A new technique of using implantable springs as an adjunct after corrective surgery for craniofacial malformations is presented. A 6-month-old boy with multiple premature craniosynostoses and extreme turricephaly underwent surgery of limited extensiveness but supplemented with a set of indwelling springs for gradual postoperative skull reshaping. At spring removal three months later the skull was normalised both clinically and on cephalogram. A 5-year-old boy with Apert syndrome, severe midface retrusion, exorbitism, and sleep apnoea underwent a monobloc full face disjunction without repositioning, but was fitted with two springs for postoperative facial advancement. Three months postoperatively cephalometric analysis revealed 14 mm advancement at incisor level and at least 16 mm in the frontal region. There was no more exorbitism or clinically noticeable midface retrusion. Sleep studies revealed that the sleep apnoea was significantly improved, meaning complete cure except when sleeping flat on the back. It was concluded from these first clinical applications of spring assisted craniofacial distraction that springs hold significant promise for the future in many respects.

The aim of the study was to evaluate the modified pi-plasty procedure for the treatment of sagittal synostosis, assessing the issues of safety, complications, morphological outcome, and degree of parental satisfaction. A retrospective evaluation of 110 patients with nonsyndromal single suture sagittal synostosis operated on with the modified pi-plasty procedure was undertaken. Cephalometric radiographs were obtained preoperatively and postoperatively at ages 3 and 5 years in three standardized projections. The Cephalic Index and the Axial Width Ratio were determined and used as objective outcome measures. An evaluation of the radiographic digital markings was carried out using a Beaten Copper Score. A parental questionnaire was used to obtain a subjective esthetical outcome assessment. The patient population consisted of 76% boys and 24% girls with a 20% incidence of a positive familial history of craniosynostosis. The mean age at surgery was 7.73 months. Morbidity from the procedure was minimal and there were no mortalities. The Cephalic Index changed from a mean preoperative value of 65% to a postoperative mean value of 72% (P = 0.00004). The mean Axial Width Ratio changed from a preoperative 80% to 72% at the 3-year evaluation (P = 0.00029). The Beaten Copper score changed from a mean preoperative value of 2.35 to 5.42 postoperatively at 3 years (P = 0.00001). The response rate to the questionnaire was 86%, and there were significant postoperative improvements in all studied aspects of the skull shape. The modified pi-plasty is a safe technique, and it induces significant objective changes in skull morphology toward normality. It also yields a high degree of parental satisfaction with regard to aesthetic outcome, as evaluated by a written questionnaire.

No abstract

High-resolution magnetic-torque studies on an untwinned YBa 2 Cu 3 O 72d single crystal near its critical temperature T c reveal that the first-order vortex-lattice melting transition (VLMT) persists at least up to 0.5 K below T c . The associated sharp discontinuity in magnetization is detectable even at temperatures where the torque signal deviates from mean-field behavior due to fluctuations. The magnetic irreversibility at the VLMT can be suppressed by applying a weak transverse ac magnetic field. This offers the possibility of separating the irreversibility line from the melting line near T c .[S0031-9007(98)07569-3]

We study numerically and experimentally the dynamics of driven vortex matter. Our London-Langevin simulations find that the critical current exhibits a peak both across the Bragg glass to vortex glass transition and across the melting line. The peak is accompanied by a clear crossing of the I-V curves. We report transport measurements on untwinned YBCO crystals, in complete accordance with these findings. At higher drives disorder is averaged to reduced values, and in three dimensions the vortices reorder into a "moving solid." The effect of the disorder can be well represented with a "shaking temperature" which is inversely proportional to the velocity.