infantile cortical hyperostosis, a familial disorder characterized in an infant by subperiosteal bone formation over many bones, causing swellings and tenderness in the affected areas. The child also tends to be feverish and irritable. The mandible is most commonly involved. Radiographs indicate areas of new bone growth beneath the periosteum. The disorder appears before 6 months of age and disappears during childhood. Also called Caffey’s disease.