Also called posterior plagiocephaly
Lambdoid synostosis is the form of synostosis most commonly mistaken for posterior positional deformational plagiocephaly and must be closely evaluated. Unilateral lamdoid synostosis results in flattening of the back of the head on the affected side as well as compensatory growth of the mastoid process on the same side (ipsilateral mastoid bulge). This leads to a characteristic and unique “tilt” in the cranial base. This differentiates it from positional/deformational plagiocephaly. The ear on the affected side is often deviated back and toward the fused suture. This is one of the rarest types of craniosynostosis, accounting for only 2-4% of synostosis cases. Surgical management of lambdoid synostosis involves restructuring the posterior fossa to provide adequate space for normal brain development as well as restoring normal symmetry.