Automatic and quantitative measurement of alveolar bone level in OCT images using deep learning.

We propose a method to automatically segment the periodontal structures of the tooth enamel and the alveolar bone using convolutional neural network (CNN) and to measure quantitatively and automatically the alveolar bone level (ABL) by detecting the cemento-enamel junction and the alveolar bone crest in optical coherence tomography (OCT) images. The tooth enamel and the alveolar bone regions were automatically segmented using U-Net, Dense-UNet, and U2-Net, and the ABL was quantitatively measured as the distance between the cemento-enamel junction and the alveolar bone crest using image processing. The mean distance difference (MDD) measured by our suggested method ranged from 0.19 to 0.22 mm for the alveolar bone crest (ABC) and from 0.18 to 0.32 mm for the cemento-enamel junction (CEJ). All CNN models showed the mean absolute error (MAE) of less than 0.25 mm in the x and y coordinates and greater than 90% successful detection rate (SDR) at 0.5 mm for both the ABC and the CEJ. The CNN models showed high segmentation accuracies in the tooth enamel and the alveolar bone regions, and the ABL measurements at the incisors by detected results from CNN predictions demonstrated high correlation and reliability with the ground truth in OCT images.

Hopeless tooth and less posterior occlusion is related to a greater risk of low handgrip strength: A population-based cross-sectional study.

The effect of severely compromised teeth on masticatory function has not been properly evaluated in previous studies, as they were often considered equivalent to the healthy tooth or excluded as if absent in the dentition. Hopeless teeth, which refer to non-salvageable teeth that require extraction, can interfere with masticatory function. As posterior occlusion is directly related to the masticatory function, we evaluated pairs opposing posterior teeth (POPs) that reflect the arrangement as well as the number of remaining posterior teeth. This study investigated the relationship of a hopeless tooth to handgrip strength according to POPs in the elderly. This cross-sectional study used data from the Korea National Health and Nutrition Examination Survey (KNHANES). Among the data of 23,466 participants from 2015 to 2018, participants aged 60 years or older (n = 4,729) were included. In males with POPs scores of 0-7, considered poor posterior occlusion, the association with low handgrip strength persisted in the multivariate logistic regression model adjusted for all confounding variables. The odds ratio (OR) in the absence of hopeless teeth (OR = 1.91, 95% CI: 1.02-3.59) increased in the presence of a hopeless tooth (OR = 2.78, 95% CI: 1.42-5.47). Even with POPs scores of 8-11, considered good posterior occlusion, the association was significantly high in the presence of a hopeless tooth (OR = 2.82, 95% CI: 1.06-7.52). In females, the association disappeared in adjusted models. The fewer pairs of natural posterior teeth with occlusion, the greater the risk of low handgrip strength. Dentition containing hopeless teeth increases the risk of low handgrip strength, even in dentition with sufficient posterior occlusion. Preserving the posterior teeth in a healthy condition through personal oral hygiene and regular dental management is essential for maintaining components of physical function such as handgrip strength.

Improved accuracy in periodontal pocket depth measurement using optical coherence tomography.

PURPOSE: The purpose of this study was to examine whether periodontal pocket could be satisfactorily visualized by optical coherence tomography (OCT) and to suggest quantitative methods for measuring periodontal pocket depth. METHODS: We acquired OCT images of periodontal pockets in a porcine model and determined the actual axial resolution for measuring the exact periodontal pocket depth using a calibration method. Quantitative measurements of periodontal pockets were performed by real axial resolution and compared with the results from manual periodontal probing. RESULTS: The average periodontal pocket depth measured by OCT was 3.10±0.15 mm, 4.11±0.17 mm, 5.09±0.17 mm, and 6.05±0.21 mm for each periodontal pocket model, respectively. These values were similar to those obtained by manual periodontal probing. CONCLUSIONS: OCT was able to visualize periodontal pockets and show attachment loss. By calculating the calibration factor to determine the accurate axial resolution, quantitative standards for measuring periodontal pocket depth can be established regardless of the position of periodontal pocket in the OCT image.

Epithelial-myoepithelial carcinoma of the nasopharynx: A case report and review of the literature.

An 80-year-old female with complaints of right-sided nose blockage and occasional epistaxis for several months was referred to Sanggye Paik Hospital (Seoul, Korea). Nasal examination revealed a hemorrhagic mass protruding towards the right posterior nasal cavity, for which the patient was subjected to excisional biopsy. The pathological diagnosis was epithelial-myoepithelial carcinoma, as immunohistochemical analysis revealed that the inner cells stained positive for cytokeratin 7, an epithelial cell marker, whereas the outer cells stained positive for smooth muscle actin and P63, consistent with a myoepithelial phenotype. The patient received concurrent chemoradiation therapy followed by systemic chemotherapy. Following the achievement of a partial response, the patient's treatment course was uneventful. Follow-up at 24 months revealed a stable status at partial response, with no subsequent progression.