Cloverleaf Skull

Cloverleaf skull (kleeblattschadel) occurs when there is intrauterine premature closure of all but the squamosal suture. It is classically seen with type 2 thanatophoric dysplasia, but can also be seen with severe Apert and Crouzon syndromes.

Thanatophoric dysplasia is the second most common lethal neonatal skeletal dysplasia (osteogenesis imperfecta type II is the most common). There is rhizomelia, with shortening of the humeri and femurs. Patients have very short ribs that do not extend anteriorly, and H- or U-shaped vertebral bodies.

Patients with Apert syndrome have craniosynostosis, usually of the coronary suture, and symmetric syndactyly of more than two digits involving the upper and lower extremities.

References

• Carneiro GV et al. Apert syndrome: review and report a case. Braz J Otorhinolaryngol 2008; 74(4):640.
• Glass RBJ et al. The Infant Skull: A Vault of Information. RadioGraphics 2004;24:507-522.
• Glass RBJ et al. Pediatric Ribs: A Spectrum of Abnormalitie. RadioGraphics 2002; 22: 87-104.