Developmental Disorders of the Bone

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