Group of rare disorders affecting the connective
tissue and characterized by extremely fragile bones that break or fracture
easily during the antenatal and postnatal periods (brittle bones). The
severity of osteogenesis imperfecta varies greatly, even among individuals
of the same family. Four main types have been identified. Type I is the most
common and the mildest form of the disorder. Type II is the most severe form.
Boy with scoliosis and short stature suffers from osteogenesis
imperfecta type III.
Head radiographs of a 6-month-old child with osteogenesis imperfecta
congenita show an enlarged skull with multiple wormian bones.
Multiple and bilateral rib fractures with healing callus formation can
be identified on the chest radiograph (same patient as in previous pictures).
Deformation and buckling fractures of the femora bilaterally (same
patient as in previous pictures).
Severe deformity of tibia and fibula with buckling fractures on both
sides in the same child with osteogenesis imperfecta congenita. Growth
retardation lines can be identified on the proximal diaphysis of tibia and
Brittle Bone Disease; Ekman-Lobstein Syndrome; Lobstein
Disease; Fragilitas Ossium.
There are four types of osteogenesis imperfecta.
Subdivision types A and IB are based on the absence or presence of
dentinogenesis imperfecta within each condition.
Type I (Osteogenesis Imperfecta Tarda; Osteogenesis Imperfecta with Blue Sclerae):
Dominantly inherited, generalized connective tissue disorder characterized
mainly by bone fragility and blue sclerae.
Type II (Osteogenesis Imperfecta Congenita; Neonatal Lethal Form Osteogenesis
Imperfecta; Vrolik Osteogenesis Imperfecta Syndrome): Autosomal dominant
characterized by spontaneous fractures, generalized osteoporosis, and
wormian bones in the area of the lambdoidal sutures. Blue sclerae and
deafness are not present. Mucoid changes in the connective tissue of the heart
valves and aorta lead to congestive heart failure and death.
Type III (Osteogenesis Imperfecta Progressively Deforming with Normal Sclerae):
Believed to be about one eighth as frequent as dominantly inherited
osteogenesis imperfecta with blue sclerae. In this type, dentinogenesis
imperfecta is particularly striking, especially in the primary dentition.
Severe kyphoscoliosis and multiple limb deformities are reported.
Type IV (Osteogenesis Imperfecta with Normal Sclerae): Autosomal dominant
characterized by short stature, often below 5th percentile, hearing loss and
otosclerosis, normal-grayish sclerae, and presence of dentinogenesis
imperfecta. The skull presents wormian bones. Onset ...