Narcissistic personality is an ego centric personality characterized by obsession with oneself, disregard for others, and lack of empathy. It forms a spectrum from normal to pathological levels. A narcissistic person unconsciously fears death because he/she pursues immortality and omnipotence. A narcissistic person does not consider others important. Thus, he/she does not mourn separation or loss. It might be a characteristic defense of narcissistic personality. The authors selected by Japanese author Yoko Sano as a text. Many people loved the cat and cried and mourned when the cat died. However, he was reborn immediately a million times. The cat loved only itself. The cat then met a white cat and fell in love for the first time. They lived to-gether. As time passed, the white cat died. For the first time, the cat cried out loud in sadness. After crying and crying, he stoppedmoving and dying. He was not reborn again. The authors viewed the cat as a narcissistic personality and interpreted its active avoidance and denial of separation, death, and mourning as a narcissistic defense. Repeating this only strengthened his narcissistic traits.However, the momentum of change was falling in love. Losing a loved one and going through the process of mourning the eternalseparation of death for the first time became the trigger for the change in narcissistic personality.

Background and Objectives: Obstructive sleep apnea (OSA) is an obstructive airflow disorder that occurs in the upper respiratory tract during sleep and is therefore associated with the occurrence of cardiovascular diseases. By examining the Lund-Mackay (L-M) scores and maxillary sinus mucosal conditions according to the severity of sleep breathing disorder (SBD), we tried to find out the association between SBD and sinus mucosal change.Subjects and Method Of the 189 patients who underwent sinus CT with a polysomnography test, 175 patients were enrolled in our study. We investigated the average L-M score and L-M score of five or higher, and the ratio of maxillary sinus mucosal thickness (MSMT) of 2 mm or higher. Results: The average L-M score of study population was 0.98 points and the L-M score of five or more was found in 14 patients (8%). The MSMT of 2 mm or more was found in 25.5% of the study group. The average L-M scores for the different groups, namely, the simple snoring group, the mild OSA, the moderate OSA, and the severe OSA were 1.31 points, 0.77 points, 0.91 points, and 1.08 points, respectively. There was no significant difference (p=0.736) among them, and there was no correlation between the apnea-hypopnea index score and the L-M score (r=-0.052, p=0.499). There was no significant difference between OSA severity and MSMT (p=0.490). Conclusion There was no significant difference between the L-M score and MSMT depending on the severity of SBD. Therefore, it is believed that SBD will have little effect on the sinus mucosa.

Background and Objectives: It is important to identify variations of paranasal sinuses during sinus surgery. The Onodi cell (OC), a variant of the paranasal sinuses, is the most posterior ethmoid cell with a close relationship with the optic nerve (ON). The purpose of this study is to evaluate the prevalence of OCs and analyze the relationship of OCs with ON in Koreans.Subjects and Method This retrospective study utilized CT images of 526 slides from 263 Korean adults. The prevalence of the OCs and the degree of indentation of the ON within the OC was determined using binary logistic regression analysis. Results: The OCs were observed in 37.3% of 263 subjects and in 27.6% of 526 slides. The OCs are found more frequently in males than in females (p=0.01), and also more frequently in the right side than in the left side (p=0.001). Binary logistic regression analysis revealed that the ON protrusion in female was 0.339 times lower than in male and 1.052 times higher with the increased age. The ON protrusion within the OC in the postsellar type was 10.214 times higher than that in the presellar. Conclusion The OCs were observed in 37.3% of the Koreans. The protrusion of the ON within the OCs increased in male and in the postsellar type of the sphenoid sinus.

Background and Objectives: It is necessary to understand the variations of the paranasal sinuses (PNS) and other anatomical structures during an endoscopic sinus surgery (ESS). The purpose of this study was to investigate any association between the degree of frontal sinus (FS) pneumatization and the development of the PNS structures. Subjects and Method We analyzed 311 PNS computed tomography (CT) scans (622 sinuses, including the left and right sides). We classified FS into type I (aplasia), type II (hypoplasia), and type III (control). We assessed and compared the middle turbinate pneumatization (MTP), superior turbinate pneumatization (STP), agger nasi cell (ANC), infraorbital cell (IOC), optic nerve (ON) type, and vidian nerve (VN) type with the pneumatization of the FS. We further studied for any association between the degree of pneumatization of the FS, maxillary sinus (MS), and sphenoid sinus (SS) and the lateral lamella length (LLL). Results: MTP, ANC, and IOC rates according to the FS types were not significant (p>0.05). Both type II and III showed more frequent occurrences of STP than type I (p=0.005). The ON type III and IV were significantly frequent in the FS type III (p<0.001). The occurrence of VN type III in the FS type I was significant (p<0.001). When comparing the pneumatizations of FS with MS or SS, there were no significant correlations between them (p>0.05). In the FS type II and III, the LLL was significantly greater than in type I (p<0.001). Conclusion Increased FS pneumatization shows greater indentation of ON and VN into the SS, as well as increased LLL. During ESS, it is important to recognize the possibility of structural damage of ON, VN, and LLL according to FS pneumatization.

Background and Objectives: The olfactory fossa is an important anatomical structure to prevent surgical complications such as skull base injury and meningitis. The purpose of this study is to determine if there is a difference in lateral lamella length (LLL) between the left and right sides, a topic that has been studied rarely in Korea. Subjects and Method: We analyzed 592 left and right sides of 296 PNS CTs. We measured LLL as the distance between the fovea ethmoidalis and the horizontal cribriform plate in the olfactory fossa of the coronal surface where the crista galli was observed. Results: The average LLL on the left side was significantly longer than that on the right. Age and LLL showed a negative correlation. Multiple regression analysis revealed younger age and left side as independent variables for predicting increasing LLL. Conclusion There was a significant difference between the two sides of LLL on sinus CT in Koreans. Before sinus surgery, the asymmetry of the ethmoid roof must be assessed, even by skilled doctors. If the height of the ethmoid roof is asymmetric, extra care is required during sinus surgery.

Acute otitis media (AOM) is diagnosed in patients with acute onset of signs and symptoms of inflammation in the middle ear, accompanied by middle ear effusion. AOM is a common infectious disease in children, and its diagnosis and treatment can have significant impacts on the health of children.Current Concepts: The evidence-based clinical practice guidelines in Korea and other countries provide recommendations to primary care clinicians regarding the management of children with AOM. The treatment strategy for AOM depends on the patient’s age, severity of symptoms, the presence of otorrhea, and the laterality.Discussion and Conclusion: For children aged from 6-months to 2-years with unilateral non-severe AOM and children aged 2 years or older with unilateral or bilateral non-severe AOM, the published guidelines provide the option of observation rather than immediate treatment with antibiotics. High-dose amoxicillin (80 to 90 mg a day) is the firstline antibiotic for treating AOM in patients without penicillin allergies. Children in whom symptoms persist after 48 to 72 hours of antibiotic treatment should be re-examined and amoxicillin/clavulanate should be used as second-line antibiotics. Careful follow-up is required to identify the complications and sequelae of AOM, and to determine the optimum treatment.

Background and Objectives: The olfactory fossa is an important anatomical structure to prevent surgical complications such as skull base injury and meningitis. The purpose of this study is to determine if there is a difference in lateral lamella length (LLL) between the left and right sides, a topic that has been studied rarely in Korea. Subjects and Method: We analyzed 592 left and right sides of 296 PNS CTs. We measured LLL as the distance between the fovea ethmoidalis and the horizontal cribriform plate in the olfactory fossa of the coronal surface where the crista galli was observed. Results: The average LLL on the left side was significantly longer than that on the right. Age and LLL showed a negative correlation. Multiple regression analysis revealed younger age and left side as independent variables for predicting increasing LLL. Conclusion There was a significant difference between the two sides of LLL on sinus CT in Koreans. Before sinus surgery, the asymmetry of the ethmoid roof must be assessed, even by skilled doctors. If the height of the ethmoid roof is asymmetric, extra care is required during sinus surgery.

Acute otitis media (AOM) is diagnosed in patients with acute onset of signs and symptoms of inflammation in the middle ear, accompanied by middle ear effusion. AOM is a common infectious disease in children, and its diagnosis and treatment can have significant impacts on the health of children.Current Concepts: The evidence-based clinical practice guidelines in Korea and other countries provide recommendations to primary care clinicians regarding the management of children with AOM. The treatment strategy for AOM depends on the patient’s age, severity of symptoms, the presence of otorrhea, and the laterality.Discussion and Conclusion: For children aged from 6-months to 2-years with unilateral non-severe AOM and children aged 2 years or older with unilateral or bilateral non-severe AOM, the published guidelines provide the option of observation rather than immediate treatment with antibiotics. High-dose amoxicillin (80 to 90 mg a day) is the firstline antibiotic for treating AOM in patients without penicillin allergies. Children in whom symptoms persist after 48 to 72 hours of antibiotic treatment should be re-examined and amoxicillin/clavulanate should be used as second-line antibiotics. Careful follow-up is required to identify the complications and sequelae of AOM, and to determine the optimum treatment.

OBJECTIVES: We investigated the characteristics of Streptococcus mutans in the national culture collection from Korea. Twenty-nine (dental plaque, n=27; endodontic infections, n=1; blood, n=1) isolates were included in this study. METHODS: Antimicrobial susceptibilities were tested using the disk diffusion test. Multilocus sequence typing (MLST), serotyping, and collagen-binding genes were used for polymerase chain reaction (PCR) and direct sequencing. A collagen-binding (to assess the adhesion properties) assay was performed. S. mutans demonstrated high susceptibility to antimicrobial agents. Differences in collagen-binding abilities of the cnm-positive and -negative groups were compared using the Mann-Whitney U test (P<0.05). RESULTS: MLST analyses revealed 25 sequence types (STs), 17 of which (ST213-ST229) contained new alleles. The strains were classified into four serotypes with the c type encompassing 79.3% of all strains, while the e, f, and k types representing 6.9% each. Analysis of the cnm and cbm genes, which encode the two surface adhesin components of S. mutans, revealed three cnm-positive strains, each displaying greater adhesion ability than those of the cnm-negative strains. CONCLUSIONS This study highlights the presence of a wide variety of S. mutans genotypes in Korea. These findings may provide useful information regarding the pathogenesis of infectious diseases, such as dental caries.

OBJECTIVES: The purpose of this study was to identify and compare the difference and related factors with general characteristic and health behaviors, a experience of diagnosis and treatment of chronic diseases between rural and urban among elderly in Korea. METHODS: We used the data of Community Health Survey 2017 which were collected by the Korean Center for Disease Control and Prevention. The study population comprised 67,835 elderly peopled aged 65 years or older who participated in the survey. The chi-square test, univariate and multivariate logistic regression analysis were used to analyze data. RESULTS: We identified many significant difference of health behaviors, an experience of diagnosis and treatment with chronic diseases between rural and urban. Compared to urban elderly, the odds ratios (ORs) (95% confidence interval) of rural elderly were 1.136 (1.092–1.183) for diagnosis of diabetes, 1.278 (1.278–1.386) for diagnosis of dyslipidemia, 0.940 (0.904–0.977) for diagnosis of arthritis, 0.785(0.736–0.837) for treatment of arthritis, 1.159 (1.116–1.203) for diagnosis of cataracts, and 1.285(1.200–1.375) for treatment of cataracts. In the experience of diagnosis and treatment of chronic diseases, various variables were derived as contributing factors for each disease. Especially, there were statistically significant difference in the experience of diabetes diagnosis, arthritis diagnosis, cataract diagnosis and dyslipidemia except for hypertension diagnosis (p<0.01) between urban and rural elderly. There were statistically significant differences in the experience of treatment for arthritis and cataract (p<0.01), but there was no significant difference in the experience of treatment for hypertension, diabetes, dyslipidemia between urban and rural elderly. CONCLUSION Therefore, it would be necessary to implement a strategic health management project for diseases that showed significant experience of chronic diseases with diagnosis and treatment, reflecting the related factors of the elderly chronic diseases among the urban and rural areas.