1. Developmental Disorders of the Bone

2. Osteogenesis Imperfecta (Brittle bone Syndrome)
It is hereditary disease of bone
Osteoporosis and Osteopetrosis
In osteporosis
Bones are fragile and brittle
It is often fatal if it develops during intraurterine life.
It may also develop during child hood or early adult life.

3. Osteogenesis Imperfecta (Brittle bone Syndrome)
In osteoporosis the long bones are thin with narrow poorly formed cortics
Fractures are common but usually heal without any trouble
The skull is thin and tends to bulge over the ear
The jaws are severely affected

4. Osteogenesis Imperfecta (Brittle bone Syndrome)
They consists of small delicate trabeculae
Cortices of the bone composed of immature woven bone Osteoblasts fail to form bone in adequate amount
Other abnormalities are joint hypermobility
Lax ligaments thin translucent skin, blue sclerae

5. Osteogenesis Imperfecta (Brittle bone Syndrome)
The basic defect appears to lie in collagenous matrix of the bone
It is suggested that the disturbance of normal cross-linking between collagen molecules as collagen matures
It is inherited as an autosomal dominont
It is often associated with dentinogenesis imperfecta

6. Osteopetrosis (Albers – Schoenberg or Marble Bone Disease)
It is characterized by excessive density of bones
Obliteration of marrow cavities
Development of secondary anemia
Defect in Osteoclastic activity
Failure in remodeling of developing bone

7. Osteopetrosis (Albers – Schoenberg or Marble Bone Disease)
There is an excessive bone formation which is mechanically weak so the fractures are common
Delayed eruption of teeth
Osteomyelitis is common complication of tooth extraction

8. Osteopetrosis (Albers – Schoenberg or Marble Bone Disease)
There are two types:
Malignant and prograsive inherited as autosomal recssive and occur early in life with severe bone fragility
Death usually occurs before buberty

9. Osteopetrosis (Albers – Schoenberg or Marble Bone Disease)
A benign autosomal dominant type
Bone charges are less severe
There may be repeated fracture following minor trauma

10. Osteopetrosis (Albers – Schoenberg or Marble Bone Disease)
RADIOLOGY shows increase density of bone in all skeleton with no distinction between cartical and madullary bone
Base of the skull shows marked radiopacity where as the vault is generally less dense

11. Osteopetrosis (Albers – Schoenberg or Marble Bone Disease)
RADIOLOGY
Mandible is more frequently affect than maxilla
Density of the bone reaches to the roots of the teeth so roots are invisible on X-Ray

12. Cleidocranial Dysostosis (Cleidocranial Dysplasia)
The disease is transmitted as an autosomal dominant trait
It is characterized by abnormalities of many bones
The disease is particularly of the skull, Jaws Clavicle and dental abnormalities

13. Cleidocranial Dysostosis (Cleidocranial Dysplasia)
In the skull the fontanelles and sutures tends to remain open
Skull appears flat with prominent frontal paratal and occipital bones
Partial or complete absence of clavicles allows the shoulders to be brought forwards until they meet in midline

14. Cleidocranial Dysostosis (Cleidocranial Dysplasia)
The maxilla may be under developed with high narrow arched palate
Deciduous dentition tends to retain with delayed or non eruption of permanent dentition
Multiple impactions and supernumerary teeth are common specially in a mandibular premolar and incisor region
The roots of teeth are thinner than normal