Bone Pathology I - Osteoporois, osteopetrosis, x-linked hyphophosphoataemia, cleidocranial dysplasia

Question 1

Inherited and developmental disorders of bone?

Answer 1

• Osteogenesis imperfecta
• Osteopetrosis (marble bone disease)
• Achondroplasia
• Cleidocranial dysplasia (cleidocranial dysostosis)
• X-linked hypophosphatemia
• Fibro-osseous lesions
• Cherubism
• Noonan’s Syndrome

Question 2

Mutataion in osteogenesis imperfects?

Answer 2

Genes that code for collagen I

Question 3

Osteogenesis imperfecta?

Answer 3

• Generalised osteoporosis.
• Slender long bones with narrow poorly formed cortices.
• Immature woven bone.
• Fracture tendency, healing may form exuberant callus.

Question 4

What is osteogenesis imperfecta associated with?

Answer 4

Dentinogenesis imperfecta

Question 5

Effect of osteogenesis imperfecta on the eye?

Answer 5

• The sclerae are thin and the pigmented choroid shines
  through. Therefore, the sclerae appear blue.

Question 6

Effect of osteogenesis imperfecta on teh eyes, skin, ear and heart?

Answer 6

• Thin translucent skin.
• Joint hypermobility with lax ligaments.
• Deafness is common due to the distortion of the ossicles in
  the ear.
• Heart valve defects.

Question 7

Osteopertrosis aka?

Answer 7

• Marble bone disease, Albers- Schonberg disease.

Question 8

Osteopetrosis?

Answer 8

• Defect in the differentiation and function of osteoclasts.
• Abnormal formation of the skeleton and increased bone
  mass.
• Dense fragile bones prone to infection and fractures.
• Obliteration of marrow spaces,
  secondary anaemia.
• Delayed tooth eruption.
• Osteomyelitis following extractions.

Question 9

What bone disease?

Answer 9

Osteopetrosis

Question 10

Radiographic presentation of osteopetrosis?

Answer 10

• Radiographically, no distinction between cortical and trabecular bone.
• Variation in Jaw involvement.
• Mandible more frequently affected.
• Roots may be invisible in radiographs due to bone density being so high
• Possible obliteration of the maxillary sinus.

Question 11

Achondroplasia?

Answer 11

• Most common form of dwarfism.
• Abnormal endochondral ossification.
• Defect or absence in the zone of provisional calcification of the cartilage in the epiphyses and base of the skull.
• Retrusive facial middle third
  due to defective growth of the
  base of the skull.
• Severe malocclusion.

Question 12

Cleidocranial dysplasia affects what bones?

Answer 12

• Skull: open fontanelles,
  prominent frontal, parietal and
  occipital bones.
• Depressed nasal bridge.
• Dental anomalies.
• Partial or complete absence
  of clavicles.

Question 13

Bone disease?

Answer 13

Cleidocranial Dysplasia

Question 14

Radiographic appearance of Cleidocranial Dysplasia?

Answer 14

• Underdeveloped maxilla with a high narrow arched palate.
• Sparse or even missing cellular cementum.
• Retained deciduous dentition.
• Multiple impactions.
• Supernumerary teeth.
• Dentigerous cysts.
• Thin roots.
• thin roots

Question 15

X- linked Hypophosphataemia?

Answer 15

• Vitamin D resistant rickets.
• A type of rickets characterized by low serum phosphate
  levels and a lack of response to treatment with vitamin D, in
  contrast to nutritional rickets.
• Short stature, and radiographs show short and squat long
  bones.
• Delayed eruption of teeth.
• Dentine fails to mineralise properly and the pulp may
  become infected through pulp horn defects, leading to
  abscess formation in the absence of dental caries.
• Predentine is widened, whilst circumpulpal dentine is
  thinned and resembles interglobular dentine.

Question 16

significance of collage type I?

Answer 16

bone
PDL
cementum
skin
tendons and ligaments.

Question 17

dentinogenesis imperfecta?

Answer 17

Dentinogenesis imperfecta is characterized by abnormal dentin leading to the appearance of small deformed teeth

often weak teeth

blue/grey in colour

Question 18

Osteopetrosis effects what cell?

Answer 18

osteoclasts are defective

bone resorption doe not take place - constant been deposition

bone density increased

fragile bone

no resilience from trabecular bone and bone marrow spaces are obliterated

Question 19

pt with osteopetrosis, what occurs after extraction?

Answer 19

osteomyelitis

Question 20

what systemc disease can osteopetrosis cause?

Answer 20

secondary anaemia

due to no haemoatopaosis form bine marrow

Question 21

why is bone prone to infection when you extract teeth in osteopetrosis?

Answer 21

the marrow is destroyed - no vascularity

bone is prone to infection

Question 22

how does the bone appear in osteopetrosis?

Answer 22

like marble

no distinction between trabecular and cortical bone

all the same density

Question 23

what happens f the maxilla is affected by osteopetrosis?

Answer 23

complete obliteration of maxillary sinus

Question 24

breakdown the word achondroplasia?

Answer 24

chondro = cartilage

abnormal endochondral ossification

• cartilage doesn’t ossify

long bones don’t grow

Question 25

what bones disease common reason for dwarfism

Answer 25

achondroplasia

Question 26

clinical features of achondroplasia?

Answer 26

normal size of head and trunk limbs excessively short retrusive facial middle third due to defective growth pf the base of the skull severe malocclusion

Question 27

what disease affects cellular cementum?

Answer 27

cleidocranial dysplasia

Question 28

how does cleidocranial dysplasia affect cellular cementum?

Answer 28

sparse of even missing cellular cementum thin roots on radiographs

Question 29

Why do cleidocranial dysplasia pts retain their primary teeth for longer?

Answer 29

failure of eruption of permanent teeth

Question 30

What cysts are associated with cleidocranial dysplasia?

Answer 30

dentigerous cysts - because of the impacted teeth

Question 31

vitamin D resistant bone disease?

Answer 31

x-linked hypophosphataemia a type of rickets

Question 32

Can you treat x-linked hypophosphataemia?

Answer 32

no - pt resistant to vit D

Question 33

What is X-linked hypophosphataemia characterised by?

Answer 33

low serum phosphate levels and a lack of response to tx with vt D in contract to nutritional rickets

Question 34

clinical presentation of X-linked hypophosphataemia?

Answer 34

short stature and radiographs show short and squat long bones delayed eruption of teeth dentine fails to mineralise properly and the pulp may become infected through pulp horn defects leading to abscess formation in the absence of dental caries predentine is widened, whilst circumpulpal dentine is thinned and resembles interglobular dentine phosphoryn important in dentine mineralisation