Dental implants are accepted as an effective treatment tools; however, they have a biomechanically disadvantageous structure compared with natural teeth. To compensate for the structural limitations of dental implants, occlusal must be considered to minimize the stress applied to the implants. This study aimed to verify whether the basic biomechanical principle that stress should be applied along the long axis of the implant fixture could be appropriately applied to actual implant clinical treatment. To evaluate whether the major axis of the implant is located at the center of the occlusion surface, the location of the screw hole was analyzed using the image of the stereolithographic file formed during the digital laboratory process, and the accuracy of implant placement was confirmed indirectly.The study included 261 patients and 392 implant cases. By tooth type, the numbers of samples were 57 in the first premolar, 66 in the second premolar, 152 in the first molar, and 117 in the second molar. The location of the screw hole was analyzed by dividing the occlusion surface of the implant crown into nine grids of the same size based on the outermost boundary. Consequently, the accuracy of implant placement tended to decrease from the premolar to the molar, upper jaw to the lower jaw, and left to right.

In recent years, treatment using implants has become common. Since 2016, dental implants have been insured as part of strengthening health insurance coverage. Consequently, the demand for implants is increasing. Accordingly, the importance of implant maintenance has been emphasized. Of which, implant retrievability is an important factor in implant success. Although the screw-retained type is an advantageous easy-to-retrieve prosthesis, an occlusal point cannot make it to the central axis of the implant. Thus, we aimed to introduce an implant setting method (screw hole indexing) that enables the maintenance of the proper occlusal point and enables retrievability by marking the screw holes of the implant.

Objectives: The purpose of this study was to develop a non-suicidal self-injury (NSSI) prevention program for adolescents and confirm its effectiveness in primary prevention by applying dialectical behavior therapy skills training (DBT-ST). Methods: From September to December 2021, 217 first-year students in three middle schools in the Chungcheong Province were tested for changes from before and after the program using the Responses to Depressed Mood Questionnaire and Difficulties in Emotion Regulation Scale-16 using paired t-tests. McNemar’s test was conducted to confirm the changes in the perception and attitude scale of NSSI for each question. Results: A comparison of the changes from before and after the program revealed that the response to depressed mood (t=7.93, p<0.001), ruminant response (t=5.18, p<0.001), and distractive response (t=6.07, p<0.001) which are subfactors of the response to depressive moods, were significantly affected. There was a significant decrease in the difficulty in performing goaloriented behavior (t=3.34, p=0.01) and lack of emotional clarity (t=2.52, p=0.012), which are subfactors of emotional regulation difficulties. Also, in the comparison of the perception and attitude towards NSSI, statistically significant changes were confirmed in 7 out of a total of 9 questions (p<0.001). Conclusion It was confirmed that this program developed by applying DBT-ST was effective in the primary prevention of NSSI for adolescents.

Background: The Omicron variant has become the most prevalent SARS-CoV-2 variant. Omicron is known to induce milder lesions compared to the original Wuhan strain. Fatal infection of the Wuhan strain into the brain has been well documented in COVID-19 mouse models and human COVID-19 cases, but apparent infections into the brain by Omicron have not been reported in human adult cases or animal models. In this study, we investigated whether Omicron could spread to the brain using K18-hACE2 mice susceptible to SARS-CoV-2 infection. Results: K18-hACE2 mice were intranasally infected with 1 × 105 PFU of the original Wuhan strain and the Omicron variant of SARS-CoV-2. A follow-up was conducted 7 days post infection. All Wuhan-infected mice showed > 20% body weight loss, defined as the lethal condition, whereas two out of five Omicron-infected mice (40%) lost > 20% body weight. Histopathological analysis based on H&E staining revealed inflammatory responses in the brains of these two Omicron-infected mice. Immunostaining analysis of viral nucleocapsid protein revealed severe infection of neuron cells in the brains of these two Omicron-infected mice. Lymphoid depletion and apoptosis were observed in the spleen of Omicron-infected mice with brain infection. Conclusion Lethal conditions, such as severe body weight loss and encephalopathy, can occur in Omicron-infected K18-hACE2 mice. Our study reports, for the first time, that Omicron can induce brain infection with lymphoid depletion in the mouse COVID-19 model.

Attrition is the loss of tooth hard tissue due to contact between teeth, and in severe cases, dentin is exposed, accompanied by selective corrosion and excessive wear of teeth, which is called cupping. If these lesions are left untreated, the size of the lesion gradually increases, breaking the unsupported enamel, resulting in a decrease in aesthetics and chewing function. In this case report, patients with cupping and enamel fracture due to severe attrition were directly restored using a resin with soft properties containing organic fillers. In the follow-up observation six years later, most of the filling of the occlusal surface was eliminated, but the filling on the buccal surfaces remained relatively intact, and it was confirmed that this type of resin was suitable for the area where the occlusal force was relatively weak rather than the area where the occlusal force was greatly applied.

Maxillary bone defects may follow surgical treatment of benign and malignant tumors, trauma, and infection. Palatal defects often lead to problems with swallowing and pronunciation from the leakage of air into the nasal cavity and sinus. Obturators have been commonly used to solve these problems, but long-term use of the device may cause irritation of the oral mucosa or damage to the abutment teeth. Utilizing implants in the edentulous area for the fabrication of the obturators has gained attention. This case report describes a patient, who had undergone partial resection of the maxilla due to adenocarcinoma, in need of a new obturator after losing abutment teeth after long-term use of the previous obturator. Implants were placed in strategic locations, and an implantretained maxillary obturator was fabricated, showing satisfactory results in the rehabilitation of multiple aspects, including palatal defect, masticatory function, swallowing, pronunciation, and aesthetics.

Purpose: This study aimed to examine the relationships between participative decision-making, psychological empowerment, and organizational citizenship behavior of nurses working in hospitals; moreover, we verified the moderated mediating effect of power distance orientation in these relationships. Methods: A total of 201 nurses working at a university hospital in South Korea responded to the survey. Self-report surveys were used to gather data from July 15-August 15, 2021. SPSS 22.0, AMOS 22.0, and SPSS PROCESS macro were used for data analysis. Results: Psychological empowerment significantly mediated the relationship between participative decision making and organizational citizenship behavior. Moreover, the moderating effect of power distance orientation on the relationship between participative decision making and psychological empowerment was also significant when the power distance orientation was at a low and average levels. However, the moderated mediating effect of power distance orientation on the relationship between participative decision making, psychological empowerment, and organizational citizenship behavior was insignificant. Conclusion Involving nurses with lower power distance orientation in decision making is crucial to elicit positive work performance and different strategies are necessary for those with higher power distance orientation. Finally, further studies are needed to understand the power distance orientation and positive work outcomes of nurses.

Background: and Purpose Previous studies have assessed the relationship between cerebral vessel tortuosity and intracranial aneurysm (IA) based on two-dimensional brain image analysis. We evaluated the relationship between cerebral vessel tortuosity and IA according to the hemodynamic location using three-dimensional (3D) analysis and studied the effect of tortuosity on the recurrence of treated IA. Methods: We collected clinical and imaging data from patients with IA and disease-free controls. IAs were categorized into outer curvature and bifurcation types. Computerized analysis of the images provided information on the length of the arterial segment and tortuosity of the cerebral arteries in 3D space. Results: Data from 95 patients with IA and 95 controls were analyzed. Regarding parent vessel tortuosity index (TI; P<0.01), average TI (P<0.01), basilar artery (BA; P=0.02), left posterior cerebral artery (P=0.03), both vertebral arteries (VAs; P<0.01), and right internal carotid artery (P<0.01), there was a significant difference only in the outer curvature type compared with the control group. The outer curvature type was analyzed, and the occurrence of an IA was associated with increased TI of the parent vessel, average, BA, right middle cerebral artery, and both VAs in the logistic regression analysis. However, in all aneurysm cases, recanalization of the treated aneurysm was inversely associated with increased TI of the parent vessels. Conclusions TIs of intracranial arteries are associated with the occurrence of IA, especially in the outer curvature type. IAs with a high TI in the parent vessel showed good outcomes with endovascular treatment.

Background: and Purpose Previous studies have assessed the relationship between cerebral vessel tortuosity and intracranial aneurysm (IA) based on two-dimensional brain image analysis. We evaluated the relationship between cerebral vessel tortuosity and IA according to the hemodynamic location using three-dimensional (3D) analysis and studied the effect of tortuosity on the recurrence of treated IA. Methods: We collected clinical and imaging data from patients with IA and disease-free controls. IAs were categorized into outer curvature and bifurcation types. Computerized analysis of the images provided information on the length of the arterial segment and tortuosity of the cerebral arteries in 3D space. Results: Data from 95 patients with IA and 95 controls were analyzed. Regarding parent vessel tortuosity index (TI; P<0.01), average TI (P<0.01), basilar artery (BA; P=0.02), left posterior cerebral artery (P=0.03), both vertebral arteries (VAs; P<0.01), and right internal carotid artery (P<0.01), there was a significant difference only in the outer curvature type compared with the control group. The outer curvature type was analyzed, and the occurrence of an IA was associated with increased TI of the parent vessel, average, BA, right middle cerebral artery, and both VAs in the logistic regression analysis. However, in all aneurysm cases, recanalization of the treated aneurysm was inversely associated with increased TI of the parent vessels. Conclusions TIs of intracranial arteries are associated with the occurrence of IA, especially in the outer curvature type. IAs with a high TI in the parent vessel showed good outcomes with endovascular treatment.