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European Journal of Dentistry 2015This article reviews the diagnosis and treatment of cracked teeth, and explores common clinical examples of cracked teeth, such as cusp fractures, fractures into tooth... (Review)
Review
This article reviews the diagnosis and treatment of cracked teeth, and explores common clinical examples of cracked teeth, such as cusp fractures, fractures into tooth furcations, and root fractures. This article provides alternative definitions of terms such as cracked teeth, complete and incomplete fractures and crack lines, and explores the scientific rationale for dental terminology commonly used to describe cracked teeth, such as cracked tooth syndrome, structural versus nonstructural cracks, and vertical, horizontal, and oblique fractures. The article explains the advantages of high magnification loupes (×6-8 or greater), or the surgical operating microscope, combined with co-axial or head-mounted illumination, when observing teeth for microscopic crack lines or enamel craze lines. The article explores what biomechanical factors help to facilitate the development of cracks in teeth, and under what circumstances a full coverage crown may be indicated for preventing further propagation of a fracture plane. Articles on cracked tooth phenomena were located via a PubMed search using a variety of keywords, and via selective hand-searching of citations contained within located articles.
PubMed: 26038667
DOI: 10.4103/1305-7456.156840 -
Proceedings of the National Academy of... Dec 2020Microscopic evaluation of resected tissue plays a central role in the surgical management of cancer. Because optical microscopes have a limited depth-of-field (DOF),...
Microscopic evaluation of resected tissue plays a central role in the surgical management of cancer. Because optical microscopes have a limited depth-of-field (DOF), resected tissue is either frozen or preserved with chemical fixatives, sliced into thin sections placed on microscope slides, stained, and imaged to determine whether surgical margins are free of tumor cells-a costly and time- and labor-intensive procedure. Here, we introduce a deep-learning extended DOF (DeepDOF) microscope to quickly image large areas of freshly resected tissue to provide histologic-quality images of surgical margins without physical sectioning. The DeepDOF microscope consists of a conventional fluorescence microscope with the simple addition of an inexpensive (less than $10) phase mask inserted in the pupil plane to encode the light field and enhance the depth-invariance of the point-spread function. When used with a jointly optimized image-reconstruction algorithm, diffraction-limited optical performance to resolve subcellular features can be maintained while significantly extending the DOF (200 µm). Data from resected oral surgical specimens show that the DeepDOF microscope can consistently visualize nuclear morphology and other important diagnostic features across highly irregular resected tissue surfaces without serial refocusing. With the capability to quickly scan intact samples with subcellular detail, the DeepDOF microscope can improve tissue sampling during intraoperative tumor-margin assessment, while offering an affordable tool to provide histological information from resected tissue specimens in resource-limited settings.
Topics: Algorithms; Animals; Biopsy; Calibration; Carcinoma; Deep Learning; Humans; Image Processing, Computer-Assisted; Microscopy, Fluorescence; Mouth Neoplasms; Swine
PubMed: 33318169
DOI: 10.1073/pnas.2013571117 -
Biomedical Optics Express Nov 2018By integrating a phase-only Spatial Light Modulator (SLM) into the illumination arm of a cylindrical-lens-based Selective Plane Illumination Microscope (SPIM), we have...
By integrating a phase-only Spatial Light Modulator (SLM) into the illumination arm of a cylindrical-lens-based Selective Plane Illumination Microscope (SPIM), we have created a versatile system able to deliver high quality images by operating in a wide variety of different imaging modalities. When placed in a Fourier plane, the SLM permits modulation of the microscope's light-sheet to implement imaging techniques such as structured illumination, tiling, pivoting, autofocusing and pencil beam scanning. Previous publications on dedicated microscope setups have shown how these techniques can deliver improved image quality by rejecting out-of-focus light (structured illumination and pencil beam scanning), reducing shadowing (light-sheet pivoting), and obtaining a more uniform illumination by moving the highest-resolution region of the light-sheet across the imaging Field of View (tiling). Our SLM-SPIM configuration is easy to build and use, and has been designed to allow all of these techniques to be employed on an easily reconfigurable optical setup, compatible with the OpenSPIM design. It offers the possibility to choose between three different light-sheets, in thickness and height, which can be selected according to the characteristics of the sample and the imaging technique to be applied. We demonstrate the flexibility and performance of the system with results obtained by applying a variety of different imaging techniques on samples of fluorescent beads, zebrafish embryos, and optically cleared whole mouse brain samples. Thus our approach allows easy implementation of advanced imaging techniques while retaining the simplicity of a cylindrical-lens-based light-sheet microscope.
PubMed: 30460137
DOI: 10.1364/BOE.9.005419 -
Indian Journal of Otolaryngology and... Oct 2022To assess the parameters' setting of the microscope during parotidectomy and the impact of microscopic parotidectomy on facial nerve functional status. A prospective...
To assess the parameters' setting of the microscope during parotidectomy and the impact of microscopic parotidectomy on facial nerve functional status. A prospective study was conducted on 28 patients in a tertiary care center, who underwent microscopic parotidectomy. Microscope's settings' like magnification, focal length, diameter of the visualized field, and clock position were recorded. Facial nerve functional status was also recorded. All surgeries were performed by right-handed surgeons using Leica F 20 M525 microscope. Clock position of microscope for right parotidectomy ranged between 7 and 10 o clock and for left, it ranged between 7 and 12 o clock. Magnification ranged between 1.3 × and 3.2 ×; magnifications of 1.3 × and 1.8 × were preferred from incision to separation of parotid from sternocleidomastoid muscle, 1.8 × and 2 × for dissection of the facial nerve trunk, and 2 × and 3.2 × for individual branches of the facial nerve. Focal length ranged between 251 and 410 mm and the diameter of the visualized field ranged between 7 and 14.7 cm. Out of 24 cases of benign lesions, 2 (8.3%) developed facial paresis which resolved in 3 months. Two out of four cases of malignancy developed permanent palsy as nerve branches were sacrificed to achieve tumor clearance. Using a microscope for parotidectomy is advantageous for facial nerve dissection, reducing chances of facial paralysis. The microscope was also found to be useful for teaching. The use of appropriate microscopic parameters avoids the glitch of transition from open to microscopic approach.
PubMed: 36452574
DOI: 10.1007/s12070-020-02106-2 -
Cells Nov 2022In bio-medical mobile workstations, e.g., the prevention of epidemic viruses/bacteria, outdoor field medical treatment and bio-chemical pollution monitoring, the... (Review)
Review
In bio-medical mobile workstations, e.g., the prevention of epidemic viruses/bacteria, outdoor field medical treatment and bio-chemical pollution monitoring, the conventional bench-top microscopic imaging equipment is limited. The comprehensive multi-mode (bright/dark field imaging, fluorescence excitation imaging, polarized light imaging, and differential interference microscopy imaging, etc.) biomedical microscopy imaging systems are generally large in size and expensive. They also require professional operation, which means high labor-cost, money-cost and time-cost. These characteristics prevent them from being applied in bio-medical mobile workstations. The bio-medical mobile workstations need microscopy systems which are inexpensive and able to handle fast, timely and large-scale deployment. The development of lightweight, low-cost and portable microscopic imaging devices can meet these demands. Presently, for the increasing needs of point-of-care-test and tele-diagnosis, high-performance computational portable microscopes are widely developed. Bluetooth modules, WLAN modules and 3G/4G/5G modules generally feature very small sizes and low prices. And industrial imaging lens, microscopy objective lens, and CMOS/CCD photoelectric image sensors are also available in small sizes and at low prices. Here we review and discuss these typical computational, portable and low-cost microscopes by refined specifications and schematics, from the aspect of optics, electronic, algorithms principle and typical bio-medical applications.
Topics: Microscopy; Point-of-Care Systems; Lenses; Algorithms; Microscopy, Interference
PubMed: 36429102
DOI: 10.3390/cells11223670 -
Wellcome Open Research 2021We have developed "Microscope-Cockpit" (Cockpit), a highly adaptable open source user-friendly Python-based Graphical User Interface (GUI) environment for precision...
We have developed "Microscope-Cockpit" (Cockpit), a highly adaptable open source user-friendly Python-based Graphical User Interface (GUI) environment for precision control of both simple and elaborate bespoke microscope systems. The user environment allows next-generation near instantaneous navigation of the entire slide landscape for efficient selection of specimens of interest and automated acquisition without the use of eyepieces. Cockpit uses "Python-Microscope" (Microscope) for high-performance coordinated control of a wide range of hardware devices using open source software. Microscope also controls complex hardware devices such as deformable mirrors for aberration correction and spatial light modulators for structured illumination via abstracted device models. We demonstrate the advantages of the Cockpit platform using several bespoke microscopes, including a simple widefield system and a complex system with adaptive optics and structured illumination. A key strength of Cockpit is its use of Python, which means that any microscope built with Cockpit is ready for future customisation by simply adding new libraries, for example machine learning algorithms to enable automated microscopy decision making while imaging.
PubMed: 37283605
DOI: 10.12688/wellcomeopenres.16610.1 -
Journal of Biomedical Optics Jan 2021Surgical microscopes provide adjustable magnification, bright illumination, and clear visualization of the surgical field and have been increasingly used in operating... (Review)
Review
SIGNIFICANCE
Surgical microscopes provide adjustable magnification, bright illumination, and clear visualization of the surgical field and have been increasingly used in operating rooms. State-of-the-art surgical microscopes are integrated with various imaging modalities, such as optical coherence tomography (OCT), fluorescence imaging, and augmented reality (AR) for image-guided surgery.
AIM
This comprehensive review is based on the literature of over 500 papers that cover the technology development and applications of surgical microscopy over the past century. The aim of this review is threefold: (i) providing a comprehensive technical overview of surgical microscopes, (ii) providing critical references for microscope selection and system development, and (iii) providing an overview of various medical applications.
APPROACH
More than 500 references were collected and reviewed. A timeline of important milestones during the evolution of surgical microscope is provided in this study. An in-depth technical overview of the optical system, mechanical system, illumination, visualization, and integration with advanced imaging modalities is provided. Various medical applications of surgical microscopes in neurosurgery and spine surgery, ophthalmic surgery, ear-nose-throat (ENT) surgery, endodontics, and plastic and reconstructive surgery are described.
RESULTS
Surgical microscopy has been significantly advanced in the technical aspects of high-end optics, bright and shadow-free illumination, stable and flexible mechanical design, and versatile visualization. New imaging modalities, such as hyperspectral imaging, OCT, fluorescence imaging, photoacoustic microscopy, and laser speckle contrast imaging, are being integrated with surgical microscopes. Advanced visualization and AR are being added to surgical microscopes as new features that are changing clinical practices in the operating room.
CONCLUSIONS
The combination of new imaging technologies and surgical microscopy will enable surgeons to perform challenging procedures and improve surgical outcomes. With advanced visualization and improved ergonomics, the surgical microscope has become a powerful tool in neurosurgery, spinal, ENT, ophthalmic, plastic and reconstructive surgeries.
Topics: Industrial Development; Microscopy; Neurosurgical Procedures; Surgery, Computer-Assisted; Tomography, Optical Coherence
PubMed: 33398948
DOI: 10.1117/1.JBO.26.1.010901 -
Biophysical Reports Sep 2021One of the most widely used microscopy techniques in biology and medicine is fluorescence microscopy, offering high specificity in labeling as well as maximal... (Review)
Review
One of the most widely used microscopy techniques in biology and medicine is fluorescence microscopy, offering high specificity in labeling as well as maximal sensitivity. For live-cell imaging, the ideal fluorescence microscope should offer high spatial resolution, fast image acquisition, three-dimensional sectioning, and multicolor detection. However, most existing fluorescence microscopes have to compromise between these different requirements. Here, we present a multiplane, multicolor wide-field microscope that uses a dedicated beam splitter for recording volumetric data in eight focal planes and for three emission colors with frame rates of hundreds of volumes per second. We demonstrate the efficiency and performance of our system by three-dimensional imaging of multiply labeled fixed and living cells. The use of commercially available components makes our proposed microscope straightforward for implementation, thus promising for widely used applications.
PubMed: 36425311
DOI: 10.1016/j.bpr.2021.100001 -
Journal of Microscopy and Ultrastructure 2022Smartphones can be used to capture images from the microscope. There are commercial and homemade adapters that can be used to overcome the difficulty of focusing on a...
BACKGROUND AND AIM
Smartphones can be used to capture images from the microscope. There are commercial and homemade adapters that can be used to overcome the difficulty of focusing on a smartphone camera. We conducted this study to test if the usage of a homemade adapter reduces the time and effort of the operator in comparison to the free-hand technique in smartphone photomicrography.
MATERIALS AND METHODS
We made a simple smartphone adapter for digital photomicrography. Thirty-two operators first captured the image on the smartphone with the free-hand technique and then with the adapter thrice from a microscope. The time for focusing was compared statistically by paired -test. A survey was conducted to know operators's opinions on adapter-assisted photomicrography.
RESULT
All the participants were able to capture images from the microscopes. The average time for focusing with adapter was (11.89 ± 4.19 seconds) significantly ( = 0.0001) lower than the free-hand technique (25.56±11.81 seconds). However, the images yielded from both techniques were of equal quality. The majority of the participant found the method to be easy and reduce their effort in focusing and capturing an image.
CONCLUSION
Low-cost homemade smartphone adapter helps in reducing the time required for capturing an image from the microscope. It decreases the effort of the operator in comparison to the free-hand technique. Hence, it may be a good choice for those who need to capture images from the microscopes frequently for either telemedicine or research purpose in resource-limited settings.
PubMed: 35433256
DOI: 10.4103/JMAU.JMAU_45_20