Quantitative Evaluation of Caries and Calculus with Ultrahigh-Resolution Optical Coherence Tomography.

Dental caries on the crown's surface is caused by the interaction of bacteria and carbohydrates, which then gradually alter the tooth's structure. In addition, calculus is the root of periodontal disease. Optical coherence tomography (OCT) has been considered to be a promising tool for identifying dental caries; however, diagnosing dental caries in the early stage still remains challenging. In this study, we proposed an ultrahigh-resolution OCT (UHR-OCT) system with axial and transverse resolutions of 2.6 and 1.8 µm for differentiating the early-stage dental caries and calculus. The same teeth were also scanned by a conventional spectral-domain OCT (SD-OCT) system with an axial resolution of 7 µm. The results indicated that early-stage carious structures such as small cavities can be observed using UHR-OCT; however, the SD-OCT system with a lower resolution had difficulty identifying it. Moreover, the estimated surface roughness and the scattering coefficient of enamel were proposed for quantitatively differentiating the different stages of caries. Furthermore, the thickness of the calculus can be estimated from the UHR-OCT results. The results have demonstrated that UHR-OCT can detect caries and calculus in their early stages, showing that the proposed method for the quantitative evaluation of caries and calculus is potentially promising.

Incidence Rate and Predictors of Globus Pallidus Necrosis after Charcoal Burning Suicide.

Objective: This study examined predictors of globus pallidus necrosis as there was a paucity of literature of globus pallidus necrosis resulted from carbon monoxide poisoning after charcoal burning suicide. Methods: A total of 67 patients who had attempted charcoal burning suicide were recruited and stratified into two subgroups based on either presence (n = 40) or absence (n = 27) of globus pallidus necrosis. Demographic, clinical, laboratory, and radiographic data were obtained for cross-sectional analysis. All patients were followed to investigate the risks for mortality. Results: The patients aged 36.8 ± 11.1 years (67.2%) were male. Patients with globus pallidus necrosis were younger (p = 0.044) and had less hypertension (p = 0.015) than patients without globus pallidus necrosis. Furthermore, patients with globus pallidus necrosis suffered from severer medical complications, i.e., fever (p = 0.008), acute myocardial injury (p = 0.022), acute rhabdomyolysis (p = 0.022), and neuropsychiatric symptoms (p < 0.001) than patients without globus pallidus necrosis. Moreover, patients with globus pallidus necrosis received less hyperbaric oxygen therapy than without necrosis (p = 0.024). Two patients (3.0%) died on arrival. In a multivariable regression model, it was revealed that acute myocardial injury (odds ratio 4.6, confidence interval 1.1-18.9, p = 0.034) and neuropsychiatric symptoms (odds ratio 8.0, confidence interval 2.0-31.4, p = 0.003), decreased blood bicarbonate level (odds ratio 0.8, confidence interval 0.7-1.0, p = 0.032), and younger age (odds ratio 0.9, confidence interval 0.9-1.0, p = 0.038) were significant predictors for globus pallidus necrosis. Conclusion: Although patients who had attempted charcoal burning suicide had a low mortality rate (3.0%), globus pallidus necrosis was not uncommon (59.7%) in this population. Further studies are warranted.

Early detection of enamel demineralization by optical coherence tomography.

Enamel is the outermost layer of the tooth that protects it from invasion. In general, an acidic environment accelerates tooth demineralization, leading to the formation of cavities. Scanning electron microscopy (SEM) is conventionally used as an in vitro tool for the observation of tooth morphology changes with acid attacks. Yet, SEM has intrinsic limitations for the potential application of in vivo detection in the early demineralization process. In this study, a high-resolution optical coherence tomography (OCT) system with the axial and transverse resolutions of 2.0 and 2.7 µm in teeth has been utilized for characterizing the effect of the acidic environment (simulated by phosphoric acid) on the enamel topology. The scattering coefficient and the surface roughness of enamel can be directly derived from the OCT results, enabling a quantitative evaluation of the topology changes with demineralization. The dynamic process induced by the acid application is also recorded and analyzed with OCT, depicting the evolution of the demineralization process on enamel. Notably, the estimated enamel scattering coefficient and surface roughness significantly increase with the application time of acid and the results illustrate that the values of both parameters after demineralization are significantly larger than those obtained before the demineralization, illustrating both parameters could be effective to differentiate the healthy and demineralized teeth and determine the severity. The obtained results unambiguously illustrate that demineralization of the tooth surface can be successfully detected by OCT and further used as an indicator of early-stage cavity formation.

Development of an intervention tool for precision oral self-care: Personalized and evidence-based practice for patients with periodontal disease.

BACKGROUND: Oral self-care plays an important role in maintaining oral health and preventing the occurrence of oral diseases. The association between good oral care and good oral hygiene is well known. However, the adherence to a proper daily oral hygiene regimen generally remains poor, so the prevalence of oral diseases remains high. Periodontal disease is the most common oral disease in the population. To enhance the adherence to good oral hygiene behaviors for patients with periodontal disease, we developed a personalized and evidence-based mobile application as an intervention tool for the purpose of initiating and improving good oral self-care. OBJECTIVE: The objective of this study was to demonstrate the systematic development process and content of the oral self-care mobile application, OSCA. METHODS: The systematic development process of OSCA consists of three phases: behavioral diagnosis, intervention design, and assessment of OSCA. Firstly, behavioral problem of oral self-care was identified by the experts in periodontics care. Secondly, the intervention functions and the mode of delivery were designed based on the capability-opportunity-motivation behavioral model, which is the underpinning model behind the behavior change wheel framework. Thirdly, the developed app was evaluated by the experts through a heuristics evaluation checklist by adopting Morville's Honeycomb model, and the final version of OSCA was assessed by the patients with periodontal disease using the System Usability Scale (SUS). RESULTS: The problems of target behavior were identified and incorporated into the design of intervention functions. For the beta version of the OSCA, experts proposed four main suggestions to improve the usefulness. Experts evaluated the beta and final versions of the app using a heuristics evaluation checklist, providing mean scores of 4.38 and 4.62, respectively. For usability testing, 87 participants completed both the specified tasks and the SUS questionnaire, providing an SUS median score of 77.5 (IQR = 12.5) and an overall mean completion time of 12.22 minutes for the specified tasks. The mean scores of the intervention functions for capability establishment, motivation enhancement, and opportunity creation were 6.13, 5.88, and 6.06, respectively. CONCLUSIONS: The study presents a rigorous design process of developing an evidence-based and personalized mobile application for oral self-care. The results of the expert evaluation confirmed the validated design and the participants were satisfied with the designed app.

Isolation of Mesenchymal Stem Cells from Human Alveolar Periosteum and Effects of Vitamin D on Osteogenic Activity of Periosteum-derived Cells.

Mesenchymal stem cells (MSCs) are present in a variety of tissues and can be differentiated into numerous cell types, including osteoblasts. Among the dental sources of MSCs, the periosteum is an easily accessible tissue, which has been identified to contain MSCs in the cambium layer. However, this source has not yet been widely studied. Vitamin D3 and 1,25-(OH)2D3 have been demonstrated to stimulate in vitro differentiation of MSCs into osteoblasts. In addition, vitamin C facilitates collagen formation and bone cell growth. However, no study has yet investigated the effects of Vitamin D3 and Vitamin C on MSCs. Here, we present a method of isolating MSCs from human alveolar periosteum and examine the hypothesis that 1,25-(OH)2D3 may exert an osteoinductive effect on these cells. We also investigate the presence of MSCs in the human alveolar periosteum and assess stem cell adhesion and proliferation. To assess the ability of vitamin C (as a control) and various concentrations of 1,25-(OH)2D3 (10-10, 10-9, 10-8, and 10-7 M) to alter key mRNA biomarkers in isolated MSCs mRNA expression of alkaline phosphatase (ALP), bone sialoprotein (BSP), core binding factor alpha-1 (CBFA1), collagen-1, and osteocalcin (OCN) are measured using real-time polymerase chain reaction (RT-PCR).

Noninvasive structural and microvascular anatomy of oral mucosae using handheld optical coherence tomography.

In this study, we demonstrated the feasibility of using a handheld optical coherence tomography (OCT) for in vivo visualizations of the microstructural and microvascular features of various oral mucosal types. To scan arbitrary locations of the oral mucosa, a scanning probe was developed, composed of a probe body fabricated by a 3D printer, miniaturized two-axis galvanometer, relay lenses, and reflective prism. With a 3D printing technique, the probe weight and the system volume were greatly reduced, enabling the effective improvement of imaging artifacts from unconscious motion and system complexity. Additionally, in our design, the distal end of the probe can be switched to fit various oral conditions, and the optical parameters of the probe, such as the transverse resolution, working distance, and probe length can be easily varied. The results showed that the epithelium and lamina propria layers, as well as the fungiform papilla and salivary gland, were differentiated. Moreover, various microcirculation features at different mucosal sites were identified that are potentially effective indicators for the diagnosis of premalignant lesions. The demonstrated results indicate that the developed OCT system is a promising tool for noninvasive imaging of oral mucosae.

Decreased Amount of Supporting Alveolar Bone at Single-Rooted Premolars Is Under Estimated by 2D Examinations.

The purpose of this study was to relate the proportions of bone-supported root length of a 2D view into the amount of a 3D bone-attached root surface area (BA-RSA) by using a dental laser scanner examination. White-light 3D scanning technology was used to probe 36 maxillary and 35 mandibular single-rooted premolars. The bone-supported height (BSH) and BA-RSA at designated levels (95-25%) were compared using statistical t tests. The 100% BSH and BA-RSA of the maxillary/mandibular premolars were 12.6 ± 1.60 mm/13.45 ± 1.47 mm (p < 0.05) and 220.78 ± 35.31 mm2/199.51 ± 26.33 mm2 (p < 0.01), respectively. Approximately 79-80%, 59-60%, and 35-36% premolars 2D BSH remained in comparison to 75%, 50%, and 25% 3D BA-RSA preservation, respectively. However, corresponding to a 75%, 50%, and 25% 2D BSH reserve, premolars retained 67-68%, 39-41%, and 15-17% 3D BA-RSA, respectively. When taking 1.0 mm connective tissue attachment into account, 60% 3D BA-RSA and 50% 2D BSH loss were noted at the 5.1-5.4 mm clinical attachment level. Assigning a periodontal prognosis and determining the severity of periodontitis for premolars with alveolar bone loss based on 3D's or 2D's measurement is inconsistent.

MicroRNA-134 Contributes to Glucose-Induced Endothelial Cell Dysfunction and This Effect Can Be Reversed by Far-Infrared Irradiation.

Diabetes mellitus (DM) is a metabolic disease that is increasing worldwide. Furthermore, it is associated with the deregulation of vascular-related functions, which can develop into major complications among DM patients. Endothelial colony forming cells (ECFCs) have the potential to bring about medical repairs because of their post-natal angiogenic activities; however, such activities are impaired by high glucose- (HG) and the DM-associated conditions. Far-infrared radiation (FIR) transfers energy as heat that is perceived by the thermoreceptors in human skin. Several studies have revealed that FIR improves vascular endothelial functioning and boost angiogenesis. FIR has been used as anti-inflammatory therapy and as a clinical treatment for peripheral circulation improvement. In addition to vascular repair, there is increasing evidence to show that FIR can be applied to a variety of diseases, including cardiovascular disorders, hypertension and arthritis. Yet mechanism of action of FIR and the biomarkers that indicate FIR effects remain unclear. MicroRNA-134 (miR-134-5p) was identified by small RNA sequencing as being increased in high glucose (HG) treated dfECFCs (HG-dfECFCs). Highly expressed miR-134 was also validated in dmECFCs by RT-qPCR and it is associated with impaired angiogenic activities of ECFCs. The functioning of ECFCs is improved by FIR treatment and this occurs via a reduction in the level of miR-134 and an increase in the NRIP1 transcript, a direct target of miR-134. Using a mouse ischemic hindlimb model, the recovery of impaired blood flow in the presence of HG-dfECFCs was improved by FIR pretreatment and this enhanced functionality was decreased when there was miR-134 overexpression in the FIR pretreated HG-dfECFCs. In conclusion, our results reveal that the deregulation of miR-134 is involved in angiogenic defects found in DM patients. FIR treatment improves the angiogenic activity of HG-dfECFCs and dmECFCs and FIR has potential as a treatment for DM. Detection of miR-134 expression in FIR-treated ECFCs should help us to explore further the effectiveness of FIR therapy.

Potential Osteoinductive Effects of Calcitriol on the m-RNA of Mesenchymal Stem Cells Derived from Human Alveolar Periosteum.

This study characterized alveolar periosteum-derived mesenchymal stem cells (P-MSCs) and examined the hypothesis that 1,25-(OH)2D3 (calcitriol) exerts osteoinductive effects on P-MSCs. The mRNA expressions of alkaline phosphatase (ALP), bone sialoprotein (BSP), core-binding factor alpha-1 (CBFA1), collagen-1 (Col-1), osteocalcin (OCN), and vitamin D3 receptor (VDR) were assessed after incubation with calcitriol for 2 weeks. Vitamin C as positive control (Vit. C-p) increased ALP and CBFA1 mRNA expression at both 1 and 2 weeks and increased BSP and Col-1 mRNA expression only at the first week. A concentration of 10-8 M calcitriol enhanced ALP, CBFA1, Col-1, and OCN mRNA expression at both weeks and BSP mRNA expression at the first week. Furthermore, 10-7 M calcitriol increased the mRNA expressions of all compounds at both weeks, except that of CBFA1 at the first week. 10-8 M calcitriol and Vit. C-p enhanced ALP activity at the second and third weeks. The results revealed that 10-9, 10-8, and 10-7 M calcitriol induced osteoinduction in alveolar P-MSCs by increasing ALP, CBFA1, Col-1, and OCN mRNA expression. A 10-7 M calcitriol yielded a higher mRNA expression than Vit. Cp on VDR and OCN mRNA expression at both weeks and on Col-1 mRNA at the second week.

miRNome traits analysis on endothelial lineage cells discloses biomarker potential circulating microRNAs which affect progenitor activities.

BACKGROUND: Endothelial progenitor cells (EPCs) play a fundamental role in not only blood vessel development but also post-natal vascular repair. Currently EPCs are defined as early and late EPCs based on their biological properties and their time of appearance during in vitro culture. Both EPC types assist angiogenesis and have been linked to ischemia-related disorders, including coronary artery disease (CAD). RESULTS: We found late EPCs are more mobile than early EPCs and matured endothelial cells (ECs). To pinpoint the mechanism, microRNA profiles of early EPCs late EPCs, and ECs were deciphered by small RNA sequencing. Obtained signatures made up of both novel and known microRNAs, in which anti-angiogenic microRNAs such as miR-221 and miR-222 are more abundant in matured ECs than in late EPCs. Overexpression of miR-221 and miR-222 resulted in the reduction of genes involved in hypoxia response, metabolism, TGF-beta signalling, and cell motion. Not only hamper late EPC activities in vitro, both microRNAs (especially miR-222) also hindered in vivo vasculogenesis in a zebrafish model. Reporter assays showed that miR-222, but not miR-221, targets the angiogenic factor ETS1. In contrast, PIK3R1 is the target of miR-221, but not miR-222 in late EPCs. Clinically, both miR-221-PIK3R1 and miR-222-ETS1 pairs are deregulated in late EPCs of CAD patients. CONCLUSIONS: Our results illustrate EPCs and ECs exploit unique miRNA modalities to regulate angiogenic features, and explain why late EPC levels and activities are reduced in CAD patients. These data will further help to develop new plasma biomarkers and therapeutic approaches for ischemia-related diseases or tumor angiogenesis.

Association between maternal periodontal disease and preterm delivery and low birth weight.

OBJECTIVE: It has been suggested that periodontal disease is an important risk factor for preterm low birth weight (PLBW). The purpose of this study was to determine the association of maternal periodontitis with low birth weight (LBW) and preterm birth (PB). MATERIALS AND METHODS: Pregnant women (n = 211) aged 22-40 years were enrolled while receiving prenatal care. Dental plaque, probing depth, bleeding on probing, and clinical attachment level were used as criteria to classify three groups: a healthy group (HG; n = 82), a gingivitis group (GG; n = 67), and a periodontitis group (PG; n = 62). At delivery, birth weight was recorded. RESULTS: Mean infant weight at delivery was 3084.9 g. The total incidence of preterm birth and LBW infants was 10.4% and 8.1%, respectively. The incidence of LBW infants was 4.2% for term and 40.9% for preterm gestations. Maternal height was not correlated with infant birth weight (p = 0.245). Significant differences in mean infant birth weight were observed among the HG, GG, and PG groups (p = 0.030). No significant relationship was found between periodontal disease and PB, but the association between periodontal disease and LBW was significant. CONCLUSION: After appropriately controlling for confounding variables, our results do not support the hypothesis of an association that was observed in previous studies of maternal periodontal disease and infant PB, but the association between periodontal disease and LBW is significant.