Developmental Disorders of the Bone Osteogenesis Imperfecta Brittle

Developmental Disorders of the Bone

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.

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

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

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

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

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

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

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

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

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

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

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

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