Bone Pathology I - Osteoporois, osteopetrosis, x-linked hyphophosphoataemia, cleidocranial dysplasia Flashcards
Inherited and developmental disorders of bone?
- Osteogenesis imperfecta
- Osteopetrosis (marble bone disease)
- Achondroplasia
- Cleidocranial dysplasia (cleidocranial dysostosis)
- X-linked hypophosphatemia
- Fibro-osseous lesions
- Cherubism
- Noonan’s Syndrome
Mutataion in osteogenesis imperfects?
Genes that code for collagen I
Osteogenesis imperfecta?
- Generalised osteoporosis.
- Slender long bones with narrow poorly formed cortices.
- Immature woven bone.
- Fracture tendency, healing may form exuberant callus.
What is osteogenesis imperfecta associated with?
Dentinogenesis imperfecta
Effect of osteogenesis imperfecta on the eye?
- The sclerae are thin and the pigmented choroid shines
through. Therefore, the sclerae appear blue.
Effect of osteogenesis imperfecta on teh eyes, skin, ear and heart?
- Thin translucent skin.
- Joint hypermobility with lax ligaments.
- Deafness is common due to the distortion of the ossicles in
the ear. - Heart valve defects.
Osteopertrosis aka?
- Marble bone disease, Albers- Schonberg disease.
Osteopetrosis?
- 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.
What bone disease?
Osteopetrosis
Radiographic presentation of osteopetrosis?
- 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.
Achondroplasia?
- 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.
Cleidocranial dysplasia affects what bones?
- Skull: open fontanelles,
prominent frontal, parietal and
occipital bones. - Depressed nasal bridge.
- Dental anomalies.
- Partial or complete absence
of clavicles.
Bone disease?
Cleidocranial Dysplasia
Radiographic appearance of Cleidocranial Dysplasia?
- 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
X- linked Hypophosphataemia?
- 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.
significance of collage type I?
bone
PDL
cementum
skin
tendons and ligaments.
dentinogenesis imperfecta?
Dentinogenesis imperfecta is characterized by abnormal dentin leading to the appearance of small deformed teeth
often weak teeth
blue/grey in colour
Osteopetrosis effects what cell?
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
pt with osteopetrosis, what occurs after extraction?
osteomyelitis
what systemc disease can osteopetrosis cause?
secondary anaemia
due to no haemoatopaosis form bine marrow
why is bone prone to infection when you extract teeth in osteopetrosis?
the marrow is destroyed - no vascularity
bone is prone to infection
how does the bone appear in osteopetrosis?
like marble
no distinction between trabecular and cortical bone
all the same density
what happens f the maxilla is affected by osteopetrosis?
complete obliteration of maxillary sinus
breakdown the word achondroplasia?
chondro = cartilage
abnormal endochondral ossification
- cartilage doesn’t ossify
long bones don’t grow
what bones disease common reason for dwarfism
achondroplasia
clinical features of achondroplasia?
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
what disease affects cellular cementum?
cleidocranial dysplasia
how does cleidocranial dysplasia affect cellular cementum?
sparse of even missing cellular cementum
thin roots on radiographs
Why do cleidocranial dysplasia pts retain their primary teeth for longer?
failure of eruption of permanent teeth
What cysts are associated with cleidocranial dysplasia?
dentigerous cysts
- because of the impacted teeth
vitamin D resistant bone disease?
x-linked hypophosphataemia
a type of rickets
Can you treat x-linked hypophosphataemia?
no - pt resistant to vit D
What is X-linked hypophosphataemia characterised by?
low serum phosphate levels and a lack of response to tx with vt D
in contract to nutritional rickets
clinical presentation of X-linked hypophosphataemia?
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
