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• The swept-source optical coherence tomography was utilized to visualize the geometry of dental implants. • The developed boundary flattening algorithm evaluated the surface roughness. • The cross-sections and volume renders revealed various parameters of implant thread geometry. • The depth of thread was clearly measured using a depth-directional intensity profile. • The method demonstrated the applicability for the enhancement of quality and stability after fabrications. The geometrical characteristics of dental implants, such as thread depth and width, facing angle, pitch, and surface roughness, are important to assess their stability and osseointegration after implant surgery. Herein, we demonstrate the potential use of depth-resolved swept-source optical coherence tomography (SS-OCT) to assess the structural quality of widely used dental implants. The implemented SS-OCT system was centered at a wavelength of 1300 nm with a 100 nm full-width at half-maximum. Four dental implants with different structural formations fabricated using either titanium or ceramic were visualized. Qualitative assessments were performed using boundary flattening with an amplitude-profiling algorithm to emphasize and compare the thread depths, surface roughness, and inner structures of the experimental samples. Cross-sectional and volumetric OCT data clearly revealed the depth, width, and pitch of the dental implants, and especially, the quantitative assessment of axial and lateral thread depth unobtainable using conventional inspection methods was successfully conducted. The depth of thread was measured using a depth-directional intensity profile. In conclusion, the high-resolution SS-OCT system could be utilized to improve the quality assurance of dental implant products through multi-plane assessment. [ABSTRACT FROM AUTHOR]

• Whole-body morphological structures of the ant were investigated using PAM. • Flattening post-pr algorithm procedure after shell removal to observe the internal structure of the ant was implemented. • Quantitative analysis for internal organs was non-invasively conducted through A-scan profiling. • The depth-resolved image analysis was performed to closely observe internal organs by applying the image post-processing algorithm. • This study demonstrates the feasibility of PAM for measuring morphological studies in the entomology field. Whole-body image analysis has been extensively applied in the field of entomology to identify differences in insect morphology. Although various conventional imaging techniques have been used for analyzing insect morphology, these often inflict damage on the sample during preparation and limitedly provide superficial information. To overcome the conventional limitations, in this study, we noninvasively observed the morphological structures of the ant Camponotus atrox , from the whole body to specific parts, over a wide scan range using optical-resolution photoacoustic microscopy (PAM). Based on the obtained photoacoustic maximum amplitude projection images, various structures of the ant, including the antenna, compound eyes, coxa, mandibles, mesonotum, propodeum, petiole, sting, and tergite, could be discerned by covering the entire ant body. In addition, we attained the morphological structures in detail by magnifying three specific parts, namely, the compound eyes, head, and thorax. Furthermore, we non-destructively analyzed the internal structure of various organs, such as the compound eyes, social stomach, and hindgut, via depth profiling of cross-sectional images. Finally, by implementing an algorithm, we visualized the depth-resolved en-face images of internal structures according to a constant depth interval. The findings established that the PAM system could identify not only each external morphological feature of the ant visible but also the sublayers of its internal structures. This study demonstrates the feasibility of PAM for contributing to performing morphological studies in entomological research. [ABSTRACT FROM AUTHOR]

• Optical coherence tomography utilization to evaluate the SLA 3D printing quality. • An image processing algorithm was developed for analyzing surface. • Spectrometer using half-order light from the HD grating was utilized. • Optical signal intensity is presented for varying printing temperatute. • Sorface roughness is presented of the 3D-printed samples. The term "additive manufacturing" refers to three-dimensional (3D) printing, a form of instant prototyping, a layered manufacturing technique that has significantly contributed to the healthcare sector. Stereolithography (SLA) is one of the most extensively utilized 3D printing technologies in dentistry which uses an ultraviolet laser along with resin to manufacture prosthetic models. Higher temperatures may cause crystallization in the interior structure and affect the roughness of the 3D denture models. Therefore, it is crucial to assess the surface roughness and inner-structure crystalization of the final product to ensure a defect-free dental prosthesis. In this study, the surface of an SLA-printed 3D denture was evaluated under various thermal conditions using a high-resolution, spectrometer-oriented, spectral domain optical coherence tomography (SD-OCT). A surface analysis algorithm was developed to analyze the inner structure of the 3D model using each pixel, and the average roughness (RA) value was calculated to measure the surface roughness. To improve the image quality, half-order light from the diffraction grating was used to enhance the spectrometer's performance allowing observation of the internal structure. After applying the surface analysis algorithm, the internal crystallization was observed at a depth of ∼ 10 µm below the sample's surface. This study demonstrates the feasibility of the OCT system along with a high-resolution spectrometer to detect structural deformation by determining the crystal structure inside the 3D sample at various printing temperatures. This research shows the potential use of a high-resolution microscopic analysis using OCT to evaluate the SLA 3D printing quality, which can serve as a guideline for future research investigations in evaluating 3D samples non-destructively. virus-transmitting mosquito specimens. [ABSTRACT FROM AUTHOR]

[Display omitted] • Morphological characteristics of the Ixodidae tick were investigated using SD-OCT. • Qualitative assessment was enhanced using the high numerical aperture objective lens. • Various internal organs were identified non-invasively in the acquired OCT images. • Quantitative analysis for specific organs was conducted through A-scan profiling. • This study can be well-utilized as basic morphological data for the Ixodidae tick. Ixodidae tick, also known as a hard tick, is one of the major vectors of various tick-borne diseases. Studying its anatomy is the fundamental approach for diverse acarological studies and the key to understanding tick morphology. However, the conventional methods of observing internal organs rely primarily on dissection, which damages specimens irrecoverably. In this study, we developed an optical coherence tomography (OCT) system to non-invasively investigate the morphological characteristics of the hard tick. Herein, OCT imaging was conducted by the developed spectral-domain OCT (SD-OCT) system with two different objective lenses. The developed system provides an axial resolution (in the air) of 6.2 µm and a maximum lateral resolution of 2.46 µm as an objective lens with a high numerical aperture (NA) and 10× magnification was employed. Using the developed SD-OCT system, internal organs of tick specimens, such as salivary glands, midgut, genital orifice, and ovary, were identified without inflicting damage. The study suggests the feasibility of the optical coherence imaging for the acarological study of the fundamental morphological inspection and for possible future studies, such as verifying the potential morphological differences among virus transmitted hard tick specimens. [ABSTRACT FROM AUTHOR]

• A new integrated system of surgical microscope and optical coherence tomography angiography for intraoperative applications. • Developed system simultaneously provides superficial, morphological, and blood vessel-related functional information. • Multiple information of surgical region are concurrently displayed on the ocular eyepiece by augmented reality. Intraoperative surgical microscopy integrated with optical coherence tomography (OCT) has improved the accuracy and safety of surgeries by providing a visualization of the sub-surface tissue structure. Although intraoperative OCT has resolved the conventional limitations of the surgical microscope, it is still remained to provide additional informative blood vessel-related data that is required to enhance the stability of surgery by minimizing bleeding and tissue damage. In this paper, we developed a virtual intraoperative OCT angiography integrated surgical microscope (VI-OCTA-SM) to simultaneously visualize morphological tissue structure and microvasculature data of the surgical region including tumor margin and blood vessel map. In addition, cross-sectional OCT and OCTA images and a three-dimensional maximum amplitude projection OCTA vascular map are concurrently displayed on the ocular eyepiece by augmented reality. The results of VI-OCTA-SM-based in-vivo imaging of mouse tissue (ear and brain) with different magnifications confirmed the capability of the VI-OCTA-SM to perform microvasculature imaging of small animals with an adjustable lateral resolution and scanning range according to the experimental conditions. Moreover, we successfully conducted melanoma resection as a simulated surgery following the guidance of the VI-OCTA-SM, which verified the applicability of the developed system to the surgical environment. Our proposed VI-OCTA-SM system has promising potential in various intraoperative applications including dermatological, ophthalmological, and neurological surgeries. [ABSTRACT FROM AUTHOR]