?

Answer 24

• mainly posmenopausal women
• 90% parathyroid adenoma (→ increased parathyroid hormone)
  *Hypercalcaemia
  *Increased bone turnover

Question 25

what is giant cell lesions of the jaws?

Answer 25

• Peripheral giant cell epulis
• Central giant cell granuloma
  *Age 10-25
  *Mandible>maxilla
  *May be multilocular
• Differential diagnosis
  *Osteitis fibrosa cystica
  *Aneurysmal bone cyst
  *Giant cell tumours (very rare)
• Central lesions may “burst out”

Question 26

what is cherubism? histology

Answer 26

• Rare condition
• Autosomal dominant inheritance
• Multicystic/multilocular lesions in multiple quadrants
• Grow before about 7 years & regress after puberty
• Histology: vascular giant cell lesions

Question 27

what is paget’s disease of bone?

Answer 27

Age > 40, M>F
3% of routine autopsies
Aetiology unknown
* Racial predilection
* Viral?
Monostotic or polyostotic
Serum biochemistry
* Raised alk phos
Clinical
* bone swelling, pain, nerve compression

Question 28

what is bone patterns and dental changes of paget’s disease of bone?

Answer 28

Variable bone pattern
* Changes as disease progresses
* Osteoporotic / mixed / osteosclerotic
Dental changes
* Loss of lamina dura
* Hypercementosis
* Migration (due to bone enlargement)

Question 29

what is histology and complications of paget’s bone disease?

Answer 29

Histology
* Active: increased bone turnover
* Osteoclastic & osteoblastic activity
* Will burn out
Complications
* Infection
* Tumour

Question 30

what are types of bone tymours?

Answer 30

• Osteoma
  *Solitary
  *Mostly cortical bone
  *Slow growing
  *If multiple osteomas:
  **Consider Gardner syndrome
• Osteoblastoma
  *Rare
  *May be a Giant Osteoid Osteoma
  *Often very active growth

Question 31

what is clinical and histological features of ossifying fibroma?

Answer 31

• Clinical
  *Slow growing
  *Wide age range
  *Mainly mandible
  *Radiologically well-defined
• Histology
  *Cellular fibrous tissue
  *Immature bone
  *Acellular calcifications

Question 32

what are types of cementum lesions?

Answer 32

Cementoblastoma
*Neoplasm attached to root
*Histology same as osteoblastoma
Cemento-osseous dysplasias
*Nomenclature problem, probably not neoplastic
*Types:
**Periapical COD
**Focal COD
**Florid COD
*Starts as radiolucency → later calcification

Question 33

what is osteosarcoma charcateritics?

Answer 33

Age 30’s
*If elderly, likely Paget’s-related

Characteristics
* Mandible > maxilla
* Varied clinical & x-ray presentation
* Local destruction
* Recurrence & metastasis

Question 34

Answer 34

cementoblastoma