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Early life stress (ELS) in developing children has been linked to physical and psychological sequelae in adulthood. In the present study, we investigated the effects of ELS on brain and behavioral development by establishing a novel ELS model that combined the maternal separation paradigm and mesh platform condition. We found that the novel ELS model caused anxiety- and depression-like behaviors and induced social deficits and memory impairment in the offspring of mice. In particular, the novel ELS model induced more enhanced depression-like behavior and memory impairment than the maternal separation model, which is the established ELS model. Furthermore, the novel ELS caused upregulation of arginine vasopressin expression and downregulation of GABAergic interneuron markers, such as parvalbumin (PV), vasoactive intestinal peptide, and calbindin-D28k (CaBP-28k), in the brains of the mice. Finally, the offspring in the novel ELS model showed a decreased number of cortical PV-, CaBP-28k-positive cells and an increased number of cortical ionized calcium-binding adaptors-positive cells in their brains compared to mice in the established ELS model. Collectively, these results indicated that the novel ELS model induced more negative effects on brain and behavioral development than the established ELS model.

Background Clinical benefits of local antibiotics as an adjunct to nonsurgical treatment of peri-implantitis have been widely reported, but most studies evaluated incipient peri-implantitis lesions, and showed incomplete treatment success rates. Purpose To assess the clinical and microbiological outcomes of administering metronidazole in combination with minocycline as a local adjunct to the nonsurgical treatment of peri-implantitis. Materials and methods One hundred and eighteen subjects with peri-implantitis were recruited in a four-center, three-arm, and 12-week randomized controlled trial. Subjects were randomly assigned to receive one of the following treatments: (a) MM-mechanical debridement + metronidazole-minocycline ointment, (b) MC-mechanical debridement + minocycline ointment, (c) NST-mechanical debridement only. Results Except for four subjects who was excluded during the trial, a total of 114 patients with 114 implants (one implant per each patient) finally completed the trial and were included in the analyses. Multivariate logistic regression analysis revealed that the treatment success rates (absence of bleeding or suppuration on probing, and sites showing pocket probing depth [PPD] ≥5 mm) on at 12 weeks were higher in MM-group patients (31.6%) and MC-group patients (20.5%) compared to NST-group patients (2.7%; p = 0.011 and 0.040, respectively). Subjects with deepest PPD ≥8 mm showed a significant difference in the PPD reduction between MM and MC groups at week 4 (p = 0.025) and week 12 (p = 0.047). Detection ratio of Tannerella forsythia was significantly lower for MM group than MC group (p = 0.038). Conclusions Additive use of either MM or MC results in significantly higher treatment success rates compared to sole mechanical debridement in nonsurgical treatment of peri-implantitis. Moreover, MM contributes to a significantly greater reduction in the PPD compared to MC in deep pockets (cris.nih.go.kr KCT0004557).

The Middle East Respiratory Syndrome (MERS-CoV) is a potentially fatal respiratory viral infection that has had outbreaks in the Middle East and Asia region starting in 2012. As recent as 2015, MERS had outbreaks in South Korea, resulting in 36 deaths among 186 infected patients. The purpose of this thesis is to gain an in-depth understanding of how this viral infection behaves in outbreaks and how it is spread around the globe. To gain insight, real time analysis was performed under a case study methodology based on pooled data from the Ministry of Health & Welfare of South Korea. We calculated a striated mortality rate based on gender, age, and the presence of pre-existing health conditions ranging from heart, lung, and kidney diseases. We found that MERS outbreak follows the pattern of a point source outbreak, largely spurred by the patient-referral system under the universal healthcare system in South Korea. The purpose of this case is to discuss the benefits and challenges of such patient referral system, and to offer a possible solution in improving transparency between healthcare providers and the government under a universal healthcare system to prevent future outbreaks.

Purpose The aim of this retrospective study was to determine the prevalence of early implant failure using a single implant system and to identify the factors contributing to early implant failure. Methods Patients who received implant treatment with a single implant system (Luna®, Shinhung, Seoul, Korea) at Dankook University Dental Hospital from 2015 to 2017 were enrolled. The following data were collected for analysis: sex and age of the patient, seniority of the surgeon, diameter and length of the implant, position in the dental arch, access approach for sinus-floor elevation, and type of guided bone regeneration (GBR) procedure. The effect of each predictor was evaluated using the crude hazard ratio and the adjusted hazard ratio (aHR) in univariate and multivariate Cox regression analyses, respectively. Results This study analyzed 1,031 implants in 409 patients, who comprised 169 females and 240 males with a median age of 54 years (interquartile range [IQR], 47–61 years) and were followed up for a median of 7.2 months (IQR, 5.6–9.9 months) after implant placement. Thirty-five implants were removed prior to final prosthesis delivery, and the cumulative survival rate in the early phase at the implant level was 95.6%. Multivariate regression analysis revealed that seniority of the surgeon (residents: aHR=2.86; 95% confidence interval [CI], 1.37–5.94) and the jaw in which the implant was placed (mandible: aHR=2.31; 95% CI, 1.12–4.76) exerted statistically significant effects on early implant failure after adjusting for sex, age, dimensions of the implant, and type of GBR procedure (preoperative and/or simultaneous) (P, Graphical Abstract

Background To evaluate gingival inflammation from fixed-dose combinations of vitamin C, vitamin E, lysozyme and carbazochrome (CELC) in the treatment of chronic periodontitis following scaling and root planing. Methods One hundred patients were randomly assigned to receive CELC (test) or placebo (control) for the first 4 weeks at a 1:1 ratio, and both groups received CELC for the remaining 4 weeks. Primary outcome was the mean change in the gingival index (GI) after 4 weeks. Secondary outcomes included mean change in GI after 8 weeks and plaque index, probing depth, clinical attachment level, and VAS at 4 weeks and 8 weeks. Results Ninety-three patients completed the study. The GI in the test group significantly decreased after 4 weeks (p

The aim of the present study was to re-visit the gingival dimension using digital scanning in a healthy Korean population. Forty-eight periodontally healthy volunteers (38 males and 10 females, mean age: 24.3 ± 2.2 years) were included. The mucogingival junction was highlighted using 2.5% diluted iodine solution. Then, the facial gingiva and mucosa of both jaws were digitally scanned using an intraoral digital scanner. Using computer software and periodontal probing, the heights and areas of keratinized gingiva (KG) and attached gingiva (AG) were measured. Similar distribution patterns in the gingival heights were noted in the maxilla and mandible. The maxilla showed substantially greater gingival values than the mandible. The heights of the KG and AG were notably smaller on the mandibular first premolar (2.37 mm and 1.07 mm, median value) and second molar (3.28 mm and 1.78 mm) than on the other teeth. The area of the KG was the largest in the canine (63.74 mm2 and 46.85 mm2) and first molar (64.14 mm2 and 58.82 mm2) in each jaw. Mandibular first and second molars, mandibular canine, and maxillary canine showed the highest value of the area under the receiver operation characteristics curve (&gt, 0.7) for differentiating between males and females. The gingival dimensions recorded using intraoral scanner demonstrated similar distribution patterns as in previous studies.

Lactococcus lactis is a probiotic bacterium that produces various bacteriocins. Periodontopathogens induce inflammation and halitosis through the actions of lipopolysaccharide (LPS) and trypsin-like enzymes. The purpose of this study was to investigate the inhibitory effects of L. lactis on the bioactivity of periodontopathogens. To investigate the antimicrobial peptide of L. lactis, the spent culture medium (SCM) of L. lactis was treated with or without proteinase K after collection by centrifugation, and the antibacterial activity of SCM against periodontopathogens was assessed. To evaluate the neutralizing effect of L. lactis on halitosis, SCM of periodontopathogens was mixed with an L. lactis suspension, and the levels of volatile sulfur compounds (VSCs) were measured by gas chromatography. LPS from the periodontopathogens was extracted by an LPS extraction kit with little modification, and THP-1 cells as a monocytic cell line were treated with the extracted LPS in the presence or absence of UV-killed L. lactis. The production of inflammatory cytokines was analyzed by ELISA. The SCM of L. lactis exhibited antimicrobial activity against the periodontopathogens, whereas the proteinase K-treated SCM showed little antimicrobial activity. In addition, the L. lactis suspension had a neutralizing effect on the VSCs produced by periodontopathogens, and UV-killed L. lactis inhibited the production of IL-6 and TNF-α induced by the LPS. These results suggest that L. lactis may be a useful probiotic to prevent and treat periodontitis and halitosis.

Purpose The aim of this prospective pilot study was to compare alveolar ridge preservation (ARP) procedures with open-healing approach using a single-layer and a double-layer coverage with collagen membranes using radiographic and clinical analyses. Methods Eleven molars from 9 healthy patients requiring extraction of the maxillary or mandibular posterior teeth were included and allocated into 2 groups. After tooth extraction, deproteinized bovine bone mineral mixed with 10% collagen was grafted into the socket and covered either with a double-layer of resorbable non-cross-linked collagen membranes (DL group, n=6) or with a single-layer (SL group, n=5). Primary closure was not obtained. Cone-beam computed tomography images were taken immediately after the ARP procedure and after a healing period of 4 months before implant placement. Radiographic measurements were made of the width and height changes of the alveolar ridge. Results All sites healed without any complications, and dental implants were placed at all operated sites with acceptable initial stability. The measurements showed that the reductions in width at the level 1 mm apical from the alveolar crest (including the bone graft) were −1.7±0.5 mm in the SL group and −1.8±0.4 mm in the DL group, and the horizontal changes in the other areas were also similar in the DL and SL groups. The reductions in height were also comparable between groups. Conclusions Within the limitations of this study, single-layer and double-layer coverage with collagen membranes after ARP failed to show substantial differences in the preservation of horizontal or vertical dimensions or in clinical healing. Thus, both approaches seem to be suitable for open-healing ridge preservation procedures., Graphical Abstract

목적: 아라키돈산 대사물의 생합성을 억제하는 비스테로이드성 항염증제는 잠재적인 숙주조절제로 고려되고 있다. 이종설의 목적은 비스테로이드성 항염증제를 비외과적 치주치료와 병용하였을 때 치주질환자에 미치는 영향을 평가하는 데 있다. 연구 재료 및 방법: 관련된 연구를 확인하기 위하여 세 전자 데이터베이스를 ...

AIM To determine the effect of alveolar ridge preservation (ARP) in molar sites without primary flap closure. MATERIALS AND METHODS Three groups were established: extraction sockets grafted with deproteinized bovine bone mineral containing 10% collagen (DBBM-C) and covered by a native bilayer collagen membrane (NBCM) (test group 1), sockets grafted with DBBM-C only (test group 2), and sockets that healed naturally (control group). Primary flap closure was not attempted. Conebeam computed tomography scans were obtained immediately and then 4 months after ARP. A biopsy was performed. The change of the marginal bone level was measured. RESULTS There was significantly less horizontal resorption in test group 1 than in the control group at levels 1 mm (-1.02 ± 0.88 [mean ± SD] vs. -4.44 ± 3.71 mm) and 3 mm (-0.31 ± 1.51 vs. -2.27 ± 1.15 mm) below the crest, and significantly less vertical reduction in the midcrestal area in test group 1 than in test group 2 (-0.25 ± 0.95 vs. -1.15 ± 1.63 mm) (p

Lactococcus lactis is a probiotic bacterium that produces various bacteriocins. Periodontopathogens induce inflammation and halitosis through the actions of lipopolysaccharide (LPS) and trypsin-like enzymes. The purpose of this study was to investigate the inhibitory effects of L. lactis on the bioactivity of periodontopathogens. To investigate the antimicrobial peptide of L. lactis, the spent culture medium (SCM) of L. lactis was treated with or without proteinase K after collection by centrifugation, and the antibacterial activity of SCM against periodontopathogens was assessed. To evaluate the neutralizing effect of L. lactis on halitosis, SCM of periodontopathogens was mixed with an L. lactis suspension, and the levels of volatile sulfur compounds (VSCs) were measured by gas chromatography. LPS from the periodontopathogens was extracted by an LPS extraction kit with little modification, and THP-1 cells as a monocytic cell line were treated with the extracted LPS in the presence or absence of UV-killed L. lactis. The production of inflammatory cytokines was analyzed by ELISA. The SCM of L. lactis exhibited antimicrobial activity against the periodontopathogens, whereas the proteinase K-treated SCM showed little antimicrobial activity. In addition, the L. lactis suspension had a neutralizing effect on the VSCs produced by periodontopathogens, and UV-killed L. lactis inhibited the production of IL-6 and TNF-α induced by the LPS. These results suggest that L. lactis may be a useful probiotic to prevent and treat periodontitis and halitosis.

Purpose: The aims of this study are to analyze and to visualize distribution of patients visiting at a dental college hospital, using geographic information system (GIS). The visualized data can be utilized in patient care and treatment planning, ultimately leading to the assessment of risk evaluation and prevention of dental diseases. Materials and Methods: Patient information data was obtained from Dankook University Dental Hospital including the unit number, gender, date of birth, and address from 2007 to 2014. Patient distribution was visualized using GIS. Statistical analyses were performed using SAS 9.3 and ArcGIS 10.1. Five factors including proximity, accessibility, age, gender, and socioeconomic status were investigated as the explanatory variables of the patient distribution. Results: The visualized patient data showed a nationwide scale of the patient distribution. There was a little difference in characteristics for each department. As closer at Dankook University Dental Hospital, visitors increased. And it strongly showed that elderly patients in rural areas tend to visit more. Conclusion: The distribution of patients has been shown to be significantly affected by the proximity, accessibility, age, gender and socioeconomic status. The underlying reason remains to be further studied.

Purpose: Recently, smoking cessation treatment at dental clinic can be covered by national health insurance. The aim of this study is to evaluate the awareness on the health insurance coverage for smoking cessation treatment in dentistry. Materials and Methods: The survey was carried out on 100 new patients of the patients in Dankook Dental Hospital from March to April 2015. The Questionnaire consists of 18 items. Results: The results show that many of patients expect positive effects of the treatment but most of the respondents were not aware of the initiation of health insurance coverage smoking cessation treatment in dentistry. Conclusion: The government and ministry of health should pay more attention to the promotion of the smoking cessation treatment in dentistry. (J Dent Rehabil Appl Sci 2015;31(3):195-202)

Although there are a number of studies on the treatment planning and the prognosis of dental implants, limited studies provide the information on the implant placement on growing adolescents. The aim of this review is to discuss the use of dental implants in growing patients and the impact of skeletal and dentoalveolar growth on the long-term stability of implants. The general information regarding skeletal growth of maxilla and mandible would be briefly reviewed and the general treatment options would be discussed.

Purpose Following tooth extraction, alveolar ridge preservation (ARP) can maintain the dimensions of ridge height and width. Although previous studies have demonstrated the effects of ARP, few if any studies have investigated the compressive force applied during grafting. The aim of this study was to determine the effects of different compressive forces on the graft materials during ARP. Methods After tooth extraction, sockets were filled with deproteinized bovine bone mineral with 10% porcine collagen and covered by a resorbable collagen membrane in a double-layered fashion. The graft materials were compressed using a force of 5 N in the test group (n=12) and a force of 30 N in the control group (n=12). A hidden X suture was performed to secure the graft without primary closure. Cone-beam computed tomography (CBCT) was performed immediately after grafting and 4 months later, just before implant surgery. Tissue samples were retrieved using a trephine bur from the grafted sites during implant surgery for histologic and histomorphometric evaluations. Periotest values (PTVs) were measured to assess the initial stability of the dental implants. Results Four patients dropped out from the control group and 20 patients finished the study. Both groups healed without any complications. The CBCT measurements showed that the ridge volume was comparably preserved vertically and horizontally in both groups (P>0.05). Histomorphometric analysis demonstrated that the ratio of new bone formation was significantly greater in the test group (P0.05). Conclusions The application of a greater compressive force on biomaterials during ARP significantly enhanced new bone formation while preserving the horizontal and vertical dimensions of the alveolar ridge. Further studies are required to identity the optimal compressive force for ARP., Graphical Abstract

Purpose The preferred material for bone augmentation beyond the envelope of skeletal bone is the bone block graft, due to its dimensional stability. We evaluated the necessity of rigid fixation for the bone block graft, and compared the bone regeneration and volume maintenance associated with grafting using a synthetic hydroxyapatite block (HAB) and an autogenous bone block (ABB) without rigid fixation on rabbit calvaria over two different periods. Methods Cylinder-shaped synthetic HAB and ABB were positioned without fixation on the rabbit calvarium (n=16). The animals were sacrificed at 4 or 8 weeks postoperatively, and the grafted materials were analyzed at each healing period using microcomputed tomography and histologic evaluation. Results Integration of the graft and the recipient bed was observed in all specimens, although minor dislocation of the graft materials from the original position was evident in some specimens (six ABB and ten HAB samples). A tendency toward progressive bone resorption was observed in the grafted ABB but not in the grafted HAB, which maintained an intact appearance. In the HAB group, the area of new bone increased between 4 and 8 weeks postoperatively, but the difference was not statistically significant. Conclusions The nonfixed HAB was successfully integrated into the recipient bed after both healing periods in the rabbit calvaria. In spite of limited bone formation activity in comparison to ABB, HAB may be a favorable substitute osteoconductive bone material. Graphical Abstract

Purpose The aim of this study was to evaluate the transfer of different occlusal forces in various skeletal malocclusions using finite element analysis (FEA). Methods Three representative human cone-beam computed tomography (CBCT) images of three skeletal malocclusions were obtained from the Department of Orthodontics, Yonsei University Dental Hospital, Seoul, South Korea. The CBCT scans were read into the visualization software after separating bones and muscles by uploading the CBCT images into Mimics (Materialise). Two separate three-dimensional (3D) files were exported to visualize the solid morphology of skeletal outlines without considering the inner structures. Individual dental impressions were taken and stone models were scanned with a 3D scanner. These images were integrated and occlusal motions were simulated. Displacement and Von Mises stress were measured at the nodes of the FEA models. The displacement and stress distribution were analyzed. FEA was performed to obtain the 3D deformation of the mandibles under loads of 100, 150, 200, and 225 kg. Results The distortion in all three skeletal malocclusions was comparable. Greater forces resulted in observing more distortion in FEA. Conclusions Further studies are warranted to fully evaluate the impact of skeletal malocclusion on masticatory performance using information on muscle attachment and 3D temporomandibular joint movements. Graphical Abstract

Purpose: The aim of this study was to analyze the results of children treated with hemodialysis (HD) at Severance Hospital over 35 years in terms of incidence, etiologies, characteristics, complications, and clinical outcomes. Materials and Methods: We analyzed 46 children admitted to Severance Hospital who had undergone HD between January 1979 and December 2013. Results: The main etiologies of the 23 end-stage renal disease (ESRD) patients who had received HD were chronic glomerulonephritis (7 patients, 30.4%) and congenital anomalies of the kidney and urinary tract (7 patients, 30.4%), whereas the etiology of the 23 acute kidney injury (AKI) patients was hemolytic uremic syndrome (6 patients, 26.1%). Compared with ESRD patients, hemocatheter placement in the femoral vein was preferred over the subclavian or internal jugular vein in the AKI patients (p=0.012). The most common complication was catheter related complication (10 patients, 21.7%). The site of hemocatheter insertion was not related to the frequency of oozing. Placing the hemocatheter in the femoral vein resulted in significantly more events of cathe ter obstruction than insertion in the internal jugular vein or the subclavian vein (p=0.001). Disequilibrium syndrome occurred more frequently in older patients (p=0.004), as well as patients with a greater body weight (p=0.008) and a higher systolic and diastolic blood pressure before HD (systolic: p=0.021; diastolic: p=0.040). Conclusion: Based on the 35 years of experience in our center, HD can be sufficiently and safely carried out even in children without significant complications.