Cell death detection by quantitative three-dimensional single-cell tomography.

Ultrahigh-resolution optical coherence tomography (UR-OCT) has been used for the first time to our knowledge to study single-cell basal cell carcinoma (BCC) in vitro. This noninvasive, in situ, label-free technique with deep imaging depth enables three-dimensional analysis of scattering properties of single cells with cellular spatial resolution. From three-dimensional UR-OCT imaging, live and dead BCC cells can be easily identified based on morphological observation. We developed a novel method to automatically extract characteristic parameters of a single cell from data volume, and quantitative comparison and parametric analysis were performed. The results demonstrate the capability of UR-OCT to detect cell death at the cellular level.

Miniaturized video-rate epi-third-harmonic-generation fiber-microscope.

With a micro-electro-mechanical system (MEMS) mirror, we successfully developed a miniaturized epi-third-harmonic-generation (epi-THG) fiber-microscope with a video frame rate (31 Hz), which was designed for in vivo optical biopsy of human skin. With a large-mode-area (LMA) photonic crystal fiber (PCF) and a regular microscopic objective, the nonlinear distortion of the ultrafast pulses delivery could be much reduced while still achieving a 0.4 microm lateral resolution for epi-THG signals. In vivo real time virtual biopsy of the Asian skin with a video rate (31 Hz) and a sub-micron resolution was obtained. The result indicates that this miniaturized system was compact enough for the least invasive hand-held clinical use.

Prevalence of congenital dental anomalies in the primary dentition in Taiwan.

PURPOSE: The purpose of this study was to investigate the prevalence of congenital anomolies in the primary dentition in preschool Taiwanese children compared to Caucasion populations. METHODS: The study group comprised 2,611 children (1,442 boys ond 1,169 girls) between 2 and 6 years-old in the primary dentition phase using a random sampling technique. The presence of hypodontia, hyperdontia, and double teeth (fusion ond gemination) were recorded ond analyzed using Fisher's exact test. RESULTS: The prevalence of hypodontia was approximately 2%. Unilaterol missing teeth were more frequently observed than bilateral missing teeth. The primary mandibular right lateral incisor was the most frequently missing tooth. The prevalence af hyperdontia was less than 1%. All of the supernumerary teeth were located in the primary maxillary incisor area. The prevalence of double teeth was approximately 3%. All double teeth were located in the anterior region, and most of them were found in the mandibular lateral incisor and canine area. There were no differences in the prevalence of anomalies between the sexes. CONCLUSIONS: The prevalence of hypodontia and double teeth, but not hyperdontia, was significantly higher in Taiwanese children vs Caucasian children. Early detection of primary dental anomalies may help prevent oral disease in children.