Asterion region synostosis.

Posterior plagiocephaly historically has been associated with synostosis of the lambdoid suture. The incidence, diagnosis, and modes of treatment for stenosis of the lambdoid suture remain controversial. Commonly, the lambdoid suture is found to be open both on radiographic examination and at the time of surgery. The study reports on nine patients who presented with unilateral posterior plagiocephaly and who were found to have open lambdoid sutures, but a stenosed region of the asterion. The area of involvement included the distal-most lambdoid suture, the parietomastoid, occipitomastoid, and proximal squamosal sutures. Positional molding or torticollis was ruled out in all patients. All the patients showed progressive involvement of the skull base, including anterior shifts of the ipsilateral ear, compensatory ipsilateral frontal bossing and malar protrusion. Stenosis of the asterion was diagnosed with three-dimensional computed tomography scans, corroborated at the time of surgery and confirmed histologically. Surgical correction involved resection of the affected asterion and reconstruction using a bandeau-technique, barrel staves of the occipital bone and bone graft transposition. This approach provided excellent esthetic results in all patients.