Symmetry recovery in zygomaticomaxillary complex fractures compared to normal unfractured population: A new reliable 3D evaluation.

OBJECTIVE: This study aims to quantify the facial symmetry of surgically treated zygomaticomaxillary complex (ZMC) fractures through a new reliable three-dimensional evaluation method, which is crucial for improving post-operative aesthetic and functional outcomes. MATERIAL AND METHODS: Healthy patients and patients with surgically treated ZMC fractures were retrospectively reviewed. Using Brainlab Elements® the zygomatic bone and the orbit of each patient was segmented and mirrored. Subsequently, the mirrored side was matched with the other side via volume-based registration, using the segmented orbit as reference. Volumetric asymmetry was measured using 3-matic software, and a surface-based matching technique was used to calculate the mean absolute differences (MAD) between the surfaces of the two sides of the ZMC. The reliability of this novel method using volume-based registration was tested, and the intra-class correlation coefficient was assessed. RESULTS: The MAD between the surfaces of the left and right sides in the control group was 0.51 mm (±0.09). As for the ZMC fracture group, MAD was 0.78 mm (±0.20) and 0.72 mm (±0.15) pre- and post-operatively, respectively. The MAD showed statistically significant differences between pre- and post-operative groups (p = 0.005) and between control and post-operative groups (p < 0.001). The intra-class correlation coefficient was high (≥0.99). CONCLUSIONS: This evaluation method using mirroring and volume-based registration to determine the symmetrical position of the ZMC is reliable. The surface-based measurements revealed an improved symmetry after surgery. However, the symmetry of the treated patients remained lower than the control group.

Semi-automatic magnetic resonance imaging based orbital fat volumetry: reliability and correlation with computed tomography.

Post-processing analysis can provide valuable information for diagnosis and planning of orbital disorders. This cross-sectional study aims to evaluate the reliability of semi-automatic, orbital fat volumetry using magnetic resonance imaging (MRI). Two observers assessed the orbital fat volume using a standard MRI protocol (3T, T1w sequence) in 12 orbits diagnosed with Graves' orbitopathy (GO) and 10 healthy control orbits. MRI and computed tomography (CT) based analysis were compared. Intra-observer variability was good (intraclass correlation coefficient (ICC) 0.88; 95% confidence interval (CI) [0.70, 0.95]) and interobserver agreement was moderate (ICC 0.55; 95% CI [-0.09, 0.81]), which corresponds to a mean percentage difference of 1.3% and 17.9% of the total orbital fat volume. Mean differences between MRI and CT measurements were, respectively, 1.1 cm3 (P= 0.064, 95% CI [-0.20, 2.43]) and 1.4 cm3 (P=0.016, 95% CI [0.21, 2.56]) for the control and the GO group. MRI volumetry was strongly correlated with CT (Pearson's r= 0.7, P<0.001). We conclude that orbital fat volumetry is feasible with a semi-automatic segmentation procedure and standard MRI protocol. Correlation with CT volumetry is good, but considerable bias may derive from observer variability and these errors should be taken into account for the purpose of volumetric analysis. Better definition of error sources may increase measurement accuracy.

Digital surface scanning in flap perfusion.

Monitoring vascular perfusion of transferred tissue is essential in reconstructive surgery to recognize early flap failure. The aim of this study was to evaluate the ability of a digital surface scanner to detect vascular perfusion disorders through the monitoring of skin colour changes. A total of 160 surface scans of the forearm skin were performed with a TRIOS 3D scanner. Vascular compromise was simulated at different time-points by intermittent occlusion of the blood supply to the forearm skin (first the arterial blood supply and then the venous blood supply). Skin colour changes were examined according to the hue, saturation, and value colour scale. Colour differences were analysed with a paired t-test. Significant differences were observed between the colour of the normal skin and that of the vascular compromised skin (P<0.01). The surface scanner could distinguish between arterial occlusion and venous congestion (P<0.01). A digital surface scan is an objective, non-invasive tool to detect early vascular perfusion disorders of the skin.

Efficacy and complications of orbital fat decompression in Graves' orbitopathy: a systematic review and meta-analysis.

In Graves' orbitopathy, surgical decompression is often needed for functional and aesthetic reasons. This meta-analysis was performed to assess the efficacy and safety of fat removal orbital decompression (FROD) alone to treat exophthalmos in Graves' orbitopathy. A systematic search was conducted in PubMed/MEDLINE, Web of Science, and Cochrane Library for studies published before August 2018. Random-effects meta-analyses were applied; weighted means and weighted proportions with corresponding 95% confidence intervals (CI) were calculated. Study quality and quality of evidence for each individual outcome were analyzed. Of 1908 records initially identified, 13 observational studies were selected, representing 4820 orbits in 2514 patients. Weighted Hertel exophthalmometry was 23.10mm (95% CI 21.77-24.43mm) preoperative and 19.31mm (95% CI 17.81-20.81mm) postoperative. The weighted mean difference was 3.81mm (95% CI 3.41-4.21mm). Five studies reported an improvement of diplopia after surgery, occurring in 943 of 1172 patients (weighted proportion 0.50, 95% CI 0.15-0.85). Persistent new onset diplopia was reported in five studies, or 124 of 1277 patients (weighted proportion 0.15, 95% CI 0.03-0.27). No serious adverse events were reported. Results support the effectiveness and safety of FROD to treat mild-to-moderate exophthalmos in Graves' orbitopathy. Prospective and controlled trials are needed to improve the level of evidence.

Does intensity-modulated radiation therapy lower the risk of osteoradionecrosis of the jaw? A long-term comparative analysis.

The aim of this study was to analyze the impact of different radiation techniques on the long-term incidence of osteoradionecrosis in head and neck cancer. Risk factors and the occurrence of osteoradionecrosis were analyzed in a retrospective, comparative, observational study. Medical files and radiological images of 109 patients treated with primary intensity-modulated radiation therapy (IMRT) and 129 patients treated with primary three-dimensional conformal radiotherapy (3D-CRT) were evaluated. Proportional hazards models were used to analyse the effects of the radiation modality and patient characteristics on the necrosis risk. Twenty-two patients developed osteoradionecrosis (9.2%) during a mean follow-up of 4.3 years. A numerical difference was observed, with more osteoradionecrosis after 3D-CRT (n=18) than after IMRT (n=4). After correction for group differences and confounders, no statistical difference in risk was observed between the two treatment groups (P=0.37). Multivariate analysis showed evidence of a higher osteoradionecrosis risk for patients with a tumour of the oropharynx and for patients with tooth extraction after radiation therapy. Although the incidence of osteoradionecrosis tended to be lower after IMRT, due to the multifactorial aetiology it remains a severe problem and cannot be prevented by new radiotherapy techniques. Continuous efforts are necessary to control additional risk factors and avoid osteoradionecrosis.

De novo variants in CDK13 associated with syndromic ID/DD: Molecular and clinical delineation of 15 individuals and a further review.

De novo variants in the gene encoding cyclin-dependent kinase 13 (CDK13) have been associated with congenital heart defects and intellectual disability (ID). Here, we present the clinical assessment of 15 individuals and report novel de novo missense variants within the kinase domain of CDK13. Furthermore, we describe 2 nonsense variants and a recurrent frame-shift variant. We demonstrate the synthesis of 2 aberrant CDK13 transcripts in lymphoblastoid cells from an individual with a splice-site variant. Clinical characteristics of the individuals include mild to severe ID, developmental delay, behavioral problems, (neonatal) hypotonia and a variety of facial dysmorphism. Congenital heart defects were present in 2 individuals of the current cohort, but in at least 42% of all known individuals. An overview of all published cases is provided and does not demonstrate an obvious genotype-phenotype correlation, although 2 individuals harboring a stop codons at the end of the kinase domain might have a milder phenotype. Overall, there seems not to be a clinically recognizable facial appearance. The variability in the phenotypes impedes an à vue diagnosis of this syndrome and therefore genome-wide or gene-panel driven genetic testing is needed. Based on this overview, we provide suggestions for clinical work-up and management of this recently described ID syndrome.

Expansion and further delineation of the SETD5 phenotype leading to global developmental delay, variable dysmorphic features, and reduced penetrance.

Diagnostic exome sequencing (DES) has aided delineation of the phenotypic spectrum of rare genetic etiologies of intellectual disability (ID). A SET domain containing 5 gene (SETD5) phenotype of ID and dysmorphic features has been previously described in relation to patients with 3p25.3 deletions and in a few individuals with de novo sequence alterations. Herein, we present additional patients with pathogenic SETD5 sequence alterations. The majority of patients in this cohort and previously reported have developmental delay, behavioral/psychiatric issues, and variable hand and skeletal abnormalities. We also present an apparently unaffected carrier mother of an affected individual and a carrier mother with normal intelligence and affected twin sons. We suggest that the phenotype of SETD5 is more complex and variable than previously presented. Therefore, many features and presentations need to be considered when evaluating a patient for SETD5 alterations through DES.

Association of the missense variant p.Arg203Trp in PACS1 as a cause of intellectual disability and seizures.

Graphical abstract key: ADHD, attention deficit hyperactivity disorder; ASD, atrial septal defect; DD, developmental delay; EEG, electroencephalogram; Ht, height; ID, intellectual disability; OCD, obsessive-compulsive disorder; OFC, open fontanelle; PDA, patent ductus arteriosis; PFO, patent foramen ovale; VSD, ventricular septal defect; Wt, weight.

The dynamic behaviour of yeast cells immobilised in porous glass studied by membrane mass spectrometry.

Membrane mass spectrometry (MMS) with reduced sample withdrawal has been used to investigate the metabolic activity of yeast cells immobilised in porous glass. An adapted MS membrane inlet reactor with a polyethylene terephthalate barrier membrane has been constructed for this purpose. In a first experiment, the mass transport of O2 in a porous glass disc under well-defined experimental conditions has been studied by determining the apparent effective diffusion coefficient. The behaviour of immobilised Saccharomyces cerevisiae has been monitored by the MMS measurement of O2 and CO2 after applying a step in glucose concentration. Free-cell kinetic parameters were used in a dynamic reaction-diffusion model to simulate the O2 consumption curve. The theoretical and experimental curve showed comparable behaviour, which means that the immobilisation of yeast cells in porous glass has no substantial effect on its growth kinetics.

Growth kinetics of gel-immobilized yeast cells studied by on-line microscopy.

A 'microscope reactor' was used to study on-line the dynamics of gel immobilized cell systems. The applicability of the reactor is demonstrated by a study of the growth kinetics of Saccharomyces cerevisiae entrapped in 2% calcium alginate. The specific growth rates of single immobilized cells and free cells were measured. The growth of a microcolony in Ca-alginate was followed and the specific growth rate of the cells in the microcolony determined. A simple growth model was used to estimate the cell volume fraction of the yeast cells in the microcolony. As internal and external mass transfer limitations can be neglected and immobilized cell growth rates were found to be identical to those of free cells, one may conclude that immobilization does not influence cell growth under our experimental conditions.

Reaction and diffusion in a gel membrane reactor containing immobilized cells.

To investigate the effect of diffusional limitations and heterogeneous cell distribution in a gel-immobilized cell system, a gel membrane reactor has been constructed. The reactor consists essentially of a gel layer with immobilized cells, flanked by two well-mixed chambers. Through one chamber substrate is pumped, and this chamber is the equivalent of the outside of a spherical gel bead. The second closed measuring chamber contains a small quantity of liquid that can equilibrate with the inside surface of the membrane, eventually after a long transient. Analysis of the liquid in this chamber can give direct information on substrate and product concentrations at the gel surface, and is and indication of the situation in the center of a gel bead. The gel membrane reactor appears to be an excellent tool to study diffusion and reaction in a gel-containing immobilized cells. A mathematical model with time- and position-dependent cell concentration and diffusion coefficient is described. Experimental data show the effective diffusion coefficient of glucose in an alginate gel to decrease with yeast cell concentration. Moreover, kinetic parameters could be determined, using the mathematical model. Microscopic analysis confirmed the proliferation of the gel-entrapped microorganisms in the outer layer of the matrix, as predicted by the model. Potentially, this type of reactor has a clear potential to study the physiology of gel-immobilized cells.