Preliminary study of video imaging of blood vessels in tissues lining the gingival sulcus in periodontally healthy individuals.

BACKGROUND AND OBJECTIVE: The aim of this study was to obtain in vivo images of the microcirculation in tissues lining the gingival crevice in periodontally healthy volunteers and to assess the repeatability of the parameters measured. MATERIAL AND METHODS: Video microscopy images of the microcirculation of tissues lining the gingival crevice were obtained from 20 periodontally healthy volunteers. Images were obtained with a single 1 mm diameter 1 pitch gradient index lens with a high numerical aperture and with a plain glass lens and illumination with a green 525 nm light-emitting diode and recorded using a video microscope. RESULTS: The morphological features of the vessels (including vessel diameter, vessel density, loops, branches, dilated vessels) were similar to those described previously in other mammals. The Kappa values for the assessment of morphology of the vessels using the gradient index lens range from 0.83 for branching to 0.91 for dilated and using the glass lens 0.47 for branching and 0.38 for dilated. CONCLUSIONS: This novel system allowed for a consistent and repeatable assessment of the gingival microvasculature. However, there was some evidence of possible pressure artefacts in those cases where the measurements of separation between vessels exceeded 150 µm.

Enhancing your practice with the magnifying video scope.

The MVS (such as the Explorer and the MagnaVu) allows the dentist and team to provide quality dentistry in a more comfortable position, for longer periods of time. This is especially important for complex surgical and extensive restorative/aesthetic cases. The procedures that would be enhanced via the MVS include: diagnostic, preventative care, restorative, periodontal, endodontic, orthodontic, implant, and laser dentistry.

Combined effects of microtopography and cyclic strain on vascular smooth muscle cell orientation.

Cellular alignment studies have shown that cell orientation has a large effect on the expression and behavior of cells. Cyclic strain and substrate microtopography have each been shown to regulate cellular alignment. This study examined the combined effects of these two stimuli on the alignment of bovine vascular smooth muscle cells (VSMCs). Cells were cultured on substrates with microgrooves of varying widths oriented either parallel or perpendicular to the direction of an applied cyclic tensile strain. We found that microgrooves oriented parallel to the direction of the applied strain limited the orientation response of VSMCs to the mechanical stimulus, while grooves perpendicular to the applied strain enhanced cellular alignment. Further, the extent to which parallel grooves limited cell alignment was found to be dependent on the groove width. It was found that for both a small (15microm) and a large (70microm) groove width, cells were better able to reorient in response to the applied strain than for an intermediate groove width (40microm). This study indicates that microtopographical cues modulate the orientation response of VSMCs to cyclic strain. The results suggest that there is a range of microgroove dimensions that is most effective at maintaining the orientation of the cells in the presence of an opposing stimulus induced by cyclic strain.

Burning mouth syndrome: an evaluation of in vivo microcirculation.

BACKGROUND: Burning mouth syndrome (BMS) is an atypical orofacial algesic syndrome. The aim of the authors' research was to investigate the morphological characteristics of peripheral blood circulation in patients with BMS in comparison with those of the peripheral blood circulation in healthy people. METHODS: The authors examined 28 subjects, of whom 14 (10 women and four men) had BMS and 14 (nine women and five men) were healthy control subjects. They performed videocapillaroscopic examination with a capillaroscope with a fiber-optic probe at a magnification of x200, which allowed them to examine the morphological characteristics within the capillaroscopic area accurately. RESULTS: The capillaroscopic examination provided important diagnostic results regarding alterations of the local microcirculation in subjects with BMS when compared with healthy subjects. The results also showed a statistically significant increase in the diameter of the capillary ansae, afferent ansae and efferent ansae in subjects with BMS compared with subjects in the control group (P = .05). CONCLUSION AND CLINICAL IMPLICATIONS: The results revealed a vascular involvement in BMS. This information could improve the understanding of etiopathogenetic factors and aid in the development of therapeutic strategies for treating this disorder.

Operating videoscope for microlaryngeal surgery.

For operative laryngoscopy, a laryngoscope is introduced into the anesthetized patient's mouth for exploration of the larynx and vocal cords. To improve the vision, a binocular microscope is positioned between the operator and the laryngoscope. This interferes, to some degree, with the introduction of instruments, particularly if the surgeon is using bimanual manipulation. In the case of lengthy operations, a fatigue or stress factor can be troublesome to the operator. The authors developed a video laryngoscope using standard blades. An angulated telescope attached to a TV camera was introduced in the top portion of the blade. An enlarged image from the anatomy was produced and viewed from a convenient distance. The manipulations are unobstructed, and simultaneous records can be obtained. It is the method of choice for teaching. The operative laryngoscope is less cumbersome and supersedes the microscope for viewing the endolarynx. This new technique was used successfully in 532 cases.

Fast algorithm for real-time detection of root canal orifices in video images.

Real-time image analysis in endodontics opens new options of treatment support in dentistry. Imaging software was developed to detect the root canal orifices in video sequences of trepanated teeth acquired by a digital video microscope, the Motic DM 143. The software developed is capable of communicating with any video camera connected to it and can automatically detect almost all root canal orifices in trepanated teeth. To recognize the root canal orifices we used the so-called Minimum-Distance Classification. The Minimum-Distance Classification provides a color-based pattern recognition algorithm, which is directly implemented in the function accessing the video stream, and is therefore very fast. Processing speed varied between 30 and 64 ms per image with an input image resolution of 352 x 288 pixels on the Pentium 4 computer (2 GHz). The developed software was tested in this study on 78 trepanated teeth. The mean detection sensitivity of the software found for all 78 teeth is 97.01%.

Rapid palatal expansion: the role of microcirculation.

AIM: Transverse palate modifications fall under expansive orthopedic therapy of the upper maxilla. The only practical approach to the problem on the transverse plane is that of performing the expansion of the maxillary arch through an opening of the median palatal suture. It is important to understand the changes of the vascular network in midpalatal suture following the starting of rapid maxillary expansion. It is critical to maintain the blood supply and circulation for the osteogenesis and bone remodeling after the expansion. The aim of this research was to evaluate the effects of rapid orthopedic expansion (REP) at the microcirculatory level through capillaroscopic examination. METHODS: Fifteen patients in their developing years between 9 and 15 years of age (average age 12.16 years) were examined. The application of the REP was the first step in the planning of orthopedic-orthodontic treatment which foresaw further stages in the odonto-osseous movement. The method of Biomicroscopic Video-Imaging of the microcirculation of oral mucosa is performed through the technique of computerized capillaroscopy and the related software. RESULTS: From the results it is evident that immediately after achieving the expansion of the upper maxilla (t1), a slight decrease in the number of vessels per mm² can be observed. In addition, a slight ectasia can be observed in these vessels in comparison to t0. Comparing the videocapillaroscopic images of t1 and t2, an increase in the capillaries per mm² can be observed. CONCLUSION: Ectasia of the capillaries, though subject to strictly individual variables, can be considered perfectly normal and it is compatible with the normal biology and physiology of vessel microcirculation.

The anatomy of the surgical operating microscope and operating positions.

This article explores the current status of magnification and illumination in endodontic surgery. The basic operations of the operating microscope are described in detail and common misconceptions regarding its operation are explained. Finally, the various operating positions used in endodontic microsurgery are described and illustrated.

Lipid vesicle shape analysis from populations using light video microscopy and computer vision.

We present a method for giant lipid vesicle shape analysis that combines manually guided large-scale video microscopy and computer vision algorithms to enable analyzing vesicle populations. The method retains the benefits of light microscopy and enables non-destructive analysis of vesicles from suspensions containing up to several thousands of lipid vesicles (1-50 µm in diameter). For each sample, image analysis was employed to extract data on vesicle quantity and size distributions of their projected diameters and isoperimetric quotients (measure of contour roundness). This process enables a comparison of samples from the same population over time, or the comparison of a treated population to a control. Although vesicles in suspensions are heterogeneous in sizes and shapes and have distinctively non-homogeneous distribution throughout the suspension, this method allows for the capture and analysis of repeatable vesicle samples that are representative of the population inspected.

Seeing through the dentist's eyes: video-based clinical demonstrations in preclinical dental training.

The clinical demonstration is an established way of bridging the disciplinary content in preclinical and clinical courses. In dentistry, however, clinical demonstrations have often been perceived as less rewarding due to the restricted visual access to the details of the treatment. This study investigated a course in endodontics at the University of Gothenburg, Sweden, in which traditional clinical demonstrations were replaced by instructor-led seminars that enabled students to follow and discuss broadcasted root canal treatments. Two cameras provided overviews of the operating room, whereas a third camera attached to a surgical microscope offered a magnified view of procedures carried out in the inner parts of teeth. The hypothesis was that this arrangement would increase the students' sense of the clinical relevance of basic scientific knowledge. Two focus group interviews were designed to explore the students' perceptions of this change. The students expressed that the video-based seminars offered ample opportunities to integrate theoretical and clinical understanding. The major reasons were that the visualization displayed procedures on a sufficiently detailed level; instructors demonstrated clinical reasoning in situ and provided the context necessary for understanding procedures; and the interactive format encouraged discussions on the generalizability of knowledge beyond the specific case.

Resin-packed nanoelectrospray in combination with video and mass spectrometry for the direct and real-time molecular analysis of mast cells.

A nano-electrospray ionization (nanoESI) emitter for analysis of a biological solution was developed by packing a nanoESI needle with two types of resins for desalting and preconcentration of target molecules. Determination of secreted histamine and serotonin molecules in cell culture buffers was demonstrated using 5-methyltryptamine as internal standard. The results showed good linearity of target signals in the concentration range from 0.25 to 50.0 ng/mL of histamine or serotonin. These molecules were monitored to be secreted by A23187 (calcium ionophore) stimulant in rat peritoneal mast cells. Using a combination of a video-microscope and a mass spectrometer, we could visualize exocytotic moments and analyze secreted molecules by mass spectrometry simultaneously. Time-dependent release of histamine and serotonin from activated mast cells showed that significant production of these molecules occurred and reached a maximal level at 15 min for serotonin and at 30 min for histamine, respectively. These results showed that this method allows the direct and timely analysis of secreted molecules in biological responses.

A dental vision system for accurate 3D tooth modeling.

This paper describes an active vision system based reverse engineering approach to extract the three-dimensional (3D) geometric information from dental teeth and transfer this information into Computer-Aided Design/Computer-Aided Manufacture (CAD/CAM) systems to improve the accuracy of 3D teeth models and at the same time improve the quality of the construction units to help patient care. The vision system involves the development of a dental vision rig, edge detection, boundary tracing and fast & accurate 3D modeling from a sequence of sliced silhouettes of physical models. The rig is designed using engineering design methods such as a concept selection matrix and weighted objectives evaluation chart. Reconstruction results and accuracy evaluation are presented on digitizing different teeth models.

In vivo visualization of oxygen transport in microvascular network.

Oxygen transport from the blood to the tissues is a diffusive process driven by the gradient of oxygen tension (PO2). We developed an oxygen-quenching fluorescent membrane that allowed visualization of the PO2 distribution near the microvessels as optical patterns on the membrane by epifluorescence microscopy. This membrane was highly gas permeable to allow PO2 measurement and was transparent enough to also permit observation of the microcirculation. In combination with a newly devised gastight chamber and a micropositioning system, this membrane technique made it possible to visualize the PO2 distribution in the rat mesenteric microvascular network under well-defined conditions. Our preliminary findings indicate that the oxygen distribution in the microvascular network is heterogeneous and suggest that there is considerable release of oxygen from the arterioles. The time lag of the system for tracking rapid PO2 changes in vitro was shown to be negligible, indicating that dynamic PO2 changes occurring in vivo can also be assessed. This technique should provide a novel tool for the study of oxygen transport and metabolism under normal and abnormal conditions.

Microfluidic ELISA: on-chip fluorescence imaging.

Fluorescent reactions of a heterogeneous sandwich enzyme-linked immunoassay (ELISA) in an all-PDMS [poly (dimethylsiloxane)] microfluidic device were detected using a cooled charge coupled device (CCD) camera interfaced with an epifluorescence microscope. The study represents preliminary efforts to integrate biochemical reactions and detection on-chip using the "hybrid" detection approach. In initial experiments, the PDMS chip microsensor was successfully used to quantify a model analyte (sheep IgM) with sensitivity down to 17nM. Thus, we demonstrate here the extension of this hybrid integrated technique to on-chip imaging and quantification of light emission from a biochemical immunoassay in PDMS chip.

Study of platelet behavior in vivo after endothelial stimulation with laser irradiation using fluorescence intravital videomicroscopy and PEGylated liposome staining.

Platelets contain an array of potent proinflammatory mediators, and therefore they are regarded as mediator and effector cells in inflammation. Knowing the role of platelets during these processes is crucial and the analysis of their behavior in situ and the associated mechanisms is consequently particularly important. However, conventional in vitro staining techniques induce modification of the characteristics of platelets. This study aimed to evaluate platelet behavior in vivo after endothelial stimulation (without endothelial denudation or exposure of basal lamina and/or collagen) with an argon laser, using video intravital microscopy in combination with a new an innovative platelet staining technique based on polyethyleneglycol (PEG) liposomes. The study was performed on skin by using a dorsal skin-fold chamber implanted in golden hamsters. Platelets were stained by 5,6-CF-encapsulated PEGylated liposomes injected intravenously. The skin microcirculation was observed with an intravital microscope (using x25, x40, and x80 magnifications) fitted with a xenon light source, an epifluorescence assembly, and an ultra-high sensitivity video camera for fluorescence imaging. Platelet activation without endothelial denudation or exposure of basal lamina and/or collagen was obtained with an argon laser emitting at 514.5 nm with the following parameters: 20 mW, 300 ms, 120 J/cm(2). The 80-microm laser beam was focused on a vessel and its position was controlled with the microscope. Thanks to the spatial resolution of the intravital microscopic imaging system, the platelets were seen rolling individually on the endothelium. After laser stimulation, platelets were activated and three phases were observed: recruitment, adhesion and detachment. The observation of these three phases was time dependent and the kinetics of the process were quantified. The recruitment reached a maximum after 90 +/- 20 s. The adhesion phase lasted for 110 +/- 25 s. At last, detachment of all platelets was observed. This detachment started 200 +/- 20 s after irradiation and was completed in less than 2 min. This study confirms that laser irradiation used with optimal parameters can induce platelet activation without thrombus formation. Platelets can adhere only transiently on stimulated endothelium. This phenomenon may therefore represent a defense mechanism, by which platelets would accumulate in the vicinity of an injury, making them available for immediate response. At last, this study has clearly demonstrated the advantages of our new and innovative platelet staining method using PEGylated liposomes, which are (i) in situ labeling, (ii) use of a hydrophilic marker located in an aqueous compartment within the platelet, and (iii) labeling of platelets allowing observation during the whole experiment.

Study of the microcirculation of oral mucosa in healthy subjects.

The research has the following aims: 1: to verify the applicability of capillaroscopic investigation to oral mucosa; 2: to propose oral mucosa as an alternative to the fingernail fold for capillaroscopic investigation; 3: to describe the characteristics of the microcirculation of oral mucosa in healthy subjects. 100 healthy patients were examined. The characteristics of the micro-circulation in the areas of gum mucosa and the mucosa covering of the lower lip were examined using computerised videomicroscopic techniques. For each patient we evaluated the visibility, the course, the density, the tortuosity and any images characteristic of capillary loops, besides the possible presence of microhaemorrhages, the average calibre of capillary loops and the number of capillary loops visible per square millimetre. The investigation was simple, non invasive and repeatable for each patient. An investigation of gum mucosa has revealed a course of capillary loops both parallel and perpendicular to the surface: often the tops of the capillary loops appear as regularly distributed dots or commas. Microcirculatory architecture in the area of the mucosa covering is characterised by capillary loops with a variable diameter, course and length; next to typical capillary loops with the appearance of horse stirrups, there are other loops similar to hairpins, commas and cork screws; there are also rare microhaemorrhages with the aspect of reddish stains, that could be caused by microtraumas. Visibility was very good in the area of the mucosa covering of the lower lip: mediocre in the area of gum mucosa. Our research has highlighted, that today it is possible to carry out a capillaroscopic investigation of oral mucosa in a simple and reliable way. Future research could evaluate how "normal microcirculation", that we describe in this paper, is modified during pathology