Sagittal synostosis: II. Cranial morphology and growth after the modified pi-plasty

The aim of this study was to characterise the postoperative cranial growth and morphology after a modified pi-plasty for sagittal synostosis. The shape of the skull of 82 patients with isolated premature synostosis of the sagittal suture ( SS group) operated on with a modified pi-plasty was studied longitudinally. Forty-five children with unilateral incomplete cleft lip (UICL), evaluated longitudinally at the ages of 2.4 and 23.2 months were used as controls. A standardised radiocephalometric technique was used for image acquisition. The radiocephalograms were analysed using a modification of a method developed by Kreiborg, which included the digitisation of 89 landmarks of the calvaria, cranial base, and orbit ( 43 in the lateral and 46 in the frontal projections), the production of mean shape plots for each group, and the intergroup comparison of a series of 78 variables ( linear distance between selected landmarks, and angles defined by groups of three landmarks). Paired and unpaired t tests were used to assess the differences between the variables studied. These were accepted as significant for values of p