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Pores are the microscopic openings in the skin that emit oils and sweat. Pores can appear larger due to acne, sun damage, or increased sebum production, a waxy and oily substance that causes oily skin. Investigating and extracting sebum from facial pores is essential for treating skin issues as the enlargement of the pores causes higher susceptibility of the skin to microbe aggressions and inflammatory reactions. In this study, we assessed the volumetric size of pores before and after the sebum extraction using spectral domain optical coherence tomography (SD-OCT). To properly estimate the volume of the sebum before and after extraction, multiple cross-sectional OCT images were selected. The area of a single pixel was calculated from the OCT images using the scanning range. Furthermore, an algorithm was developed to use the pixel area to calculate the full volumetric size of the skin pore. This research illustrates the use of a high-resolution microscopic analysis using SD-OCT in dermatological research and can operate as a guideline for future research investigations in evaluating non-destructively wounded tissue analysis, underlying skin biochemistry, and facial statistical approaches in skin parameters for moisturizer treatment.

Photoacoustic imaging (PAI) is a hybrid non-invasive imaging technique used to merge high optical contrast and high acoustic resolution in deep tissue. PAI has been extensively developed by utilizing its advantages that include deep imaging depth, high resolution, and label-free imaging. As a representative implementation of PAI, photoacoustic microscopy (PAM) has been used in preclinical and clinical studies for its micron-scale spatial resolution capability with high optical absorption contrast. Several handheld and portable PAM systems have been developed that improve its applicability to several fields, making it versatile. In this study, we developed a laboratory-customized, two-axis, waterproof, galvanometer scanner-based handheld PAM (WP-GVS-HH-PAM), which provides an extended field of view (14.5 × 9 mm2) for wide-range imaging. The fully waterproof handheld probe enables free movement for imaging regardless of sample shape, and volume rate and scanning region are adjustable per experimental conditions. Results of WP-GVS-HH-PAM-based phantom and in vivo imaging of mouse tissues (ear, iris, and brain) confirm the feasibility and applicability of our system as an imaging modality for various biomedical applications.

The aim of this study was to quantitatively assess the residual adhesive on orthodontic ceramic bracket-removed dental surface. In orthodontic process, ceramic bracket was repeated debonding physically, then the adhesive remained on the dental surface. The residual adhesive caused a lack of adhesive strength between dental and ceramic bracket. Since commonly used adhesive in orthodontics is translucent, residual adhesive is hard to be detected with conventional microscopes. Therefore, 1310 nm center wavelength swept-source OCT system based on laboratory customized image processing algorithm was used for the precise detection of residual adhesive on tooth surface. The algorithm separates residual adhesive from dental surface by comparing the height of adjacent B-scan images, while providing color-scaled images emphasizing the thickness information of residual adhesive. Finally, the acquired results were compared with microscopic and adhesive remnant index scoring gold standards, while the comparison confirmed the potential merits and the improvements of the proposed method over gold standards.