Type three OI also has bones that fracture easily. Fractures are often present at birth, they tend to be mostly of short stature. Sclera has a purple, blue or gray tint. Loose joints and poor muscle development in arms and legs are common. Barrel shaped rib cage, triangular face, spinal curvature, respiratory problems are also possible.
Bone deformity is often severe.
The possibility of brittle teeth and hearing loss. The collagen in Type III is improperly formed. Type four is between type one and type three in severity. People with type four bones fracture easily, most before puberty. The bone deformity is mild to moderate, but they have the tendency toward spinal curvature.