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Purpose: This experiment aimed to observe the differences in biological properties by producing BGS-7 + PCL scaffolds with different weight fractions of BGS-7 through 3D printing and to confirm whether using the scaffold for vertical bone augmentation is effective., Materials and Methods: Cube-shaped bioglass (BGS-7) and polycaprolactone (PCL) scaffolds with different weight fractions (PCL alone, PCL with 15% and 30% BGS-7) are produced using 3D printing. The surface hydroxyapatite (HA) apposition, the pH change, proliferation and attachment assays, and various gene expression levels are assessed. After a 7-mm implant was inserted 3 mm into the rabbit calvaria, vertical bone augmentation is performed around the implant and inside the scaffold in four ways: scaffold only, scaffold+bone graft, bone graft only, and no graft. Sacrifice is performed at 6, 12, and 24 weeks, and the various parameters are compared radiographically and histologically., Results: HA apposition, cell proliferation, cell attachment, and expression of osteogenic genes increase as the proportion of BGS-7 increase. In the in vivo test, a higher bone-implant contact ratio, bone volume ratio, bone mineral density, and new bone area are observed when the scaffold and bone grafts were used together., Conclusion: The 3D-printed scaffold, a mixture of BGS-7 and PCL, exhibit higher biological compatibility as the proportion of BGS-7 increase. Additionally, the use of scaffold is effective for vertical bone augmentation., (© 2024 Wiley Periodicals LLC.)

Objectives: This review aims to explore recent advancements in optical imaging techniques for monitoring the viability of Deep Inferior Epigastric Perforator (DIEP) flap reconstruction. The objectives include highlighting the principles, applications, and clinical utility of optical imaging modalities such as near-infrared spectroscopy (NIRS), indocyanine green (ICG) fluorescence angiography, laser speckle contrast imaging (LSCI), hyperspectral imaging (HSI), dynamic infrared thermography (DIRT), and short-wave infrared thermography (SWIR) in assessing tissue perfusion and oxygenation. Additionally, this review aims to discuss the potential of these techniques in enhancing surgical outcomes by enabling timely intervention in cases of compromised flap perfusion., Materials and Methods: A comprehensive literature review was conducted to identify studies focusing on optical imaging techniques for monitoring DIEP flap viability. We searched PubMed, MEDLINE, and relevant databases, including Google Scholar, Web of Science, Scopus, PsycINFO, IEEE Xplore, and ProQuest Dissertations & Theses, among others, using specific keywords related to optical imaging, DIEP flap reconstruction, tissue perfusion, and surgical outcomes. This extensive search ensured we gathered comprehensive data for our analysis. Articles discussing the principles, applications, and clinical use of NIRS, ICG fluorescence angiography, LSCI, HSI, DIRT, and SWIR in DIEP flap monitoring were selected for inclusion. Data regarding the techniques' effectiveness, advantages, limitations, and potential impact on surgical decision-making were extracted and synthesized., Results: Optical imaging modalities, including NIRS, ICG fluorescence angiography, LSCI, HSI, DIRT, and SWIR offer a non- or minimal-invasive, real-time assessment of tissue perfusion and oxygenation in DIEP flap reconstruction. These techniques provide objective and quantitative data, enabling surgeons to monitor flap viability accurately. Studies have demonstrated the effectiveness of optical imaging in detecting compromised perfusion and facilitating timely intervention, thereby reducing the risk of flap complications such as partial or total loss. Furthermore, optical imaging modalities have shown promise in improving surgical outcomes by guiding intraoperative decision-making and optimizing patient care., Conclusions: Recent advancements in optical imaging techniques present valuable tools for monitoring the viability of DIEP flap reconstruction. NIRS, ICG fluorescence angiography, LSCI, HSI, DIRT, and SWIR offer a non- or minimal-invasive, real-time assessment of tissue perfusion and oxygenation, enabling accurate evaluation of flap viability. These modalities have the potential to enhance surgical outcomes by facilitating timely intervention in cases of compromised perfusion, thereby reducing the risk of flap complications. Incorporating optical imaging into clinical practice can provide surgeons with objective and quantitative data, assisting in informed decision-making for optimal patient care in DIEP flap reconstruction surgeries.

This study aimed to measure masticatory performance (MP) using β-carotene gummy jelly to investigate its relationship with skeletal properties in decompensated patients diagnosed with skeletal class III malocclusion. The study included 78 patients (38 men and 40 women) diagnosed with skeletal class III malocclusion without temporomandibular joint disorder and periodontal disease. MP was measured using a new masticatory measuring device and β-carotene in the gummy jelly. Lateral and posteroanterior cephalograms were obtained, and skeletal properties (Me deviation, ANB, SNB, APDI, Wits, ODI, facial axis, body length, ramus length, SN-GoGn, anterior facial height, posterior facial height, saddle angle, articular angle, and gonial angle) were evaluated. MP differences according to age and sex and the effect of skeletal properties on MP were analyzed using multiple linear regression analysis. The MP of all patients was 3690.55±1428.77 mm², MP of the male group was 4043.05±1498.09 mm², and MP of the female group was 3355.68±1272.19 mm². Among the items investigated, the variable that affected MP was posterior facial height. Posterior facial height showed a positive correlation (P=0.022). There was no significant difference between MP and other skeletal properties (P>0.05). The severity of the hypodivergency in skeletal class III could affect MP. The relationship between facial asymmetry or skeletal relation and MP could not be explained in this study., Competing Interests: The authors report no conflicts of interest., (Copyright © 2024 by Mutaz B. Habal, MD.)

This study employs machine learning analysis with population data for the associations of preterm birth (PTB) with temporomandibular disorder (TMD) and gastrointestinal diseases. The source of the population-based retrospective cohort was Korea National Health Insurance claims for 489,893 primiparous women with delivery at the age of 25-40 in 2017. The dependent variable was PTB in 2017. Twenty-one predictors were included, i.e., demographic, socioeconomic, disease and medication information during 2002-2016. Random forest variable importance was derived for finding important predictors of PTB and evaluating its associations with the predictors including TMD and gastroesophageal reflux disease (GERD). Shapley Additive Explanation (SHAP) values were calculated to analyze the directions of these associations. The random forest with oversampling registered a much higher area under the receiver-operating-characteristic curve compared to logistic regression with oversampling, i.e., 79.3% vs. 53.1%. According to random forest variable importance values and rankings, PTB has strong associations with low socioeconomic status, GERD, age, infertility, irritable bowel syndrome, diabetes, TMD, salivary gland disease, hypertension, tricyclic antidepressant and benzodiazepine. In terms of max SHAP values, these associations were positive, e.g., low socioeconomic status (0.29), age (0.21), GERD (0.27) and TMD (0.23). The inclusion of low socioeconomic status, age, GERD or TMD into the random forest will increase the probability of PTB by 0.29, 0.21, 0.27 or 0.23. A cutting-edge approach of explainable artificial intelligence highlights the strong associations of preterm birth with temporomandibular disorder, gastrointestinal diseases and antidepressant medication. Close surveillance is needed for pregnant women regarding these multiple risks at the same time., Competing Interests: The authors declare no competing interest., (Copyright: © 2024 Lee et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

This study aimed to investigate the effects of shift work on periodontal disease in blue-and white-collar workers and to examine the interaction effects between occupation and work patterns. Data were collected from the Korea National Health and Nutrition Examination Survey conducted by the Korean Ministry of Health and Welfare for a total of nine years from 2007 to 2015. Participants with missing outcome variables were excluded from the analysis and a total of 32,336 participants were included in the final analysis. Univariable odds ratios (OR) were calculated using a logistic regression model with 95% confidence interval (CI). A multivariable logistic regression analysis was performed using the backward elimination method. The CONTRAST statement was used to analyze the interaction effect between occupation and work patterns. Multivariable logistic regression analysis revealed that interaction effects are present between the terms, occupational type and work pattern. Crude OR of shift work for periodontitis was 1.269 [CI 1.213-1.327, P < 0.05]. However, following adjustment for multiple confounding factors and the interaction effect term considered, this OR (1.269) increased to 1.381 [CI 1.253-1.523] in white-collar group while it decreased to 1.198 [1.119-1.283] in blue-collar. Crude OR of blue-collar (OR = 3.123, CI 2.972-3.281, P < 0.05) decreased to 1.151 [CI 1.049-1.262] when interaction effect to the shift work was considered. Shift work pattern increases the risk for periodontitis and this adverse effect is greater when white-collar workers are engaged comparing to blue-collar. The result of this study suggests that 24/7 lifestyle of the modern society poses health risks to the relevant people and the potential harm can be greater to white-collar workers., (© 2023. Springer Nature Limited.)

The aim of this study was to convert medical images stored in 3 mm slices in the picture archiving and communication system (PACS) to 1 mm slices, using artificial intelligence (AI), and to analyze the accuracy of the AI. The original 1.0 mm CT slices of the facial bone were obtained from 30 patients and reformatted to a rough CT slice of 3.0 mm. CT slices of 1.0 mm were subsequently reconstructed from those of 3.0 mm using AI. The AI and rough CT images were superimposed on the original CT images. Fourteen hard-tissue and five soft-tissue landmarks were selected for measuring the discrepancy. The overall average differences in values for the hard-tissue landmarks were 1.31 ± 0.38 mm and 0.81 ± 0.17 mm for the rough and AI CT images, respectively. The values for the soft-tissue landmarks were 1.18 ± 0.35 mm and 0.54 ± 0.17 mm for the rough and AI CT images, respectively. The differences for all the landmarks, excluding point A and pogonion, were statistically significant. Within the limitations of the study it seems that CT images reconstructed using AI might provide more accurate clinical information with a discrepancy of less than 1.0 mm., (Copyright © 2023 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Objectives: This study aimed to evaluate the effect of aging on the changes in implant stability over time following implant placement., Materials and Methods: A total of 104 patients in four age ranges (group 1: <60 years, group 2: 61-70 years, group 3: 71-80 years, and group 4: >80 years) were included. Bone-level tapered implants were placed without implementing any bone augmentation procedure. The final torque value displayed on the implant engine during implant insertion was recorded. Cone-beam computed tomography (CBCT) was performed immediately after surgery to analyze the bone quality around the implant. Implant stability was measured immediately after surgery and 2, 4, and 8 weeks after surgery., Results: In the CBCT image, higher grayscale values were observed in the order of group 1, group 2, and groups 3/4, with statistical significance (p < .05). There was no significant difference in the insertion torque values between age groups (p ≥ .05). Groups 1 and 2 showed lower implant stability values after 2 and 4 weeks compared to immediately and 8 weeks after surgery (p < .05); however, groups 3 and 4 showed no significant difference between the results measured at different timepoints (p ≥ .05)., Conclusions: Implant treatment in elderly patients is successful showing a settled implant stability over time following implant placement when the implant is appropriately engaged in the alveolar bone in the absence of bone augmentation., (© 2023 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

This study hypothesizes that the application of low-dose nonthermal biocompatible dielectric barrier discharge plasma (DBD-NBP) to human gingival fibroblasts (HGFs) will inhibit colony formation but not cell death and induce matrix metalloproteinase (MMP) expression, extracellular matrix (ECM) degradation, and subsequent cell migration, which can result in enhanced wound healing. HGFs treated with plasma for 3 min migrate to each other across the gap faster than those in the control and 5-min treatment groups on days 1 and 3. The plasma-treated HGFs show significantly high expression levels of the cell cycle arrest-related p21 gene and enhanced MMP activity. Focal adhesion kinase (FAK) mediated attenuation of wound healing or actin cytoskeleton rearrangement, and plasma-mediated reversal of this attenuation support the migratory effect of DBD-NBP. Further, this work performs computer simulations to investigate the effect of oxidation on the stability and conformation of the catalytic kinase domain (KD) of FAK. It is found that the oxidation of highly reactive amino acids (AAs) Cys427, Met442, Cys559, Met571, Met617, and Met643 changes the conformation and increases the structural flexibility of the FAK protein and thus modulates its function and activity. Low-dose DBD-NBP-induces host cell cycle arrest, ECM breakdown, and subsequent migration, thus contributing to the enhanced wound healing process., (© 2022 Wiley-VCH GmbH.)

Background: This study uses machine learning with large-scale population data to assess the associations of preterm birth (PTB) with dental and gastrointestinal diseases., Methods: Population-based retrospective cohort data came from Korea National Health Insurance claims for 124,606 primiparous women aged 25-40 and delivered in 2017. The 186 independent variables included demographic/socioeconomic determinants, disease information, and medication history. Machine learning analysis was used to establish the prediction model of PTB. Random forest variable importance was used for identifying major determinants of PTB and testing its associations with dental and gastrointestinal diseases, medication history, and socioeconomic status., Results: The random forest with oversampling data registered an accuracy of 84.03, and the areas under the receiver-operating-characteristic curves with the range of 84.03-84.04. Based on random forest variable importance with oversampling data, PTB has strong associations with socioeconomic status (0.284), age (0.214), year 2014 gastroesophageal reflux disease (GERD) (0.026), year 2015 GERD (0.026), year 2013 GERD (0.024), progesterone (0.024), year 2012 GERD (0.023), year 2011 GERD (0.021), tricyclic antidepressant (0.020) and year 2016 infertility (0.019). For example, the accuracy of the model will decrease by 28.4%, 2.6%, or 1.9% if the values of socioeconomic status, year 2014 GERD, or year 2016 infertility are randomly permutated (or shuffled)., Conclusion: By using machine learning, we established a valid prediction model for PTB. PTB has strong associations with GERD and infertility. Pregnant women need close surveillance for gastrointestinal and obstetric risks at the same time.

We demonstrate a new type of multifocal and extended depth of focus (EDOF) intraocular lenses (IOLs) embedding μm-thin geometric phase (GP) lens layers. As an emerging approach for lens phase design, the GP modulated IOLs outperform conventional diffractive IOLs in multifocality while completely avoiding the clinically undesirable demand for additional surface patterns to standard monofocal IOL designs. The number of foci and light splitting ratio of the GP IOLs are adjusted by changing the number of stacked GP layers and the thickness of each layer. Bifocal and trifocal GP IOLs are fabricated by radial alignment of anisotropic orientation in UV-curable liquid crystal polymers. After characterizing the defocus image and modulation transfer function of the GP IOLs, it is expected that GP IOLs will alleviate the most common problems associated with multifocal and EDOF IOLs, blurred vision and photic phenomena caused by light scattering and posterior capsule opacification., (© 2022. The Author(s).)

Objective: To investigate the role of periodontitis in the risk of acute and chronic coronary syndrome with compounding factors, including sociodemographic factors and medication use., Methods: This retrospective cohort study used nationwide, population-based data from the Korean National Health Insurance Service-Health Screening Cohort database (514,866 individuals, 40-79 years). Propensity score matching was used for analysis. Information of subjects for 12 years was included. Socioeconomic and clinical factors were recorded and analysed., Results: The periodontitis group had a greater risk of overall acute coronary syndrome (hazard ratio [95% confidence interval] =1.25 [1.15, 1.35], p < .001) and non-fatal acute coronary syndrome (1.26 [1.16, 1.37], p < .001). The hazard ratio for chronic coronary syndrome was higher in patients with periodontitis (1.35 [1.25, 1.46], p < .001). The cumulative incidence of both acute and chronic coronary syndrome gradually increased, and the hazard ratios reached 1.25 and 1.35 at the 12-year follow-up, respectively. Subgroup analysis revealed that periodontitis had a significantly greater link with acute coronary syndrome incidence in males, younger adults, smokers and subjects without hypertension (p < .01) and with chronic coronary syndrome incidence in smokers, subjects without hypertension and subjects without dyslipidaemia (p < .05)., Conclusions: Periodontitis is associated with an increased risk of acute and chronic coronary syndrome., (© 2021 Wiley Periodicals LLC.)

Background and Objectives: To evaluate the stability of a dental implant and the effectiveness of a newly designed damping capacity assessment device by improving the number of blows and strength evaluated by a prospective clinical study. Materials and Method: The stability of dental implants was measured in 50 implants in a total of 38 patients. Measurements were performed using Anycheck and Periotest M devices, twice in total, divided into buccal and lingual directions. In addition, measurements were performed on the day of surgery, two weeks, one month, two months, and three months after surgery for a total of five times. After the standardization of the measured values, the differences and changes over time for each device were observed. Result: No difference in standardized values between the two devices was observed at any time point. In both devices, stability decreased at two weeks postoperatively but gradually increased thereafter. No differences were observed in the values according to the measurement direction. Conclusions: The damping capacity of Anycheck was similar to that of Periotest M. After a slight decrease in stability two weeks after implant placement, implant stability increased over time.

Objectives: Recently a modified high-submandibular approach (HSMA) has been introduced for treatment of condylar fracture. This approach involves an incision line close to the mandibular angle and transmasseteric transection, leading to a low incidence of facial palsy and allowing good visualization of the condyle area, especially the condylar neck and subcondyle positions. This study reports several cases managed with this modified HSMA technique for treating condylar fractures., Materials and Methods: Six cases of condylar fractures treated with modified HSMA technique were reviewed., Results: Three unilateral subcondylar fracture, 1 bilateral subcondylar fracture, 1 unilateral condylar neck fracture, 1 unlateral simultaneous condylar neck and subcondylar fracture cases were reviewed. All the cases were successfully treated without any major complication., Conclusion: Reduction, fixation, and osteosynthesis of condylar fractures via the modified HSMA technique enabled effective and stable treatment outcomes. Therefore, the described approach can be used especially for subcondylar and condylar neck fractures with minimal complications.

Background: Hyposalivation is disease with multiple symptoms. This disease is hard to be diagnosed and to be treated, and there are not enough clinical protocols to cure the disease. In this study, we propose our own treatment protocols which aim not only to cure the disease but also to care for the disease-related symptoms., Methods: At the 1st visit, we collect patient-related information. This procedure includes an intraoral exam, patient history taking, VAS value and unstimulated whole saliva (UWS) measurement, and salivary buffer test. Following the interview and oral examination, objective results are obtained by radiological image, CT, and sialoscintigraphy. At the 2nd visit, we analyze radiographic images including neck CT and salivary scintigraphy. These images can allow accurate diagnosis and help the patients to better understand the current condition. Depending on the severity of symptoms and patient's discomfort, we try a surgical approach at the 3rd visit, sialendoscopy., Results: With treatment, we can manage the discomfort of patients in daily life. The VAS value of hyposalivation patients dropped gradually with the trial of sialendoscopy. In the case of Sjogren's syndrome patients, the treatment efficacy has been decreased with low reactivity of treatment. The true meaning of this treatment is in not only curing the disease, but also caring for the disrupted patients. Overall, the amount of UWS increased with the progress after the procedure. Especially in the lower UWS at the 1st visit, there was a more significant increase after the procedure., Conclusion: Although many factors that cause hyposalivation have not been identified, the efficacy of sialendoscopy to relieve discomfort in hyposalivation patients has been observed. However, treatment was more difficult and complicated in the group of patients with systemic disease. This study will not only present a treatment protocol for hyposalivation patients, but also consider methods for diagnosing more precisely and improving treatment efficacy. Hyposalivation is a curable and manageable disease in some cases, so interpretation between the clinician and the patient is important., (© 2022. The Author(s).)

Background: The purpose of this study is to compare and analyze the treatment outcomes between two groups which are both immediately placed implant cases, one is immediate loading, and the other is conventional loading group., Methods: Medical records of the patients who underwent implant treatment which were immediately placed after tooth extraction were analyzed. Demographic data were collected and by using periapical or panoramic radiographic image, marginal bone level and distant crestal bone level were measured. Marginal bone change over time was analyzed and compared between immediate loading group and conventional loading group., Results: A total of 71 patients, 112 immediately placed implants after tooth extraction were initially involved. Measuring was done with implants which had not failed (81). 10 implants were had failed and removed. The others were excluded because of follow-up loss, absence of radiographic image, etc. Demographic data were collected, and measured values were averaged at each follow-up and showed in linear graphs., Conclusions: In case of immediate implantation of dental implant after extraction, loading time could affect marginal bone level or biological width of the implant. Immediate loading group showed 0.92 mm (mean value) more bone loss compared to conventional loading group at bone-implant contact points 24 months after implantation. At distant crestal points, there was no noticeable difference in bone change pattern between two groups., (© 2022. The Author(s).)

The objective of this retrospective study is to verify the effectiveness and safety of patient-specific titanium implants on maxillofacial bones, with a long-term follow-up. Total 16 patients with various maxillofacial defects underwent reconstruction using patient-specific titanium implants. Titanium implants, manufactured by electron beam melting, selective laser sintering, or milling, were inserted into the maxilla, mandible, or zygoma. Long-term follow-up (36.7 ± 20.1 months) was conducted after the surgery. Bone fusion of the titanium implant body, postoperative infection, implant malunion, functional results, patient satisfaction, subsidence, osteolysis around the implants, and complications were recorded and analyzed at the last follow-up. Of the 28 implants, only one failed to unite with the bone; therefore, revision surgery was performed. No osteolysis or subsidence around the titanium implants nor adverse events were observed; the mean VAS score for satisfaction was 9. All patients enrolled in this trial were esthetically and functionally satisfied with their surgical results, and fixation failure and esthetic dissatisfaction complications were well resolved. Patient-specific titanium showed satisfactory outcomes when used to treat various oral and maxillofacial defects. A 3D printed titanium implant can be effectively used in the reconstruction of the zygoma and mandible instead of autogenous bone without donor site morbidity., (© 2022. The Author(s).)

Purpose: To use machine learning and population data for testing the associations of preterm birth with socioeconomic status, gastroesophageal reflux disease (GERD) and medication history including proton pump inhibitors, sleeping pills and antidepressants., Methods: Population-based retrospective cohort data came from Korea National Health Insurance Service claims data for all women who aged 25-40 years and gave births for the first time as singleton pregnancy during 2015-2017 (405,586 women). The dependent variable was preterm birth during 2015-2017 and 65 independent variables were included (demographic/socioeconomic determinants, disease information, medication history, obstetric information). Random forest variable importance (outcome measure) was used for identifying major determinants of preterm birth and testing its associations with socioeconomic status, GERD and medication history including proton pump inhibitors, sleeping pills and antidepressants., Results: Based on random forest variable importance, major determinants of preterm birth during 2015-2017 were socioeconomic status (645.34), age (556.86), proton pump inhibitors (107.61), GERD for the years 2014, 2012 and 2013 (106.78, 105.87 and 104.96), sleeping pills (97.23), GERD for the years 2010, 2011 and 2009 (95.56, 94.84 and 93.81), and antidepressants (90.13)., Conclusion: Preterm birth has strong associations with low socioeconomic status, GERD and medication history such as proton pump inhibitors, sleeping pills and antidepressants. For preventing preterm birth, appropriate medication would be needed alongside preventive measures for GERD and the promotion of socioeconomic status for pregnant women., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

This study employs machine learning and population data for testing the associations of preterm birth with inflammatory bowel disease (IBD), salivary gland disease, socioeconomic status and medication history, including proton pump inhibitors. The source of population-based retrospective cohort data was the Korea National Health Insurance Service claims data for all women aged 25-40 years and who experience their first childbirths as singleton pregnancy during 2015 to 2017 (402,092 women). These participants were divided into the Ulcerative Colitis (UC) Group (1782 women), the Crohn Group (1954 women) and the Non-IBD Group (398,219 women). For each group, the dependent variable was preterm birth during 2015-2017, and 51 independent variables were included. Random forest variable importance was employed for investigating the main factors of preterm birth and testing its associations with salivary gland disease, socioeconomic status and medication history for each group. The proportion of preterm birth was higher for the UC Group and the Non-IBD Group than for the Crohn Group: 7.86%, 7.17% vs. 6.76%. Based on random forest variable importance, salivary gland disease was a top 10 determinant for the prediction of preterm birth for the UC Group, but this was not the case for the Crohn Group or the Non-IBD Group. The top 5 variables of preterm birth for the UC Group during 2015-2017 were socioeconomic status (8.58), age (8.00), proton pump inhibitors (2.35), progesterone (2.13) and salivary gland disease in 2014 (1.72). In conclusion, preterm birth has strong associations with ulcerative colitis, salivary gland disease, socioeconomic status and medication history including proton pump inhibitors.

Purpose: To evaluate the image quality of intraocular lenses (IOLs) using field-tracing optical simulation and then compare it with the image quality using conventional ray-tracing simulation., Methods: We simulated aspheric IOLs with a decenter, tilt, and no misalignment using an aspheric corneal eye model with a positive spherical aberration. The retinal image, Strehl ratio, and modulation transfer function (MTF) were compared between the ray-tracing and field-tracing optical simulation and confirmed by the results reported in an in vitro experiment using the same eye model., Results: The retinal image showed interference fringes from target due to diffraction from the object in a field-tracing simulation. When compared with the experimental results, the field tracing represented the experimental results more precisely than ray tracing after passing over 400 μm of the decentration and 4 degrees of the tilt of the IOLs. The MTF values showed similar results for the case of no IOL misalignment in both the field tracing and ray tracing. In the case of the 200-μm decentration or 8-degree tilt of IOL, the field-traced MTF shows lower values than the ray-traced one., Conclusions: The field-tracing optical bench simulation is a reliable method to evaluate IOL performance according to the IOL misalignment. It can provide retinal image quality close to real by taking into account the wave nature of light, interference and diffraction to explain to patients having the IOL misalignment., Competing Interests: NO authors have competing interests

Background: The inferior alveolar nerve (IAN) innervates and regulates the sensation of the mandibular teeth and lower lip. The position of the IAN should be monitored prior to surgery. Therefore, a study using artificial intelligence (AI) was planned to image and track the position of the IAN automatically for a quicker and safer surgery., Methods: A total of 138 cone-beam computed tomography datasets (Internal: 98, External: 40) collected from multiple centers (three hospitals) were used in the study. A customized 3D nnU-Net was used for image segmentation. Active learning, which consists of three steps, was carried out in iterations for 83 datasets with cumulative additions after each step. Subsequently, the accuracy of the model for IAN segmentation was evaluated using the 50 datasets. The accuracy by deriving the dice similarity coefficient (DSC) value and the segmentation time for each learning step were compared. In addition, visual scoring was considered to comparatively evaluate the manual and automatic segmentation., Results: After learning, the DSC gradually increased to 0.48 ± 0.11 to 0.50 ± 0.11, and 0.58 ± 0.08. The DSC for the external dataset was 0.49 ± 0.12. The times required for segmentation were 124.8, 143.4, and 86.4 s, showing a large decrease at the final stage. In visual scoring, the accuracy of manual segmentation was found to be higher than that of automatic segmentation., Conclusions: The deep active learning framework can serve as a fast, accurate, and robust clinical tool for demarcating IAN location., (© 2021. The Author(s).)

Objective: To predict the hand-wrist maturation stages based on the cervical vertebrae (CV) images, and to analyse the accuracy of the proposed algorithms., Settings and Population: A total of 499 pairs of hand-wrist radiographs and lateral cephalograms of 455 orthodontic patients aged 6-18 years were used for developing the prediction model for hand-wrist skeletal maturation stages., Materials and Methods: The hand-wrist radiographs and the lateral cephalograms were collected from two university hospitals and a paediatric dental clinic. After identifying the 13 anatomic landmarks of the CV, the width-height ratio, width-perpendicular height ratio and concavity ratio of the CV were used as the morphometric features of the CV. Patients' chronological age and sex were also included as input data. The ground truth data were the Fishman SMI based on the hand-wrist radiographs. Three specialists determined the ground truth SMI. An ensemble machine learning methods were used to predict the Fishman SMI. Five-fold cross-validation was performed. The mean absolute error (MAE), round MAE and root mean square error (RMSE) values were used to assess the performance of the final ensemble model., Results: The final ensemble model consisted of eight machine learning models. The MAE, round MAE and RMSE were 0.90, 0.87 and 1.20, respectively., Conclusion: Prediction of hand-wrist SMI based on CV images is possible using machine learning methods. Chronological age and sex increased the prediction accuracy. An automated diagnosis of the skeletal maturation may aid as a decision-supporting tool for evaluating the optimal treatment timing for growing patients., (© 2021 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: This study used machine learning and population data for testing the associations of preterm birth with gastroesophageal reflux disease (GERD) and periodontitis., Methods: Retrospective cohort data came from Korea National Health Insurance Service claims data for all women who aged 25-40 years and gave births for the first time as singleton pregnancy during 2015-2017 (405,586 women). The dependent variable was preterm birth during 2015-2017 and the independent variables were GERD (coded as no vs. yes) for each of the years 2002-2014, periodontitis (coded as no vs. yes) for each of the years 2002-2014, age (year) in 2014, socioeconomic status in 2014 measured by an insurance fee, and region (city) (coded as no vs. yes) in 2014. Random forest variable importance was adopted for finding main predictors of preterm birth and testing its associations with GERD and periodontitis., Results: Based on random forest variable importance, main predictors of preterm birth during 2015-2017 were socioeconomic status in 2014, age in 2014, GERD for the years 2012, 2014, 2010, 2013, 2007 and 2009, region (city) in 2014 and GERD for the year 2006. The importance rankings of periodontitis were relatively low., Conclusion: Preterm birth has a stronger association with GERD than with periodontitis. For the prevention of preterm birth, preventive measures for GERD would be essential together with the improvement of socioeconomic status for pregnant women. Especially, it would be vital to promote active counseling for general GERD symptoms (neglected by pregnant women)., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2021 The Korean Academy of Medical Sciences.)

Aim: This study aimed to investigate the association between work patterns and periodontal disease., Materials and Methods: Data were collected from the Korea National Health and Nutrition Examination Survey between 2007 and 2012, and data from 22,508 subjects aged ≥19 years were included. An individual's work pattern was classified as either daytime or shift work. Sleep duration was categorized into three ranges: ≤5, 6-8, and ≥9 h/day. A multivariate logistic regression model was used to determine the adjusted odds ratio (OR) for CPI (Community Periodontal Index) ≥3. The CONTRAST statement was used to show the interaction effect of work patterns and sleep duration., Results: The adjusted OR of shift work was 2.168 (CI: 1.929-2.438, p < .0001). Participants who sleep ≤5 or ≥9 h/day showed ORs 0.735 and 0.663, respectively (p = .0181). Interaction effect analysis revealed that the work pattern had a strong influence on periodontal condition when combined with the sleep amount. Shift workers with ≤5 or ≥ 9 h of sleep showed significantly increased ORs for CPI ≥3 (2.1406 and 2.3251, respectively, p < .0001). The ORs for daytime workers were comparable to the original values (≤5: 0.7348, p = .0292; ≥9: 0.6633, p = .0428)., Conclusion: Altered sleep patterns caused by shift work have more influence on periodontal disease than sleep duration., (© 2021 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

This study aimed to elucidate whether the stability of an unsintered hydroxyapatite particles/poly- l -lactide (uHA/PLLA) system is comparable with that of titanium, according to different load-bearing areas of the mandible. The study included patients who underwent open reduction and internal fixation of the mandibular body, angle, or subcondylar fracture. The stability of uHA/PLLA systems was compared between the immediate and 6-month postoperative time points using three-dimensional cone-beam CT image analysis. The positional changes of each landmark were measured in three-dimensional (3D) coordinate systems using simulation software. Among 36 patients, there were more displacements of the landmarks between the immediate and 6-month postoperative time points after subcondylar fracture reduction than after body or angle fracture reductions. Strong upward displacements of the landmarks after subcondylar fracture reduction were found in the lateral pole [mean (SD) = 1.75 (3.16), p-value = 0.003] and medial pole [mean (SD) = 1.64 (2.50), p-value = 0.024], but not in the center. Subgroup analyses revealed similar unstable results in males on the condylar landmarks after subcondylar fracture reduction. There were tendencies for lateral displacement of the coronoid process in the body fracture group [mean (SD) = 0.8 (0.83)] and angle fracture group [mean (SD) = 0.75 (0.58)] postoperatively (p-value = 0.01). This study concluded that bioresorbable osteosynthesis can be recommended for body or angle fractures, while the indication for subcondylar fractures is less clear., Competing Interests: Declaration of Competing Interest There are no conflicts of interest for this study., (Copyright © 2021 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

The utilization of cell-manipulating techniques reveals information about biological behaviors suited to address a wide range of questions in the field of life sciences. Here, we introduced an on/off switchable physical stimuli technique that offers precise stimuli for reversible cell patterning to allow regulation of the future direction of adherent cellular behavior by leveraging enzymatically degradable alginate hydrogels with defined chemistry and topography. As a proof of concept, targeted muscle cells adherent to TCP exhibited a reshaped structure when the hydrogel-based physical stimuli were applied. This simple tool offers easy manipulation of adherent cells to reshape their morphology and to influence future direction depending on the characteristics of the hydrogel without limitations of time and space. The findings from this study are broadly applicable to investigations into the relationships between cells and physiological extracellular matrix environments as well as has potential to open new horizons for regenerative medicine with manipulated cells.

In porous titanium scaffolds manufactured via 3D printing, the differences in bone formation according to pore design and implantation period were studied. Titanium scaffolds with three types of different pore structures (Octadense, Gyroid, and Dode) were fabricated via 3D printing using the selective laser melting method. Mechanical properties of scaffolds were investigated. Prepared specimens were inserted into both femurs of nine rabbits and their clinical characteristics were observed. Three animals were sacrificed at the 2nd, 4th, and 6th weeks, and the differences in bone formation were radiologically and histologically analyzed. The percentage of new bone and surface density in the pore structure were observed to be approximately 25% and 8 mm 2 /mm 3 , respectively. There was no difference in the amount of newly formed bone according to the pore design at 2, 4, and 6 weeks. In addition, no differences in the amount of newly formed bone were observed with increasing time within the same pore design for all three designs. During the 6-week observation period, the proportion of new bones in the 3D-printed titanium scaffold was approximately 25%. Differences in bone formation according to the pore design or implantation period were not observed.

A mandibular continuity defect can be repaired using either a prosthetic device or autogenous bone. A titanium reconstruction plate can be used with a localized or vascularized flap over the defect of the mandible. Unfortunately, the plate may fail due to plate exposure, screw loosening, fracture, or infection, and will need to be removed. Plate exposure though the skin or mucosa is one of the main reasons for failure. In the present work, the authors introduced a lingually positioned reconstruction plate fabricated via three-dimensional printed bending support. This custom reconstruction plate can avoid plate re-exposure as well as reduce surgical errors and operation time.

Background and Human bone marrow-derived mesenchymal stem cells (BMSCs) are promising sources for cell-based regenerative therapy. The purpose of the present study was to elucidate the roles of age and sex on the cellular viability and osteogenic potential of BMSCs cultured in osteogenic media. Objectives: Human bone marrow-derived mesenchymal stem cells (BMSCs) are promising sources for cell-based regenerative therapy. The purpose of the present study was to elucidate the roles of age and sex on the cellular viability and osteogenic potential of BMSCs cultured in osteogenic media. Materials and Methods: No significant differences were found in the cell viability of human BMSCs cultured in osteogenic media among the different age groups. There were no significant differences in the expression of SSEA among the age groups or between males and females. There were no significant differences in the secretion of human VEGF between males and females. No significant differences in Runx2 or collagen I expression were noted by age or gender. Moreover, no significant differences were shown in osteogenesis by alizarin red staining. Results: The human BMSCs showed no age-related decreases in cellular viability or osteogenic differentiation potential.Conclusions: The human BMSCs showed no age-related decreases in cellular viability or osteogenic differentiation potential.

The aim of this study was to segment the maxillary sinus into the maxillary bone, air, and lesion, and to evaluate its accuracy by comparing and analyzing the results performed by the experts. We randomly selected 83 cases of deep active learning. Our active learning framework consists of three steps. This framework adds new volumes per step to improve the performance of the model with limited training datasets, while inferring automatically using the model trained in the previous step. We determined the effect of active learning on cone-beam computed tomography (CBCT) volumes of dental with our customized 3D nnU-Net in all three steps. The dice similarity coefficients (DSCs) at each stage of air were 0.920 ± 0.17, 0.925 ± 0.16, and 0.930 ± 0.16, respectively. The DSCs at each stage of the lesion were 0.770 ± 0.18, 0.750 ± 0.19, and 0.760 ± 0.18, respectively. The time consumed by the convolutional neural network (CNN) assisted and manually modified segmentation decreased by approximately 493.2 s for 30 scans in the second step, and by approximately 362.7 s for 76 scans in the last step. In conclusion, this study demonstrates that a deep active learning framework can alleviate annotation efforts and costs by efficiently training on limited CBCT datasets.

The aim of this study was to evaluate the three-dimensional reproducibility of the structured-light facial scanner according to the head position change. A mannequin head was used and angle of the mannequin's axis-orbital plane to the true horizontal plane was adjusted to +10, +5, 0, -5, and -10°. Facial scanning was conducted 30 times, respectively, and 150 3D images were obtained. Reoriented landmarks of each group were compared and analyzed. Reproducibility decreased as the distance from the facial center increased. Additionally, the landmarks below showed lower reproducibility and higher dispersion than landmarks above. These differences occurred mainly in the anteroposterior direction as opposed to other directions. Positive inclination of the head position showed superior reproducibility compared to a negative inclination. This study showed that reproducibility of a structured-light scanner could be varied depending on the head position. Inaccuracies of landmarks in the anteroposterior direction are greater than in other directions. This means that evaluations of the profile using a structured-light scanner should be made carefully. Therefore, the proper head position should be set to ensure the accuracy of the image.

Hydroxyapatite, an essential mineral in human bones composed mainly of calcium and phosphorus, is widely used to coat bone graft and implant surfaces for enhanced biocompatibility and bone formation. For a strong implant-bone bond, the bone-forming cells must not only adhere to the implant surface but also move to the surface requiring bone formation. However, strong adhesion tends to inhibit cell migration on the surface of hydroxyapatite. Herein, a cell migration highway pattern that can promote cell migration was prepared using a nanosecond laser on hydroxyapatite coating. The developed surface promoted bone-forming cell movement compared with the unpatterned hydroxyapatite surface, and the cell adhesion and movement speed could be controlled by adjusting the pattern width. Live-cell microscopy, cell tracking, and serum protein analysis revealed the fundamental principle of this phenomenon. These findings are applicable to hydroxyapatite-coated biomaterials and can be implemented easily by laser patterning without complicated processes. The cell migration highway can promote and control cell movement while maintaining the existing advantages of hydroxyapatite coatings. Furthermore, it can be applied to the surface treatment of not only implant materials directly bonded to bone but also various implanted biomaterials implanted that require cell movement control., (© 2021 The Authors.)

Background: Periodontitis is reported to be associated with preterm birth (spontaneous preterm labor and birth). Gastroesophageal reflux disease (GERD) is common during pregnancy and is expected to be related to periodontitis. However, little research has been done on the association among preterm birth, GERD and periodontitis. This study uses popular machine learning methods for analyzing preterm birth, GERD and periodontitis., Methods: Data came from Anam Hospital in Seoul, Korea, with 731 obstetric patients during January 5, 1995 - August 28, 2018. Six machine learning methods were applied and compared for the prediction of preterm birth. Variable importance, the effect of a variable on model performance, was used for identifying major determinants of preterm birth., Results: In terms of accuracy, the random forest (0.8681) was similar with logistic regression (0.8736). Based on variable importance from the random forest, major determinants of preterm birth are delivery and pregestational body mass indexes (BMI) (0.1426 and 0.1215), age (0.1211), parity (0.0868), predelivery systolic and diastolic blood pressure (0.0809 and 0.0763), twin (0.0476), education (0.0332) as well as infant sex (0.0331), prior preterm birth (0.0290), progesterone medication history (0.0279), upper gastrointestinal tract symptom (0.0274), GERD (0.0242), Helicobacter pylori (0.0151), region (0.0139), calcium-channel-blocker medication history (0.0135) and gestational diabetes mellitus (0.0130). Periodontitis ranked 22nd (0.0084)., Conclusion: GERD is more important than periodontitis for predicting and preventing preterm birth. For preventing preterm birth, preventive measures for hypertension, GERD and diabetes mellitus would be needed alongside the promotion of effective BMI management and appropriate progesterone and calcium-channel-blocker medications., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2020 The Korean Academy of Medical Sciences.)

Background and Aims: The association between coronary heart disease (CHD) caused by atherosclerosis and periodontitis has already been established. Peripheral arterial disease (PAD) is also caused by atherosclerosis, but the characteristics of the target artery and the disease are different from those of CHD. The aim of this study was to determine whether the risk of PAD was high in patients with periodontitis., Methods: For this study, we used data from the Korean National Health Insurance Service-Health Screening Cohort (NHIS-HEALS) database that were collected between January 2003 and December 2014. We compared the incidence of PAD between patients with periodontitis and a matched control group selected from among 514,832 people enrolled in the NHIS-HEALS database to confirm the increased incidence of PAD in patients with periodontitis., Results: The incidence per 1000 person-years was 2.40 in the patients with periodontitis and 2.08 in the matched controls. The hazard ratio (HR) of PAD in the periodontitis group compared with that in the matched group was 1.15 (95% confidence interval, 1.07-1.23). In the subgroup analysis, sex, age, smoking, and hypertension statistically modified the influence of periodontitis on PAD risk., Conclusions: Control of periodontitis is important in the prevention of PAD, in addition to correcting conventional risk factors such as diabetes mellitus, hypertension, dyslipidemia, and smoking., Competing Interests: Declaration of competing interest The authors declared they do not have anything to disclose regarding conflict of interest with respect to this manuscript., (Copyright © 2020 Elsevier B.V. All rights reserved.)

In this study, a deep learning-based method for developing an automated diagnostic support system that detects periodontal bone loss in the panoramic dental radiographs is proposed. The presented method called DeNTNet not only detects lesions but also provides the corresponding teeth numbers of the lesion according to dental federation notation. DeNTNet applies deep convolutional neural networks(CNNs) using transfer learning and clinical prior knowledge to overcome the morphological variation of the lesions and imbalanced training dataset. With 12,179 panoramic dental radiographs annotated by experienced dental clinicians, DeNTNet was trained, validated, and tested using 11,189, 190, and 800 panoramic dental radiographs, respectively. Each experimental model was subjected to comparative study to demonstrate the validity of each phase of the proposed method. When compared to the dental clinicians, DeNTNet achieved the F1 score of 0.75 on the test set, whereas the average performance of dental clinicians was 0.69.

Purpose: The recent development of bioresorbable bone plates and screws allows plates to be applied to the load-bearing regions of the mandible and to remain in place over time without the need for removal. We hypothesized that the stability of composite plates and screws forged from unsintered hydroxyapatite particles and poly-l-lactide (u-HA/PLLA) is comparable to that of standard titanium fixation systems for the reduction of fractures of load-bearing regions of the mandibular body., Materials and Methods: 40 patients underwent open reduction and internal fixation of the fractured mandibular body with either a titanium or u-HA/PLLA bone plate. Cone-beam CT images were obtained immediately postoperatively and at 6-month follow-up, and were analyzed for positional changes of the affected mandible., Results: There were no significant differences in the postoperative positional changes of reference points between the titanium and u-HA/PLLA miniplates, except for that for the coronoid process (p-value = 0.03). Multivariate regression analysis revealed no significant differences in spatial changes between the immediate postoperative and 6-month follow-up images, after adjusting for age and sex., Conclusion: The stability of bioresorbable u-HA/PLLA miniplates and screws was comparable to that of titanium miniplates and screws immediately postoperatively and at 6-month follow-up, following surgical reduction of fractures of load-bearing regions of the mandibular body. Bioresorbable osteosynthesis can be considered a viable alternative to titanium osteosynthesis., (Copyright © 2019 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Background: We evaluated the improvement of pain and the increase in mouth opening after temporomandibular joint arthrocentesis and the possible association with various factors such as previous splint treatment, medication, and diagnosis., Results: We studied 57 temporomandibular joint disorder patients who underwent arthrocentesis at Korea University Anam Hospital. These patients (24 males and 33 females, aged between 15 and 76 years) underwent arthrocentesis that was performed by one surgeon. The degree of mouth opening (assessed using the maximum mouth opening: MMO) and pain (assessed using the visual analog scale: VAS) were assessed pre- and post-arthrocentesis. The study also investigated whether treatment modalities other than arthrocentesis (medication and appliance therapy) were performed. Statistical analysis revealed that there was a significant difference in mouth opening and pain after temporomandibular joint arthrocentesis. Preoperative appliance therapy affected the results of arthrocentesis, but it was not statistically significant. With regard to pain relief, preoperative diagnosis did not show a significant difference. However, with regard to maximum mouth opening, patients with disc displacement without reduction with limited mouth opening (closed lock) showed the highest recovery (11.13 mm)., Conclusion: The average of MMO increase after arthrocentesis was 9.10 mm, and patients with disc displacement without reduction with locking (closed lock) showed most recovery in maximum mouth opening and it was statistically significant. The average pain relief of patients after arthrocentesis was 3.03 in the VAS scale, and patients using anterior repositioning splint (ARS) preoperatively showed the most pain relief., Competing Interests: Competing interestsThe authors declare that they have no competing interests., (© The Author(s). 2019.)

Background: Radioiodine therapy has been widely used for thyroid disease patients, but hyposalivation and xerostomia may occur in 10~30% of patients. Sialocentesis is a procedure that removes inflammatory substances in the salivary duct and expands the duct for the secretion and delivery of saliva. In this study, thyroid disease patients treated with radioactive iodine were selected among the patients with xerostomia who visited the hospital, and the effect of sialocentesis was compared and analyzed. And then, comparison between the radioiodine therapy-experienced group and the non-radioiodine therapy-experienced group was conducted., Results: In this study, we studied xerostomia patients who underwent radioiodine therapy due to thyroid diseases and who underwent sialocentesis at the Korea University Anam Hospital. Sialocentesis is conducted by one surgeon. The study also compares the clinical symptoms before and after the surgery. After the procedure, the discomfort due to xerostomia was reduced, and the symptom was improved effectively., Conclusions: The results of this study showed that sialocentesis has a clinical effect in the treatment of xerostomia, which is a side effect of radioiodine therapy. In addition, the possibility of further clinical application of sialocentesis in the future is found., Competing Interests: Competing interestsThe authors declare that they have no competing interests.

This study examined whether or not various mouthwashes have significant effects on the viability or morphology of mouse osteoblast-like cells. Mouse calvarial preosteoblast cells were cultured and prepared, then treated with a 0.12% chlorhexidine digluconate solution containing essential oils with or without alcohol, and a cetylpyridinium chloride solution, and sodium fluoride, respectively. Each well was treated with one of six mouthwashes for either 30 sec, 1.5 min, or 4.5 min. The viability of the treated cells was quantitatively analyzed by a Cell Counting Kit-8. The viability of osteogenic progenitor cells decreased significantly irrespectively of the types of mouthwashes. The changes of cell morphology were seen in all groups of mouthwashes; however, they were more noticeable on the chlorhexidine digluconate-treated group. A progressive increase in treatment time over 30 sec did not seem to deteriorate cellular viability. There was no significant difference in viability or morphological change between different formulations of the same brand. Although various mouthwashes without alcohol as an ingredient are available, nonalcoholic mouthwashes were not likely to be less harmful to the cells. Collectively, commercially available mouthwashes could inhibit cell viability and alter the morphology of osteoblastic precursor cells irrespectively of brands, treatment time, or alcohol content., Competing Interests: Conflict of interest: Authors state no conflict of interest, (© 2019 In-Seok Song et al., published by De Gruyter.)

Purpose: To evaluate the influence of low signal-to-noise ratio (SNR) of axial length measurement, achieved using IOLMaster, on prediction of target refraction., Methods: A total of 131 eyes of 131 patients who underwent phacoemulsification with posterior chamber lens implantation were enrolled. Preoperative axial length measurements were performed with the IOLMaster 500 (Carl Zeiss Meditec, Germany); preoperative SNR values were used to divide the eyes into three groups (Group 1; SNR <10, Group 2; 10 ≤ SNR <50, Group 3; 50 ≤ SNR <100). One month and 6 months after cataract surgery, the manifest refraction spherical equivalents (MRSE) were measured. The mean numeric errors (MNE), the mean of the difference between postoperative MRSE, and preoperative target refraction, using the various intraocular lens (IOL) formulas, were calculated and compared among the three groups., Results: One month after cataract surgery, postoperative MRSE was more hyperopic than preoperative target refraction, calculated by the Haigis formula in group 1, and by the SRK/T formula in group 2. After 6 months, for all formulas in group 1, there were significantly hyperopic results (approximately 0.35 diopter). Upon comparison of MNE among the three groups, group 1 was statistically significantly different from the other groups by Haigis formula., Conclusions: When the SNR values in biometry, using IOLMaster, are <10, careful attention should be given to determining IOL power, as postoperative spherical equivalents are more hyperopic than preoperative target refraction by IOL formula., Competing Interests: The authors have declared that no competing interests exist.

This study was performed to assess the relationship between menstrual irregularity and dental pain or chewing discomfort in women before menopause, using nationally representative data. This study analyzed 4595 participants who were ≥19 years or older, and did not have missing values for outcome variables from the Korean National Health and Nutrition Examination Survey. Tooth pain was considered present if the participant felt throbbing discomfort, pain, or sensitivity when eating hot or cold food or drinking hot or cold beverages. Self-reported oral chewing discomfort was obtained. Adjusted odds ratios and their 95% confidence intervals for tooth pain in the individuals with menstrual cycle irregularity were 1.30 (1.05, 1.62) after adjustment for age, body mass index, drinking, smoking, income, exercise, stress, metabolic syndrome, and the frequency of tooth brushing. Adjusted odds ratios and their 95% confidence intervals for chewing discomfort in the individuals with menstrual cycle irregularity were 1.33 (1.03, 1.72) after adjustment. The association between menstrual irregularity and dental pain or chewing discomfort in women before menopause was proven-after adjusting for confounding factors-by multiple logistic regression analyses. Menstrual cycle irregularity may be considered a potential risk indicator for dental pain or chewing discomfort in Korean women before menopause., Competing Interests: The authors declare no conflicts of interest.

The investigators hypothesized there would be differences between the sexes in recovery pattern following bimaxillary orthognathic surgery as measured by patient responses at 5 weeks postprocedure. A total of 378 participants underwent bimaxillary orthognathic surgery with or without adjunctive procedures. Participants received questionnaires 5 weeks postsurgery when they visited the outpatient clinic. The questionnaires include variances in surgical factors by sex, and postoperative symptoms which were most difficult to tolerate experiences by sex, respectively. Females were more likely to undergo malarplasty (zygoma reduction) than were male participants (P = <.001), and they required larger maxillary setback than did male participants (P = .003). Malarplasty was significantly correlated with ear fullness in total and female participants (p-value .018, .016, respectively). Snoring is significantly associated with malarplasty and segment osteotomy procedure without gender predominance (p-value = .026, .028, respectively). Over half of participants complained of nasal congestion (55.6%), followed by swelling (29.3%), pain (15.4%), breathing difficulty (10.6%). In conclusion, males and females showed different patterns of postoperative recovery following bimaxillary orthognathic surgery., (Copyright © 2018 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

[This corrects the article on p. 225 in vol. 44, PMID: 30402414.].

Objectives: The purpose of this study was to investigate the demographic and clinical characteristics of patients with medication-related osteonecrosis of the jaw (MRONJ) and to elucidate factors affecting recurrence in surgical treatment., Materials and Methods: A total of 51 patients who were diagnosed with MRONJ were analyzed according to demographic and clinical features and treatment results through a retrospective chart review from 2013 to 2017 in the Department of Oral and Maxillofacial Surgery, Korea University Anam Hospital, Seoul in Korea., Results: Alendronate composed the majority of medication doses (55.6%), followed by ibandronate (20.0%), risedronate (15.6%), and zoledronate (6.7%). Forty patients (88.9%) were given oral medication, and five patients (11.1%) were intravenously treated, and the mean duration of medication use was 61.1±42.9 months. A total of 10 patients (22.2%) had a drug holiday before MRONJ-induced dental treatment lasting an average of 6.8±7.0 months. MRONJ occurred 2.7 times more in the mandible, with 41 cases (73.2%) occurring in the mandible and 15 cases (26.8%) occurring in the maxilla, and the prevalence of affected posterior parts (premolar-molar) was six times greater than that of the anterior parts (incisor-canine) (48 cases vs 8 cases, 85.7% vs 14.3%). The most common dental cause of MRONJ was tooth extraction (69.6%). Regarding recurrence, there was no statistical difference in recurrence rate according to either site or stage. However, recurrence occurred in 4 out of 34 cases (11.8%) in the primary closure group and 9 out of 20 cases (45.0%) in the secondary healing group, and there was a statistical difference with respect to closure technique., Conclusion: The identified risk factors in patients taking bone resorption inhibitors can aid dental clinicians in ensuring prevention and proper treatment of MRONJ., Competing Interests: Conflict of Interest: No potential conflict of interest relevant to this article was reported.

Dental implants positioned in severely atrophied anterior maxillae require esthetic or functional compromises. This case report describes the rehabilitation of a severely atrophied alveolar ridge with a three-dimensional (3D) computer-aided design/computer-aided manufacture (CAD/CAM) surgical guide. A 50-year-old woman had a severely atrophied anterior maxilla with unfavorably positioned dental implants. Functional and esthetic prosthodontic restoration was difficult to achieve. An anterior segmental osteotomy was planned to reposition the dental implants. A 3D surgical guide was designed for precise relocation of the segment. The surgical guide firmly grasped the impression copings of the dental implants, minimizing surgical errors. Three-dimensional gingival simulation was used preoperatively to estimate the appropriate position of the gingiva. Rigid fixation to the surrounding bone allowed immobilization of the implant-bone segment. Satisfactory esthetic and functional outcomes were attained 6 months after surgery. Finally, a severely atrophied alveolar ridge with unfavorably positioned dental implants was recovered with minimal esthetic and functional deterioration using gingival simulation and a 3D CAD/CAM surgical guide.

The aim of this study was to examine the association between coffee intake and tooth loss. This study hypothesized that the intake of coffee would increase the prevalence of tooth loss in Korean adults. Subject information was obtained from the Korea National Health and Nutrition Examination Survey conducted in 2010-2011. Sociodemographic and lifestyle variables, anthropometric and biochemical status, metabolic health and glucose tolerance status, as well as oral health behaviors were evaluated. The number of remaining teeth was negatively associated with the frequency of coffee intake (p-value < 0.05). Daily coffee consumers had significantly higher levels of body mass index (BMI), waist circumference (WC), total cholesterol, and low density lipoprotein cholesterol (LDL-C) (all p-value < 0.05). Individuals with less than 20 remaining teeth had higher BMI, WC, diastolic blood pressure, and LDL-C (all p-value < 0.05). Finally, participants who drank coffee on a daily basis were more likely to have fewer remaining teeth. The prevalence of having less than 20 remaining teeth was 69% higher in groups with daily coffee intake than those with coffee intake of less than once a month after adjustment for potential covariates (Odds Ratio [95% CI] = 1.69 [1.35, 2.13]). In conclusion, daily coffee consumption is closely associated with tooth loss in Korean adults.

Background: A slender or slim face with narrow facial features is considered esthetically appealing in Asian people. Plastic surgery to obtain an oval face, called a 'V-line,' is popular among young people., Materials and Methods: A total of 20 Korean patients were included in this study. The patients underwent mandibular anguloplasty with three-dimensional computer-aided design and manufacturing surgical guides that were accurately fitted to the upper and lower teeth, allowing for precise replication of a virtual surgery during a real surgical procedure., Results: There were no significant complications, including severe bleeding, facial nerve injury, or airway obstruction. All patients were satisfied with the esthetic and functional results, except for one who was neutral toward the result. The mean satisfaction score was 4.75, which was between 'satisfied' and 'very satisfied.', Conclusion: The V-line guide and gooseneck saw allowed for safe and fast resection of bone in the mandibular angle area. This technique provides consistent results during surgery as well as minimizing surgical complications., Level of Evidence Iv: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors http://www.springer.com/00266 .

Bone morphogenetic protein 2 (BMP-2) has a critical function in bone and cartilage development and in repairing damaged organs and tissue. However, clinical use of BMP-2 at doses of 0.5-1 mg/ml for orthopedics has been associated with severe postoperative swelling requiring emergency surgical intervention. We determined whether a high concentration of BMP-2 induces inflammatory responses in macrophages and the suppression of osteogenesis in hMSCs. We obtained human periodontal ligament stem cells and bone marrow stem cells from the maxilla, i.e., human mesenchymal stem cells (hMSCs), from the periodontal ligament of extracted third molar teeth and from the bone marrow of the maxilla, respectively. Osteogenic differentiation was measured by alkaline phosphatase activity and alizarin red S staining. Proteins were assessed by flow cytometry, enzyme-linked immunosorbent assay, Western blot and immunocytochemistry. Changes of gene expression were measured by reverse transcription plus the polymerase chain reaction (RT-PCR) and real-time PCR. A high BMP-2 concentration inhibited the early stages of osteogenesis in hMSCs. Co-culturing THP-1 cells (human monocytic cells) with hMSCs reduced the late stages of osteogenesis compared with those seen in hMSCs alone. In addition, high-dose BMP-2 induced the expression of inflammatory cytokines in THP-1 cells and the expression of the anti-inflammatory cytokine tumor-necrosis-factor-α-inducible gene 6 protein (TSG-6) in hMSCs. Consistent with the anti-inflammatory effects of hMSCs when co-cultured with THP-1 cells, interleukin-1β expression was downregulated by TSG-6 treatment of THP-1 cells. Our findings suggest that a high BMP-2 concentration triggers inflammation that causes inflammatory cytokine release from THP-1 cells, leading to the suppression of osteogenesis, whereas TSG-6 secreted by hMSCs suppresses inflammatory reactions through p38 and ERK in the mitogen-activated protein kinase pathway.

There is growing interest in the relationship between body mass index and oral health. Previous study showed that being underweight was significantly associated with having lower masticatory performance. This study was performed to assess the relationship between an underweight body mass index lower than 18.5 and the number of natural teeth using nationally representative data. Initially, a total of 25,534 individuals were candidates in the Korean National Health and Nutrition Examination Survey. The analysis in this study was confined to 17,870 subjects who were 19 years or older and without missing values for outcome variables. Body mass index and number of natural teeth were evaluated. Multiple regression analysis was used to evaluate the risk of tooth loss in relation to body mass index. Adjusted odds ratios and their 95% confidence intervals for chewing discomfort in individuals who were underweight, normal, overweight, obese, and extremely obese were 1.712(1.156-2.535), 1.111(0.939-1.315), 1(reference), 0.949(0.798-1.128), and 1.172(0.807-1.700), respectively, after adjustment. The association between underweight and tooth loss was proven by multiple logistic regression analyses after adjusting for confounding factors. Underweight may be considered a potential risk indicator for tooth loss in Korean adults., Competing Interests: The authors declare no competing financial interests.