Evaluation of digital construction, production and intraoral position accuracy of novel 3D CAD/CAM titanium retainers

OBJECTIVES

New opportunities have arisen to manufacture three-dimensional computer-aided design/computer-aided manufacturing (3D CAD/CAM) retainers from titanium blocks by digital cutting technology. These novel technologies need to fulfill requirements regarding digital planning and position accuracy. The aim of the present study was to investigate the digital construction, the CAD/CAM production and the intraoral positioning accuracy of custom-manufactured novel 3D CAD/CAM titanium retainers.

MATERIALS AND METHODS

A total of 37 prime4me® RETAIN3R (Dentaurum, Ispringen, Germany) retainers were inserted to stabilize the upper anterior front teeth. Following insertion, an intraoral scan was used to record the position. The intraoral position was compared to the virtual setup using 3D superimposition software. Measurement points were evaluated in all three dimensions (horizontal, sagittal and vertical planes). Data were analyzed using Kruskal-Wallis test followed by Dunn's multiple comparison test.

RESULTS

A total of 185 measurements were performed. The horizontal plane and the sagittal plane demonstrated a high level of positioning accuracy between the planned and the intraoral position. Statistically significant deviations between the preceding virtual setup and the intraoral situation were observed in the vertical dimension. Within the retainer, the intraoral positioning accuracy decreased for the measurement points in the direction of the distal retainer segment.

CONCLUSION

Based on the results, the present study shows a high level of congruence between the 3D virtually planning and the final intraoral position of the fabricated novel 3D CAD/CAM titanium retainers.

Systematic Outline of Errors of Statistical Inference

A systematic outline is given of the errors and mistakes which can affect statistical inference. This study starts from the subject matter question and discusses the possibilities of errors during all steps of work up to the wording of the statistical result and the inference to the original problem.

Einführung in die Methoden der ätiologischen Forschung - Statistik und Dokumentation -

Der Begriff Einflußfaktor, der den Ursachenbegriff einschließt, wird erläutert. Ein Einflußfaktor muß statistisch nachweisbare Korrelationen (Assoziationen) zur Folge haben. Umgekehrt kann aus dem Vorliegen einer Korrelation zwischen einer Krankheit und einem Faktor nicht ohne weiteres geschlossen werden, daß der Faktor die Entstehung der Krankheit beeinflußt. Die Möglichkeiten für andere, nicht-kausale Deutungen werden ausführlich dargestellt. Die kausale Deutung wird erst durch den Ausschluß anderer Deutungen zwingend.

Ätiologische Untersuchungen bezwecken den Nachweis von Häufungen. Manchmal können zeitliche und örtliche Häufungen ohne spezielle Kontrollreihen nachgewiesen werden. Besonders wichtig sind retrospektive und prospektive Vergleichsreihen, bei denen Kontrollreihen unerläßlich sind. Voraussetzungen und Anforderungen an die Planung, die Beobachtungen und die Dokumentation, ohne deren Erfüllung die Ergebnisse nicht brauchbar sind, werden eingehend besprochen. Subjektive Einflüsse auf die Beobachtung können insbesondere bei retrospektiven Reihen erhebliche systematische Fehler verursachen. Prospektive Reihen sind weniger fehleranfällig, erfordern aber einen erheblich größeren Reihenumfang.

Besonderheiten treten auf, wenn viele Faktoren und Krankheiten systematisch auf Zusammenhänge überprüft werden sollen. Für die Untersuchung von Medikamenten auf Nebenwirkungen wird ein Stichprobenverfahren vorgeschlagen, bei dem jede x-te Packung als Prüfpackung gekennzeichnet wird. Die Ärzte, auf deren Verschreibung diese Packungen zufällig . ausgegeben werden, werden gebeten, das weitere Krankheitsschicksal dieser Patienten zu beobachten und einem sammelnden Institut mitzuteilen. Ein umfassendes Beobachtungssystem dieser Art enthält genügend Vergleichsmaterial, um etwaige Häufungen statistisch beurteilen zu können.

Zum Schlußwirddie Entscheidungslage für das praktische Handeln aufgrund statistisch bestätigter ätiologischer Hypothesen behandelt.

Intercalation behaviour of magnesium into natural graphite using organic electrolyte systems

Use of natural graphite based electrodes as insertion anodes in rechargeable magnesium-ion batteries.

Insight into the photosynthetic apparatus in evergreen and deciduous European oaks during autumn senescence using OJIP fluorescence transient analysis

Climate change is one of the major issues nowadays, and Mediterranean broadleaf species have been suggested to fill possible future gaps created by climate change in Central European forests. To provide a scientific-based foundation for such practical strategies, it is important to obtain a general idea about differences and similarities in the physiology of Central European and Mediterranean species. In the present study, we evaluated the onset of leaf senescence of a broad spectrum of oak species under the Central European climate in a common garden experiment. Degradation of the photosynthetic apparatus of evergreen (Quercus ilex, Q. suber), semi-evergreen (Q.×turneri, Q.×hispanica) and deciduous oaks (Q. robur, Q. cerris, Q. frainetto, Q. pubescens) was monitored as chlorophyll content and analysed chlorophyll fluorescence induction transients. In the deciduous species, a significant decline in chlorophyll content was observed during autumn/winter, with Q. pubescens showing the slowest decline. Analysis of fluorescence induction transients revealed a significant decline in quantum efficiency of the primary photochemistry and reaction centre density and later, a decrease in quantum efficiency of end acceptor reduction. Alterations in fluorescence parameters were compared to the decline in chlorophyll content, which occurred much more slowly than expected from the fluorescence data. The evergreen species showed no decline in chlorophyll content, nor different chlorophyll a fluorescence induction behaviour despite temperature falling below 0 °C. The hybrids showed intermediate behaviour between their parental evergreen and deciduous taxa.

In vivo reflectance confocal microscopy: automated diagnostic image analysis of melanocytic skin tumours

BACKGROUND

In vivo reflectance confocal microscopy (RCM) has been shown to be a valuable imaging tool in the diagnosis of melanocytic skin tumours. However, diagnostic image analysis performed by automated systems is to date quite rare.

OBJECTIVES

In this study, we investigated the applicability of an automated image analysis system using a machine learning algorithm on diagnostic discrimination of benign and malignant melanocytic skin tumours in RCM.

METHODS

Overall, 16,269 RCM tumour images were evaluated. Image analysis was based on features of the wavelet transform. A learning set of 6147 images was used to establish a classification tree algorithm and an independent test set of 10, 122 images was applied to validate the tree model (grouping method 1). Additionally, randomly generated 'new' learning and test sets, tumour images only and different skin layers were evaluated (grouping method 2, 3 and 4).

RESULTS

  The classification tree analysis correctly classified 93.60% of the melanoma and 90.40% of the nevi images of the learning set. When the classification tree was applied to the independent test set 46.71 ± 19.97% (range 7.81-83.87%) of the tumour images in benign melanocytic skin lesions were classified as 'malignant', in contrast to 55.68 ± 14.58% (range 30.65-83.59%; t-test: P < 0.036) in malignant melanocytic skin lesions (grouping method 1). Further investigations could not improve the results significantly (grouping method 2, 3 and 4).

CONCLUSIONS

The automated RCM image analysis procedure holds promise for further investigations. However, to date our system cannot be applied to routine skin tumour screening.

Prevalence and characteristics of meticillin-resistant Staphylococcus aureus in humans in contact with farm animals, in livestock, and in food of animal origin, Switzerland, 2009

A total of 2,662 samples, collected from March to September 2009 in Switzerland, were tested for the presence of meticillin-resistant Staphylococcus aureus (MRSA). The collection comprised nasal swabs from 148 pig farmers, 133 veterinarians, 179 slaughterhouse employees, 800 pigs, 300 calves, 400 cattle, 100 pooled neck skin swabs from chicken carcasses, and 460 food samples of animal origin. Moreover, 142 S. aureus strains, isolated from bovine mastitis milk, were included in the study. Twenty samples (<1%; four veterinarians, 10 pigs, three calves, one young bull, and two mastitis milk samples) tested positive for MRSA. Genotyping of the MRSA strains was performed by multilocus sequence typing, spa- and SCCmec-typing, and revealed ST398 (n=18), ST8 (n=1), ST 1 (n=1), spa types t011 (n=7), t034 (n=11), t064 (n=1), t127 (n=1), and SCCmec types IV (n=4) and V (n=16). The 20 MRSA strains were subjected to antibiotic susceptibility testing and pulsed-field gel electrophoresis using the restriction enzyme EagI. Supplementary PCR reactions were performed to investigate the presence of Panton-Valentine leukocidin and staphylococcal enterotoxins A to D.

Prevalence and characteristics of meticillin-resistant Staphylococcus aureus in humans in contact with farm animals, in livestock, and in food of animal origin, Switzerland, 2009

A total of 2,662 samples, collected from March to September 2009 in Switzerland, were tested for the presence of meticillin-resistant Staphylococcus aureus (MRSA). The collection comprised nasal swabs from 148 pig farmers, 133 veterinarians, 179 slaughterhouse employees, 800 pigs, 300 calves, 400 cattle, 100 pooled neck skin swabs from chicken carcasses, and 460 food samples of animal origin. Moreover, 142 S. aureus strains, isolated from bovine mastitis milk, were included in the study. Twenty samples (< 1%; four veterinarians, 10 pigs, three calves, one young bull, and two mastitis milk samples) tested positive for MRSA. Genotyping of the MRSA strains was performed by multilocus sequence typing, spa- and SCCmec-typing, and revealed ST398 (n=18), ST8 (n=1), ST 1 (n=1), spa types t011 (n=7), t034 (n=11), t064 (n=1), t127 (n=1), and SCCmec types IV (n=4) and V (n=16). The 20 MRSA strains were subjected to antibiotic susceptibility testing and pulsed-field gel electrophoresis using the restriction enzyme EagI. Supplementary PCR reactions were performed to investigate the presence of Panton-Valentine leukocidin and staphylococcal enterotoxins A to D.

Confocal laser scanning microscopy-guided surgery for neurofibroma

The neurofibromatoses comprise at least two separate genetic disorders with variable clinical features and an unpredictable course. The most common type, neurofibromatosis 1, is characterized by > or = 6 café-au-lait spots and the occurrence of neurofibromas, which may present as cutaneous, subcutaneous or plexiform lesions. Normally, excision of neurofibromas is only indicated in the presence of neurological symptoms, suspicion of malignancy or for exceptional cosmetic reasons. For a good functional and aesthetic result with the least danger of recurrence, the surgeon's goal is to excise as much tissue as necessary and as little tissue as possible. One of the main issues during the surgical procedure is to distinguish between neurofibroma and surrounding tissue. We report for the first time the use of confocal laser scanning microscopy to differentiate between neurofibroma and healthy skin.

Reflectance confocal microscopy of facial lentigo maligna and lentigo maligna melanoma: a preliminary study

BACKGROUND

Facial lentigo maligna (LM) and lentigo maligna melanoma (LMM) may be difficult to diagnose clinically and dermoscopically. Reflectance confocal microscopy (RCM) enables the in vivo assessment of equivocal skin lesions at a cellular level.

OBJECTIVES

To assess cytomorphological and architectural RCM features of facial LM/LMM.

METHODS

Four women and eight men aged 58-88 years presenting with facial skin lesions suspicious of LM/LMM were included. In total, 17 lesion areas were imaged by RCM before biopsy. The histopathological diagnosis of LM was made in 15 areas; the other two were diagnosed as early LMM.

RESULTS

A focal increase of atypical melanocytes and nests surrounding adnexal openings, sheets of mainly dendritic melanocytes, cord-like rete ridges at the dermoepidermal junction (DEJ) and an infiltration of adnexal structures by atypical melanocytes were found to be characteristic RCM features of facial LM/LMM. Areas with a focal increase of atypical melanocytes and nests surrounding adnexal openings were observed at the basal layer in three cases. The remaining cases displayed these changes at suprabasal layers above sheets of mainly dendritic melanocytes. Cord-like rete ridges at the DEJ and an infiltration of adnexal structures by atypical melanocytes were observed in all cases. Previously described criteria for RCM diagnosis of melanoma, such as epidermal disarray, pleomorphism of melanocytes and pagetoid spreading of atypical melanocytes, were additionally observed.

CONCLUSIONS

We observed a reproducible set of RCM criteria in this case series of facial LM/LMM.

In vivo confocal laser scanning microscopy of melanocytic skin tumours: diagnostic applicability using unselected tumour images

BACKGROUND

In vivo confocal laser scanning microscopy (CLSM) represents a novel imaging tool that allows the noninvasive examination of skin cancer morphology in real time at a 'quasi-histopathological' resolution viewing microanatomical structures and individual cells.

OBJECTIVES

To validate diagnostic confocal examination of melanocytic skin tumours using unselected tumour images.

METHODS

In the present study, we used a total of 3709 unselected CLSM tumour images obtained from 20 malignant melanomas and 50 benign naevi. The entire set of images derived from each tumour was evaluated by independent observers. Classification tree analysis based on a subsample of 857 tumour images was performed to develop a diagnostic algorithm.

RESULTS

Overall, sensitivity and specificity of 97.5% and 99% could be achieved by the independent observers (positive predictive value 97.5%, negative predictive value 99%). Classification tree analysis yielded a three-step algorithm based on only three morphological CLSM features, facilitating a correct classification in 92.4% of the benign naevus images and 97.6% of melanoma images.

CONCLUSIONS

In vivo CLSM augurs a sea change in the way we will view skin tumour processes clinically at the bedside and merits application for use as a screening tool in skin oncology.

The use of confocal laser-scanning microscopy in microsurgery for invasive squamous cell carcinoma

BACKGROUND

Ex-vivo confocal laser-scanning microscopy offers rapid imaging of excised tissue specimens without conventional histotechnical procedures. As vertical sections are prepared, morphological features can be assessed according to standard criteria used in conventional histopathology.

OBJECTIVES

To validate the diagnostic confocal examination of squamous cell carcinoma (SCC) in microscopy-guided surgery.

METHODS

Four independent observers received standardized instructions about diagnostic confocal microscopy features of SCC. Subsequently, 120 confocal images of fresh excisions from SCC or normal skin, imaged using a commercially available, near-infrared, reflectance confocal laser-scanning microscope, were evaluated by each observer.

RESULTS

General morphology, such as location, size and shape of the cancer area could be visualized by the imaging system. Furthermore, densely packed and irregularly organized nuclei and nuclear atypia could be delineated. Overall, a sensitivity of 95% and a specificity of 96.25% were achieved by the four observers (positive predictive value 96.25%, negative predictive value 95.23%).

CONCLUSIONS

This study provides a set of well-described morphological criteria with obvious diagnostic impact which should be used in further investigations. In the future, confocal laser-scanning microscopy may guide microsurgery of any skin cancer.

Adapting the fluoroscope to image-guided surgery

Image-guided techniques have been well established in all surgical disciplines for years. To achieve an optimised work flow during image-guided surgery, the surgeon should be able to manipulate the visual feedback and therefore the imaging unit. C-arm fluoroscopy is the imaging modality routinely used for intraoperative imaging in orthopaedic surgery. The C-arm fluoroscope is positioned and handled by a radiographer on vocal commands, which means that the surgeon depends on external help to manipulate the visual feedback and the work flow is not optimised. The MEPUC interface adapts the C-arm fluoroscope to the needs of image-guided orthopaedic procedures. MEPUC is an acronym for Motorised Exact-Positioning Unit for C-arm. In the hardware component of the MEPUC a conventional C-arm fluoroscope is equipped with stepping motors. The software component allows the surgeon to control the motorised movements of the fluoroscope. The MEPUC interface enables the surgeon to position the C-arm fluoroscope independently in the operating room. Further advantages are achievable when the MEPUC interface is combined with surgical navigation, as this combination allows fully automatic reproduction of former projections. Clinical experience with the MEPUC interface suggests that the work flow for intraoperative imaging is improved and personal requirements reduced.

Brazilian adolescents' prosocial moral judgment and behavior: relations to sympathy, perspective taking, gender-role orientation, and demographic characteristics

The goal of this study was to examine demographic and individual difference variables that predict level of prosocial moral judgment and self-reported prosocial behavior and to test mediating or moderating relations among predictors. The relations of prosocial moral reasoning and self-reported prosocial behavior to perspective taking, sympathy, age, sociometric status, and gender-role orientation were examined with a sample of 149 Brazilian adolescents who completed a series of questionnaire measures. Prosocial moral judgment was expected to be predicted by both sympathy and perspective taking, whereas sympathy or prosocial moral judgment was expected to mediate the relations of femininity and perspective taking to prosocial behavior. Self-reported perspective taking and sympathy interacted when predicting prosocial moral judgment; adolescents who were high in either sympathy or perspective taking (or both) scored high in prosocial moral reasoning. A feminine orientation predicted sympathy and perspective taking, perspective taking predicted prosocial moral reasoning and sympathy, and sympathy had both direct and indirect paths (through moral judgment) to prosocial behavior. The findings generally were consistent with the contention that both the tendency to take others' perspectives and to sympathize are related to level of prosocial moral reasoning, which in turn motivates prosocial behavior. Moreover, patterns of correlations among variables were similar to those found in the United States.

Primary Bartholin gland carcinoma: a report of seven cases

This study reviews our experience with 7 patients with primary Bartholin gland cancer (BGC) treated at the Queensland Gynaecological Cancer Centre (QCGC) and compares this with previously published data. A retrospective clinicopathologic review of all patients with primary BGC treated at QCGC from 1988 to 2000 was performed. Of the 7 patients treated, all underwent primary surgery and 5 of the 7 patients received radiotherapy postoperatively. All patients presented with a local swelling or a lump. Two had associated discharge and 2 had associated pain. Of the 7 patients, 2, 3 and 2 respectively were classified as having Stage IB, II or III disease. Five of the 7 patients had squamous cell carcinoma (SCC), one had adenoid-cystic carcinoma and 1 had a small-cell neuroendocrine cancer of the Bartholin gland. None of the patients with SCC developed recurrent disease. The patient with adenoid-cystic carcinoma experienced local recurrences at 4 years and again at 5 years and 3 months. Nine years after primary treatment she was diagnosed with pulmonary metastases. The patient with small-cell neuroendocrine cancer of the Bartholin gland was considered tumour-free after operation. Thorough imaging, including a CT scan of her chest, abdomen and pelvis showed no evidence of disease. She died 1 year and three months after diagnosis from disseminated pulmonary disease. We present the first report of small cell neuroendocrine cancer of the Bartholin gland. Therapeutic principles in the management of vulval cancer at other sites appear to be appropriate for management of BGC.

Techniques to improve flow cytometric detection of light chain restriction

OBJECTIVE

To compare 3-color flow cytometry (using a permeabilization step to detect cytoplasmic immunoglobulin in selected cases) with 2-color flow cytometry in the detection of light chain restriction (LCR).

DESIGN

Analysis of clinical specimens submitted for lymphocyte immunophenotyping using both methods.

SETTING

Marshfield Laboratories serving Saint Joseph's Hospital (525 beds) and the Marshfield Health Care Network.

MAIN OUTCOME MEASURE(S)

Sensitivity and specificity for detecting LCR in B-cell neoplasms. Final diagnosis based on review of clinical, laboratory and histologic data.

RESULTS

Of 61 specimens, the 3-color method yielded better sensitivity, detecting LCR in 30 of 39 cases of B-cell neoplasms (77%) versus 16 of 39 (41%) for the 2-color method (P < 0.001). Both methods had comparable specificity (95-100%). The 3-color cytoplasmic technique identified another 4 cases yielding an overall sensitivity of 87% for a 2-tiered testing strategy.

CONCLUSION

A 3-color surface technique, backed up by a permeabilization step in selected cases, provides a cost-effective and sensitive technique for detecting LCR.

[Incidence and development of noticeable hip findings (the dysplasia complex) in newborn and young infants. Additional statistical analysis of the findings]

Early signs of hip dysplasia in 7120 children (in the neonatal period asymmetry of the gluteal folds, Ortolani snap phenomenon and restricted abduction; subsequently, at about 6 weeks, asymmetry of the gluteal folds and restricted abduction) were statistically analyzed with regard to simultaneous occurrence and their prognostic value in confirming a hip dysplasia. The findings at 6 weeks were found to be more serious. Almost no significance can be attached to an isolated finding in the period following birth. Since the study covered several clinics, it was possible to compare findings from individual centers. It was found that they fell into four groups with different diagnostic preferences, despite the agreed uniform examination technique. Thus, almost all of the positive Ortolani findings were diagnosed at two of the 20 clinics taking part in the study. In the overall comparison the group of clinics which relied almost exclusively on asymmetry of the gluteal folds had the least prognostic success. The clinics with a higher proportion of positive Ortolani findings had better prognosis results, though the incidence of dysplasias was not increased.

Prospective study of suspected associations between certain drugs administered during early pregnancy and congenital malformations

From 1964 to 1976, a cohort study was performed in West Germany to study the possible influence of various factors on pregnancy and child development. Results of the evaluation of 13,643 pregnancies are given with respect to possible teratogenetic effects of antiemetic drugs and sex hormones administered in early pregnancy. There was no evidence of an increased risk of major malformations following the intake of certain antiemetic drugs and progesterone. Also, the use of a hormonal pregnancy test was not significantly associated with an increase of major malformations.

[Chances of abortion prophylaxis in early pregnancy (author's transl)]

7870 pregnancies during the years 1964-1970 observed in a cooperative clinical study give the data basis of an exploratory statistical analysis. Here the associations of drugs taken during the first three months of pregnancy with the incidence of early spontaneous abortions before the fifth month are demonstrated. The rates are corrected for time of enrollment. Women having taken antiemetic drugs or preparations containing vitamins or minerals have less abortions than women without intake of these drugs. This is found especially in the presence of early nausea or vomiting and of bleedings in the first trimenon. It is important that these drugs have not been used for the treatment of bleedings. Therefore the takers and the non-takers are comparable. A success of the then usual treatment with female sexual hormones could not be found. The high abortion rates of women treated with tranquilizers cannot be interpreted as a failure of this treatment because of the epidemiological non-experimental character of the study.