Clinical Features and the Use of Three-Dimensional Imaging for Unilateral Lambdoid Synostosis.

INTRODUCTION: True isolated lambdoid craniosynostosis is rare. It requires corrective surgery to prevent intracranial pressure and aesthetic stigma by significant dyscrania. We summarize our case series for lambdoid craniosynostosis outlining the pathophysiology, clinical findings and surgical approaches and outcomes. METHODOLOGY: A retrospective analysis of our data from 2010 to 2020 summarized our cases of true lambdoid synostosis. We have used the medical notes and the radiological findings from computed tomography scans to summarize a case series of isolated lambdoid synostosis. RESULTS: Our case series demonstrated 7 patients with true isolated lambdoid craniosynostosis. In most cases surgical intervention in the form of posterior cranial vault remodeling utilizing a bandeau, based on occipital advancement techniques, has demonstrated the most consistently favorable aesthetic outcome. CONCLUSIONS: Surgical referral to a craniofacial center should be sought early in difficult to diagnose cases. Although rare, surgical intervention is indicated to correct potentially increased intracranial pressure and to ameliorate cranial dyscrania.

FACE-Q Craniofacial Module: Part 1 validation of CLEFT-Q scales for use in children and young adults with facial conditions.

BACKGROUND: The CLEFT-Q includes 12 independently functioning scales that measure appearance (face, nose, nostrils, teeth, lips, jaws), health-related quality of life (psychological, social, school, speech distress), and speech function, and an eating/drinking checklist. Previous qualitative research revealed that the CLEFT-Q has content validity in noncleft craniofacial conditions. This study aimed to examine the psychometric performance of the CLEFT-Q in an international sample of patients with a broad range of facial conditions. METHODS: Data were collected between October 2016 and December 2019 from 2132 patients aged 8 to 29 years with noncleft facial conditions. Rasch measurement theory (RMT) analysis was used to examine Differential Item Function (DIF) by comparing the original CLEFT-Q sample and the new FACE-Q craniofacial sample. Reliability and validity of the scales in a combined cleft and craniofacial sample (n=4743) were examined. RESULTS: DIF was found for 23 CLEFT-Q items when the datasets for the two samples were compared. When items with DIF were split by sample, correlations between the original and split person locations showed that DIF had negligible impact on scale scoring (correlations ≥0.995). In the combined sample, RMT analysis led to the retention of original content for ten CLEFT-Q scales, modification of the Teeth scale, and the addition of an Eating/Drinking scale. Data obtained fit with the Rasch model for 11 scales (exception School, p=0.04). Person Separation Index and Cronbach alpha values met the criteria. CONCLUSION: The scales described in this study can be used to measure outcomes in children and young adults with cleft and noncleft craniofacial conditions.

Matrix metalloproteinases and their inhibitors in bone remodelling following distraction osteogenesis of the sheep mandible.

AIM: Matrix metalloproteinases (MMPs), together with their tissue inhibitors (TIMPs), are responsible for the controlled degradation of collagen and other matrix substrates in bone and other tissues. This study evaluated the expression of MMPs and TIMPs in bony remodelling in a bilateral sheep mandible model up to 12 months following lengthening by distraction osteogenesis. METHODOLOGY: Sheep mandibles were harvested 3, 6, 9 or 12 months following lengthening by bilateral mandibular distraction (1 mm/day for 20 days). Undistracted sheep mandibles were used as controls. The tissues underwent routine histology and immunohistochemical staining with monoclonal antibodies specific to MMPs 1-3 and TIMP-1, 2. Matrix and cell staining was assessed using a semi-quantitative analysis. RESULTS: Matrix metalloproteinases and their tissue inhibitors (TIMPs) expression levels were marked at 3 months and decreased thereafter becoming similar to undistracted controls by 12 months. The histologic development of mature lamellar cortical bone was similar to undistracted controls by 9 months following distraction. CONCLUSIONS: A temporal expression of MMPs and TIMPs was found in distraction osteogenesis. MMPs and TIMPS may, in part, reflect the state of bony remodelling following mandibular lengthening by distraction osteogenesis. Matrix metalloproteinases and TIMP expression were comparable to undistracted controls by 12 months, suggesting that equilibrium had been achieved and that bony relapse is unlikely.

A compliant tip reduces the peak pressure of laparoscopic graspers.

BACKGROUND: Previous studies have demonstrated that high pressures are generated at the tips of laparoscopic graspers, which can cause tissue injury. This study examines the effect of a compliant edge on tip pressure. METHODS: One of a pair of identical laparoscopic graspers was modified by refashioning the tip out of silicone. A thin film pressure transducer (I-scan 6900 sensor) was deployed between the jaws of the grasper and a simulated tissue (leather strap). Load and handle pressures were kept constant. Peak tip pressure readings were taken as the load orientation was increased from the perpendicular to 135 degrees (n = 10). The data was analysed using anova and a post-hoc Duncan's multiple range test. RESULTS: Peak tip pressures generated by the compliant tipped grasper were significantly less than those developed by the unmodified grasper, particularly at high-load orientations. CONCLUSION: High pressures generated at the tip of laparoscopic graspers can be reduced by altering the mechanical properties (compliance) of the tip.