Progressive postnatal pansynostosis is a rare form of craniosynostosis characterized by late fusion of all cranial sutures. 

This type of craniosynostosis occurs insidiously after birth and presents later in life, unlike other types of craniosynostosis which occur during the prenatal period. 

The late fusion of cranial sutures means that the diagnosis is delayed and typically presents with signs of increased intracranial pressure with a rather normal, albeit smaller than average, head size.

The sagittal suture typically closes at around 22 years of age; the coronal suture closes at around 24 years; and the lambdoid and squamosal sutures close at around 26 and 60 years, respectively.¹