[Basal cell nevus syndrome: the interface between dentistry and dermatology]. / Het basaalcelnaevussyndroom: raakvlak tussen tandheelkunde en dermatologie.

Basal cell nevus syndrome is a rare, autosomal dominant disorder, predominantly caused by a mutation in the PTCH1 gene. As basal cell carcinomas and keratocysts are the most common abnormalities, dermatologists, orofacial maxillary surgeons, and dentists play a key role in patient care. From the age of 8, screening for odontogenic keratocysts with an orthopantomogram or MRI is recommended every other year. The intensity increases to annual screening after the development of the first odontogenic keratocyst. If BCNS is caused by an underlying SUFU mutation, screening is not indicated since there are no reports of odontogenic keratocyst in these patients to date. Radiation exposure by, for example, computed tomography, should be minimized as it induces new BCCs. Regular follow-up by a dermatologist for early diagnosis and treatment of (multiple) BCC's is recommended for life.

Non-grafted versus grafted sinus lift procedures for implantation in the atrophic maxilla: a systematic review and meta-analysis of randomized controlled trials.

The aim of this systematic review and meta-analysis was to critically evaluate the currently existing clinical evidence on the efficacy of graftless maxillary sinus membrane elevation for implantation in the atrophic posterior maxilla. A search protocol without limitations to November 2020 was followed by two independent researchers. Randomized controlled trials using the lateral window approach for graftless sinus membrane elevation were included. Uncontrolled, retrospective, non-comparative studies, case reports, and experimental studies in animals or cadavers were excluded. The search identified 2777 studies. Critical selection by two independent researchers then led to the inclusion of a total of nine studies. A risk of bias assessment was applied using the revised Cochrane risk-of-bias tool for randomized trials. A meta-analysis was conducted for seven studies. Results showed a high overall implant survival rate in both the graftless and bone-grafted sinus lift groups (97.92% and 98.73%, respectively). The graftless sinus lift group showed a significantly lower vertical bone height gain, with a mean difference of -1.73mm (P=0.01), and a significantly lower bone density, with a mean difference of -94.7 HU (P<0.001). The implant stability quotient values did not differ significantly between the test and control groups (P=0.07).

[Peripheral truncal blocks-Overview and assessment]. / Periphere Rumpfwandblockaden ­ Übersicht und Bewertung.

By implementation of sonography for regional anesthesia, truncal blocks became more relevant in the daily practice of anesthesia and pain therapy. Due to visualized needle guidance ultrasound supports more safety and helps to avoid complications during needle placement. Additionally, complex punctures are possible that were associated with higher risk using landmarks alone. Next to the blocking of specific nerve structures, interfascial and compartment blocks have also become established, whereby the visualization of individual nerves and plexus structures is not of relevance. The present review article describes published and clinically established puncture techniques with respect to the indications and procedures. The clinical value is reported according to the scientific evidence and the analgesic profile. Moreover, the authors explain potential risks, complications and dosing of local anesthetic agents.

The effect of needle tip tracking on procedural time of ultrasound-guided lumbar plexus block: a randomised controlled trial.

Technology that facilitates performance of deep peripheral nerve blocks is of clinical interest. The Onvision™ is a new device for ultrasonographic needle tip tracking that incorporates an ultrasound sensor on the needle tip that is then represented by a green circle on the ultrasound screen. The primary aim of this study was to investigate the effect of needle tip tracking on procedural time in the first human volunteer study. Secondary outcome measures included: number of hand movements; hand movement path length; block success rate; block onset time; block duration; discomfort experienced by the volunteers; and the anaesthetists' confidence as to whether their block would be successful. Two anaesthetists performed ultrasound-guided lumbar plexus blocks with an out-of-plane technique, with and without the use of needle tip tracking. In total, data from 25 volunteers were studied. Mean (SD) procedural time was 163 (103) s with needle tip tracking and 216 (117) s without (p = 0.10). Hand motion analysis showed that needle tip tracking was associated with a significant decrease in the mean (SD) number of intended needling hand movements (39 (29) vs. 59 (36); p = 0.03) and path lengths (3.2 (3.1) m vs. 5.5 (4.5) m; p = 0.03). No differences were found for any other secondary outcomes. The use of Onvision needle tip tracking did not reduce procedural time for out-of-plane ultrasound-guided lumbar plexus block but did reduce the number of hand movements and path lengths. This may indicate improved needle control but further studies are needed to confirm this finding.

Uncertainties and characteristic limits of counting and spectrometric dosimetry systems.

In the event of a radiological emergency, early and reliable knowledge of radioactivity concentrations is important information for organising countermeasures to protect the general public and emergency workers. This is ensured by all European countries in operating airborne radioactivity and dose rate early warning networks. To increase the provided information, the development of new secondary standards based on scintillation detectors for the measurement of ambient dose rate equivalent was initiated in 2014. This paper shows the state-of-the-art of uncertainties and characteristic limits of low dose rate measurement that can be achieved by scintillation-based detector (CeBr3) and gas-based detectors (a high-pressure ionization chamber, HPIC). The comparison of the devices shows the performance and the metrological potential of the CeBr3 detector: Its uncertainty is already very close to the uncertainty of reference values. Looking at the question how to select a reference instrument, the CeBr3 detector with a special data evaluation is even superior to the HPIC and qualifies therefore as a modern secondary standard: Providing both, dose rate and nuclide information.

Epidural needle insertion : A large registry analysis.

BACKGROUND: Dural puncture, paraesthesia and vascular puncture are the most common complications of epidural catheter insertion. Their association with variation in midline needle insertion depth is unknown. OBJECTIVE: This study evaluated the risk of dural and vascular punctures and the unwanted events paraesthesia and multiple skin punctures related to midline needle insertion depth. MATERIAL AND METHODS: A total of 14,503 epidural catheter insertions including lumbar (L1-L5; n = 5367), low thoracic (T7-T12, n = 8234) and upper thoracic (T1-T6, n = 902) insertions, were extracted from the German Network for Regional Anaesthesia registry between 2007 and 2015. The primary outcomes were compared with logistic regression and adjusted (adj) for confounders to determine the risk of complications/events. Results are presented as odds ratios (OR, [95% confidence interval]). MAIN RESULTS: Midline insertion depth depended on body mass index, sex, and spinal level. After adjusting for confounders increased puncture depth (cm) remained an independent risk factor for vascular puncture (adjOR 1.27 [1.09-1.47], p = 0.002) and multiple skin punctures (adjOR 1.25 [1.21-1.29], p < 0.001). In contrast, dural punctures occurred at significantly shallower depths (adjOR 0.73 [0.60-0.89], p = 0.002). Paraesthesia was unrelated to insertion depth. Body mass index and sex had no influence on paraesthesia, dural and vascular punctures. Thoracic epidural insertion was associated with a lower risk of vascular puncture than at lumbar sites (adjOR 0.39 [0.18-0.84], p = 0.02). CONCLUSION: Variation in midline insertion depth is an independent risk factor for epidural complications; however, variability precludes use of depth as a reliable guide to insertion in individual patients.

Volumetric comparison of autogenous bone and tissue-engineered bone replacement materials in alveolar cleft repair: a systematic review and meta-analysis.

The goal of reconstruction of the alveolar cleft in patients with cleft lip and palate is to improve the quality of tissue, the structural stability, and increase the volume of bone. This study is a systematic review with meta-analysis of volumetric bony filling using autogenous bone and various tissue-engineered bone substitutes. We made an electronic search on MEDLINE, EMBASE, SCOPUS, WEB OF SCIENCE, "grey" publications (materials and research produced by organisations outside traditional channels for commercial or academic publishing and distribution), and relevant cross references according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies that reported the outcomes of volumetric grafting were included in the meta-analysis. Of 1276 studies, 26 were included in the meta-analysis. Pooled analysis of 25 studies that used autogenous bone showed a significant reduction in the volume of the cleft equivalent to 62.0% bone fill (95% CI 54.3 to 69.6), in contrast to 10 studies that used a tissue-engineered material and reported bone filling of 68.7% (95% CI 54.5 to 82.8). The estimated sizes of pooled effects across studies showed that there was no significant difference between the two major intervention groups (p value 0.901). Our statistical analysis showed that autogenous bone grafts did not differ significantly from tissue-engineered materials in their ability to fill clefts. Systematic review registration: International Prospective Register of Systematic Reviews, PROSPERO (CRD42017065045).

Novel spectrometers for environmental dose rate monitoring.

A new generation of dosemeters, based on the scintillators LaBr3, CeBr3 and SrI2, read out with conventional photomultipliers, to be used in the field of environmental gamma-radiation monitoring, was investigated. The main features of these new instruments and especially their outdoor performance, studied by long-term investigations under real weather conditions, are presented. The systems were tested at the reference sites for environmental radiation of the Physikalisch-Technische Bundesanstalt. The measurements are compared with that of well characterized classical dose rate reference instruments to demonstrate the suitability of new spectrometers for environmental dose rate monitoring even in adverse weather conditions. Their potential to replace the (mainly Geiger Müller based) dose rate meters operated in about 5000 European early waning network stations as well as in environmental radiation monitoring in general is shown.

INFLUENCE OF RADON PROGENY ON DOSE RATE MEASUREMENTS STUDIED AT PTB'S RADON REFERENCE CHAMBER.

The responses of electronic dose rate meters were investigated in a large volume radon chamber at PTB in a wide range of radon activity concentrations. The measurements were conducted under controlled laboratory conditions and measured dose rate data are compared with Monte-Carlo simulations. Consequences concerning environmental monitoring are described. A further result is that the direct measurement of the dose rates produced by radon progeny in air is hardly possible in radon atmospheres with high activity concentrations, because the major contribution of measured dose rates is produced by radon progeny on the housing of the dose rate instruments. The latter effect largely depends on the ability of surfaces to absorb radon progeny. The Monte-Carlo simulations revealed quantitative results on the height of the single contributions to the total dose rate measured in the radon chamber. When environmental dose rate measurements are performed, the plate-out on detectors can be neglected.

Structures and Electronic Properties of TinV (n = 1-16) Clusters: First-Principles Calculations.

Structures and electronic properties of TinV (n = 1-16) clusters have been investigated using density functional theory with the generalized gradient approximatio. The calculations have shown that the TinV clusters favor compact spherical structures having similar conformations to the pure Tin clusters. The results show that the vanadium atom remains on the surface when n ⩽ 8 and n = 16, while for n = 9-15, it occupies the endohedral position. The Ti6V, Ti12V, and Ti14V clusters are found to be more stable than their neighbors, consistent with pure Tin clusters that have the same size. Additionally Ti4V has been found to be also magic, consistent with recent reports of B- and Al-doped Ti clusters. Small TinV (n ⩽ 4) clusters exhibit a transition from metallic-like to semimetallic electronic structure, while for n = 5 onward, no significant changes are observed compared with pure Tin clusters.

Tunnelling of thoracic epidural catheters is associated with fewer catheter-related infections: a retrospective registry analysis.

BACKGROUND: Catheter-related infections are a serious complication of continuous thoracic epidural analgesia. Tunnelling catheters subcutaneously may reduce infection risk. We thus tested the hypothesis that tunnelling of thoracic epidural catheters is associated with a lower risk of catheter-related infections. METHODS: Twenty-two thousand, four hundred and eleven surgical patients with continuous thoracic epidural analgesia included in the German Network for Regional Anaesthesia registry between 2007 and 2014 were grouped by whether their catheters were tunnelled (n=12 870) or not (n=9541). Catheter-related infections in each group were compared with Student's unpaired t and χ(2) tests. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated with logistic regression, adjusting for potential confounding factors, including age, ASA physical status score, use of catheter for ≥4 days, multiple skin puncture, hospital, and surgical department. RESULTS: There were fewer catheter-related infections in patients with tunnelled catheters (4.5 vs 5.5%, P<0.001). Mild infections were also less common (4.0 vs 4.6%, P=0.009), as were moderate infections (0.4 vs 0.8%, P<0.001). After adjustment for potential confounding factors, tunnelling remained an independent prevention for any grade of infection (adjusted OR 0.51, 95% CI 0.42-0.61, P<0.001) and for mild infections (adjusted OR 0.54, 95% CI 0.43-0.66, P<0.001) and moderate and severe infections (adjusted OR 0.44, 95% CI 0.28-0.70, P=0.001). CONCLUSION: Tunnelling was associated with a lower risk of thoracic epidural catheter-related infections.

Size and structure effects of PtN (N = 12 - 13) clusters for the oxygen reduction reaction: First-principles calculations.

Size and structure effects on the oxygen reduction reaction on PtN clusters with N = 12-13 atoms have been investigated using periodic density functional theory calculations with the generalized gradient approximation. To describe the catalytic activity, we calculated the O and OH adsorption energies on the cluster surface. The oxygen binding on the 3-fold hollow sites on stable Pt12-13 cluster models resulted more favorable for the reaction with O, compared with the Pt13(Ih) and Pt55(Ih) icosahedral particles, in which O binds strongly. However, the rate-limiting step resulted in the removal of the OH species due to strong adsorptions on the vertex sites, reducing the utility of the catalyst surface. On the other hand, the active sites of Pt12-13 clusters have been localized on the edge sites. In particular, the OH adsorption on a bilayer Pt12 cluster is the closest to the optimal target; with 0.0-0.2 eV weaker than the Pt(111) surface. However, more progress is necessary to activate the vertex sites of the clusters. The d-band center of PtN clusters shows that the structural dependence plays a decisive factor in the cluster reactivity.

Peripheral nerve blocks on the upper extremity: Technique of landmark-based and ultrasound-guided approaches.

The German Society of Anaesthesiology and Intensive Care Medicine (Deutsche Gesellschaft für Anästhesiologie und Intensivmedizin, DGAI) established an expert panel to develop preliminary recommendations for the application of peripheral nerve blocks on the upper extremity. The present recommendations state in different variations how ultrasound and/or electrical nerve stimulation guided nerve blocks should be performed. The description of each procedure is rather a recommendation than a guideline. The anaesthesiologist should select the variation of block which provides the highest grade of safety according to his individual opportunities. The first section comprises recommendations regarding dosages of local anaesthetics, general indications and contraindications for peripheral nerve blocks and informations about complications. In the following sections most common blocks techniques on the upper extremity are described.

Obesity in regional anesthesia--a risk factor for peripheral catheter-related infections.

BACKGROUND: Obesity is believed to increase the risk of surgical site infections and possibly increase the risk of catheter-related infections in regional anesthesia. We, therefore, analyzed the influence of obesity on catheter-related infections defined within a national registry for regional anesthesia. METHODS: The German Network for Regional Anesthesia database with 25 participating clinical centers was analyzed between 2007 and 2012. Exactly, 28,249 cases (13,239 peripheral nerve and 15,010 neuraxial blocks) of patients ≥ 14 years were grouped in I: underweight (BMI 13.2-18.49 kg/m(2) , n = 597), II: normal weight (BMI 18.5-24.9 kg/m(2) , n = 9272), III: overweight (BMI 25.0-29.9 kg/m(2) , n = 10,632), and IV: obese (BMI 30.0-70.3 kg/m(2) , n = 7,744). The analysis focused on peripheral and neuraxial catheter-related infections. Differences between the groups were tested with non-parametric ANOVA and chi-square (P < 0.05). Binary logistic regression was used to compare obese, overweight, or underweight patients with normal weight patients. Odds ratios (OR and 95% confidence interval) were calculated and adjusted for potential confounders. RESULTS: Confounders with significant influence on the risk for catheter-related infections were gender, age, ASA score, diabetes, preoperative infection, multiple skin puncture, and prolonged catheter use. The incidence (normal weight: 2.1%, obese: 3.6%; P < 0.001) and the risk of peripheral catheter-related infection was increased in obese compared to normal weight patients [adjusted OR: 1.69 (1.25-2.28); P < 0.001]. In neuraxial sites, the incidence of catheter-related infections differed significantly between normal weight and obese patients (normal weight: 3.2%, obese: 2.3%; P = 0.01), whereas the risk was comparable [adjusted OR: 0.95 (0.71-1.28); P = 0.92]. CONCLUSION: This retrospective cohort study suggests that obesity is an independent risk factor for peripheral, but not neuraxial, catheter-related infections.

[Seeing more : Technical innovations in regional anesthesia]. / Mehr sehen : Technische Innovationen in der Regionalanästhesie.

Visualization and verification are key factors since the implementation of ultrasound-guided regional anesthesia. This article reviews and discusses newer technical innovations in regional anesthesia with regard to optimization of needle guidance, improvements in needle visibility, technical improvements in ultrasound techniques and innovative technologies in regional anesthesia. Clinically available applications are presented as well as experimental tools and techniques with a potential for clinical implementation in the future. Mechanical needle guides are used to improve alignment of needle axis and ultrasound beam axis. Compound imaging technology improves needle visibility in steep needle insertion angles and is already implemented in daily clinical practice. Sonoelastography improves tissue discrimination and detection of small amounts of fluids. Benefits of 3D and 4D ultrasound in regional anesthesia are discussed as well as experimental tools for tissue discrimination, such as optical reflection spectrophotometry.

[Perioperative pain management: what is evidence based?]. / Perioperatives Schmerzmanagement - was ist evidenzbasiert?

BACKGROUND: Adequate post-operative acute pain therapy after spinal surgical procedures is essential for many patients. However, patients already receiving chronic opioid therapy pre-operatively present a special challenge for the treating physician during the post-operative period when managing their acute pain. The team must consider multiple approaches of acute pain management and it is important to proceed according to current evidence-based methods. THERAPY: A wide spectrum of options for pain management after spinal surgery is currently available. This includes various therapeutic methods as well as regional anesthesia. Considering the various options, the method of choice for post-operative analgesia depends on the expected pain, therapy effectiveness, and the applicability with regard to potential side-effects. METHOD: In addition to the basic analgesic therapy consisting of opioid and non-opioid drugs, chronic pain patients may require co-analgesics or combination analgesics from this class. CONCLUSION: Regional anesthesia is currently the predominant method of choice for post-operative acute pain management. Neuraxial blockage is especially important when considering all spinal procedures.

Nerve localization for peripheral regional anesthesia. Recommendations of the German Society of Anaesthesiology and Intensive Care Medicine.

The German Society of Anaesthesiology and Intensive Care Medicine (Deutsche Gesellschaft für Anästhesiologie und Intensivmedizin, DGAI) established an expert panel to develop preliminary recommendations for nerve localization in peripheral regional anesthesia. Based on expert knowledge and the relatively limited data, the recommendations state how ultrasound and/or electrical nerve stimulation should be used in daily practice, and where and when local anesthetics should be injected. Moreover, it was defined under which conditions a peripheral nerve block under general anesthesia or deep sedation is applicable.Regarding the use of ultrasound the expert opinion was that out-of-plane and in-plane-techniques can be considered equal with respect to patient safety. Nevertheless, the direct or indirect visualization of the needle tip has to be assured. The injection of local anesthetics has to be visualized. Injections into nerves or those requiring an injection pressure should be avoided. The sole use of electrical nerve stimulation or ultrasound for nerve localization is still a suitable option as well as their combined use. To avoid accidental intraneural needle placement, an electrical current threshold ≥ 0.5 mA should be used. Moreover, it was stated that peripheral nerve blocks or continuous nerve block techniques under sedation or general anesthesia are applicable in adult patients who are unable to tolerate the block being performed in an awake state or have difficulty cooperating.This article is published in English.