• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.31 no.5
• /
• pp.386-393
• /
• 2009

Objectives: This study was performed to evaluate course of the inferior alveolar canal in the mandibular ramus and to find safety zone when ramal bone is harvested. Patients and Methods: From January, 2009 to February, 2009, the 20 patients who visited in the Department of Oral and Maxillofacial Surgery, Sanbon Dental Hospital. Wonkwang University and the Conebeam CT was taken of various chief complaints, were selected. The patients who had left and right mandibular first molar and incisor missing, jaw fracture and bone pathology were excluded. The R point was defined as the point which occlusal plane was crossed to the mandibular anterior ramus(external oblique ridge). In the cross-sectional coronal and axial views, the inferior alveolar canal position to the R point, buccal bone width(BW), alveolar crest distance(ACD), distance from alveolar crest to occlusal plane(COD) and inferior alveolar canal to sagittal plane(CS) were measured and horizontal distance(HD), vertical distance(VD) and nearest distance(ND) were measured. Results: The inferior alveolar canal is located $6.19{\pm}1.21\;mm$ from the R point. Horizontal distance from the R point were $13.07{\pm}2.45\;mm$, vertical distance from the R point were $14.24{\pm}2.41\;mm$ and nearest distance from the R point were $10.12{\pm}1.76\;mm$. The course of the inferior alveolar canal was positioned within $0.61{\pm}0.68\;mm$. The distance from external buccal bone to the inferior alveolar canal was increased from the R point anteriorly. Conclusions: It is considered that the mandibular ramus from the R point to 10 mm anteriorly can be harvested safely at ramal bone grafting.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.40
• /
• pp.44.1-44.17
• /
• 2018

Background: Coffee extract has been investigated by many authors, and many minor components of coffee are known, such as polyphenols, diterpenes (kahweol and cafestol), melanoidins, and trigonelline, to have anti-inflammatory, anti-oxidant, anti-angiogenic, anticancer, chemoprotective, and hepatoprotective effects. Therefore, it is necessary to know its pharmacological effect on hepatocytes which show the most active cellular regeneration in body. Methods: In order to determine whether coffee extract has a beneficial effect on the liver, 20 C57BL/6J mice were intraperitoneally injected once with dialyzed coffee extract (DCE)-2.5 (equivalent to 2.5 cups of coffee a day in man), DCE-5, or DCE-10, or normal saline (control), and then followed by histological observation and IP-HPLC (immunoprecipitation high performance liquid chromatography) over 24 h. Results: Mice treated with DCE-2.5 or DCE-5 showed markedly hypertrophic hepatocytes with eosinophilic cytoplasms, while those treated with DCE-10 showed slightly hypertrophic hepatocytes, which were well aligned in hepatic cords with increased sinusoidal spaces. DCE induced the upregulations of cellular proliferation, growth factor/RAS signaling, cellular protection, p53-mediated apoptosis, angiogenesis, and antioxidant and protection-related proteins, and the downregulations of NFkB signaling proteins, inflammatory proteins, and oncogenic proteins in mouse livers. These protein expression changes induced by DCE were usually limited to the range ± 10%, suggesting murine hepatocytes were safely reactive to DCE within the threshold of physiological homeostasis. DCE-2.5 and DCE-5 induced relatively mild dose-dependent changes in protein expressions for cellular regeneration and de novo angiogenesis as compared with non-treated controls, whereas DCE-10 induced fluctuations in protein expressions. Conclusion: These observations suggested that DCE-2.5 and DCE-5 were safer and more beneficial to murine hepatocytes than DCE-10. It was also found that murine hepatocytes treated with DCE showed mild p53-mediated apoptosis, followed by cellular proliferation and growth devoid of fibrosis signaling (as determined by IP-HPLC), and subsequently progressed to rapid cellular regeneration and wound healing in the absence of any inflammatory reaction based on histologic observations.

• Anatomy & Biological Anthropology
• /
• v.27 no.3
• /
• pp.155-163
• /
• 2014

This study aimed to investigate the cusp size and morphological characteristics of permanent mandibular molars in Koreans with reference to the hypoconulid, and to analyze the differences and correlations between both sexes as well as between first and second mandibular molars. We obtained data from dental casts of 110 adults (78 males and 32 females). Mesiodistal and buccolingual diameters of first and second mandibular molars, the area of five cusps (protoconid, metaconid, hypoconid, entoconid, and hypoconulid), as well as the total cusp area and occlusal table area were measured. Paired t-test was performed to analyze the morphological differences between first and second mandibular molars and the sex differences between both sexes using SPSS program. Crown diameters and cusp areas of mandibular first molars were larger than those of mandibular second molars in both sexes. The hypoconulid was the most variable in size and morphological pattern among the five cusps, and the first molars showed a higher incidence of hypoconulid than the second molars. Except for the entoconid area of the first molar (p=0.06) and the hypoconulid area of the second molar (p=0.24), all other mean values were larger in males than in females, demonstrating a significant sexual dimorphism. These data suggest that the teeth which develop late in ontogeny tend to be smaller in size and more variable in morphological characteristics.

• Journal of Preventive Medicine and Public Health
• /
• v.52 no.6
• /
• pp.345-354
• /
• 2019

Objectives: It is well-known that post-traumatic stress disorder (PTSD) among firefighters contributes to their job-related stress. However, the relationship between burnout and PTSD in firefighters has rarely been studied. This study therefore explored the association between burnout and its related factors, such as trauma and violence, and PTSD symptoms among firefighters in Korea. Methods: A total of 535 firefighters participated in the Firefighter Research on Enhancement of Safety & Health study at 3 university hospitals from 2016 to 2017. The 535 participants received a baseline health examination, including questionnaires assessing their mental health. A Web-based survey was also conducted to collect data on job-related stress, history of exposure to violence, burnout, and trauma experience. The associations among burnout, its related factors, and PTSD symptoms were investigated using structural equation modeling. Results: Job demands (${\beta}=0.411$, p<0.001) and effort-reward balance (${\beta}=-0.290$, p<0.001) were significantly related to burnout. Burnout (${\beta}=0.237$, p<0.001) and violence (${\beta}=0.123$, p=0.014) were significantly related to PTSD risk. Trauma (${\beta}=0.131$, p=0.001) was significantly related to burnout; however, trauma was not directly associated with PTSD scores (${\beta}=0.085$, p=0.081). Conclusions: Our results show that burnout and psychological, sexual, and physical violence at the hands of clients directly affected participants' PTSD symptoms. Burnout mediated the relationship between trauma experience and PTSD.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.42
• /
• pp.10.1-10.9
• /
• 2020

Background: The aim of this study was to evaluate the long-term clinical stability of implants with acid-etched surfaces sandblasted with alumina using retrospective analyses of the survival rate, success rate, primary and secondary stability, complications, and marginal bone loss of the implants. Methods: Patients who had implants placed (TS III SA, SS II SA, SS III SA, and U III SA) with SA surfaces from Osstem (Osstem Implant Co., Busan, Korea) at the Seoul National University Bundang Hospital, from January 2008 to December 2010 were selected for the study. Patients' medical records and radiographs (panorama, periapical view) were retrospectively analyzed to investigate sex, age, location of implantation, diameter, and length of the implants, initial and secondary stability, presence of bone grafting, types of bone grafting and membranes, early and delayed complications, marginal bone loss, and implant survival rate. Results: Ninety-six implants were placed in 45 patients. Five implants were removed during the follow-up period for a total survival rate of 94.8%. There were 14 cases of complications, including 6 cases of early complications and 8 cases of delayed complications. All five implants that failed to survive were included in the early complications. The survival of implants was significantly associated with the occurrence of complications and the absorption of bone greater than 1 mm within 1 year after prosthetic completion. In addition, the absorption of bone greater than 1 mm within 1 year after prosthetic completion was significantly associated with the occurrence of complications, primary stability, and implant placement method. Five cases that failed to survive were all included in the early complications criteria such as infection, failure of initial osseointegration, and early exposure of the fixture. Conclusions: Of the 96 cases, 5 implants failed resulting in a 94.8% survival rate. The failed implants were all cases of early complications such as infection, failure of initial osseointegration, and early exposure of the fixtures. Periimplantitis was mostly addressed through conservative and/or surgical treatment and resulted in very low prosthetic complications. Therefore, if preventive measures are taken to minimize initial complications, the results can be very stable.

• The Journal of Korea Assosiation for Disability and Oral Health
• /
• v.15 no.1
• /
• pp.84-88
• /
• 2019

Malocclusion occurs more frequently in Special Health Care Needed (SHCN) patients than those in general. As caregiver's needs for orthodontic treatment tend to increase, the dentist should know how to decide the extent of treatment. This case report is about orthodontic treatment for two SHCN patients; one patient with cerebral palsy, and another patient with autism. A 10-year-old patient with cerebral palsy showed protrusion and rotation of maxillary anterior teeth. To resolve his chief complaints and make better oral hygiene, he underwent orthodontic treatment using micro tube appliances for 6 months. Another 11-year-old patient with autism had anterior crossbite and showed space deficiency of #13 and chronic gingivitis because of poor oral hygiene. She underwent orthodontic treatment with maxillary skeletal expander, facemask and AP expansion appliance. After 18 months we found positive overjet and ended the treatment. When giving SHCNs orthodontic treatment, the extent of treatment can be chosen according to the patient's cooperative ability and the traits of disabilities. Before initiating orthodontic treatment, the caregivers should be aware of their limitations of the treatment. Since oral hygiene is crucial factor in every dental treatment, education of oral hygiene process for the caregivers and SHCN patient must be done before the orthodontic treatment.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.35 no.3
• /
• pp.153-159
• /
• 2019

Purpose: Aims to analyze the occlusal wear patterns in maxillary posterior teeth with palatal side abfractions and study the association between occlusal force and abfractions. Materials and Methods: This study was conducted in a total of 308 teeth from 148 patients with palatal side abfractions in maxillary posterior teeth. The occlusal wears in maxillary premolars and molars with palatal side abfractions were classified and recorded. The classification was done by type of teeth, age, and gender, and in order to evaluate the statistical significance between groups, chi-square test was conducted (${\alpha}=0.05$). Results: Palatal side abfractions in maxillary posterior teeth were observed at the highest frequency in the 1st molars, and in all teeth with palatal side abfractions, more than one occlusal wear was observed. In classification by type of teeth, by age, and by gender, the occlusal wears in teeth with palatal side abfractions were observed at high frequency in cuspal inclined plane, central fossa, and marginal ridge, and there was a statistical significance (P < 0.05). Conclusion: Palatal side abfractions were observed at the highest frequency in maxillary 1st molars, and in all maxillary posterior teeth where palatal side abfractions were found, the occlusal wears were observed. And the occlusal wears were observed at high frequency in cuspal inclined plane, central fossa and marginal ridge. Such results show that abfraction is associated with occlusal force.

• The Journal of Korea Assosiation for Disability and Oral Health
• /
• v.14 no.2
• /
• pp.97-101
• /
• 2018

Lesch-Nyhan syndrome is a rare X-linked recessive genetic disorder. During purine metabolism, the hypoxanthine guanine phosphribosyl transferase (HGPRT) enzyme is deficient causing phosphoribosyl transferase to accumulate and resulting in excessive uric acid. Clinical symptoms include hypercalcemia, choreoathetosis, spasticity, mental retardation, and self-injury to lips, tongue or fingers. This results not only in pain caused by the self-injury but also secondary infection of the wound site and the esthetic damage of the soft tissue defect. Dental treatments include conservative methods using intraoral appliances such as soft mouthguards, fixed lip bumpers, and occlusal guards, and invasive methods such as extraction of all teeth or forming an artificial anterior open bite. We report two cases of Lesch-Nyhan syndrome patients with self-mutilation behavior; one was treated with a preservative method using a soft mouthguard, and the other was treated with extraction of all teeth.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.32 no.5
• /
• pp.191-198
• /
• 2022

Zirconia and titanium alloys, which are mainly used for dental implant materials, have poor osseointegration and osteogenesis abilities due to their bioinertness with low bioactivity on surface. In order to improve their surface bioinertness, surface modification with a bioactive material is an easy and simple method. In this study, akermanite (Ca₂MgSi₂O₇), a silicate-based bioceramic material with excellent bone bonding ability, was synthesized by a solid-state reaction and investigated its bioactivity from the analysis of surface dissolution and precipitation of hydroxyapatite particles in SBF solution. Calcium carbonate (CaCO₃), magnesium carbonate (MgCO₃), and silicon dioxide (SiO₂) were used as starting materials. After homogeneous mixing of starting materials by ball milling and the drying of at oven, uniaxial pressing was performed to form a compacted disk, and then heat-treated at high temperature to induce the solid-state reaction to akermanite. Bioactivity of synthesized akermanite disk was evaluated with the reaction temperature from the immersion test in SBF solution. The higher the reaction temperature, the more pronounced the akermanite phase and the less the surface dissolution at particle surface. It resulted that synthesized akermanite particles had high bioactivity on particle surface, but it depended on reacted temperature and phase composition. Moderate dissolution occurred at particle surfaces and observed the new precipitated hydroxyapatite particles in synthetic akermanite with solid-state reaction at 1100℃.

• Journal of Family Resource Management and Policy Review
• /
• v.26 no.3
• /
• pp.49-64
• /
• 2022

This study aims to investigate unmet healthcare needs due to economic or non-economic difficulties among the elderly aged 65 or older. Using Korea Health Panel Survey (KHPS) data from 2018, the elderly are classified into one of four groups (health insurance subscribers, non-take-up, lower income relief, and medical aid recipients) based on their level of medical vulnerability. For hospital or dental care, the prevalence rates of unmet healthcare needs due to economic and non-economic difficulties are 12.6% and 10.6%, respectively. The prevalence rate of unmet healthcare needs due to economic difficulty in the medically vulnerable group was much higher than that of the non-vulnerable group-that is, health insurance subscribers. After controlling for other influential factors, medical vulnerability has a great impact on the prevalence rates of unmet healthcare needs due to economic difficulties. Compared to health insurance subscribers, the non-take-up, the lower relief, and the medical aid recipients are 1.4 times, 3.3 times, and 2.4 times more likely to experience unmet healthcare needs due to economic difficulty, respectively. The results of this study can provide important policy implications for securing essential healthcare resources for the elderly.