OBJECTIVES: Classification of the degree of postoperative nerve damage according to contact with the mandibular canal and buccal cortical bone has been studied, but there is a lack of research on the difference in postoperative courses according to contact with buccal cortical bone. In this study, we divided patients into groups according to contact between the mandibular canal and the buccal cortical bone, and we compared the position of the mandibular canal in the second and first molar areas. MATERIALS AND METHODS: Class III patients who visited the Dankook University Dental Hospital were included in this study. The following measurements were made at the second and first molar positions: (1) length between the outer margin of the mandibular canal and the buccal cortical margin (a); (2) mandibular thickness at the same level (b); (3) Buccolingual ratio=(a)/(b)×100; and (4) length between the inferior margin of the mandibular canal and the inferior cortical margin. RESULTS: The distances from the canal to the buccal bone and from the canal to the inferior bone and mandibular thickness were significantly larger in Group II than in Group I. The buccolingual ratio of the canal was larger in Group II in the second molar region. CONCLUSION: If mandibular canal is in contact with the buccal cortical bone, the canal will run closer to the buccal bone and the inferior border of the mandible in the second and first molar regions.
Classification ; Cone-Beam Computed Tomography ; Humans ; Mandible ; Mandibular Nerve ; Molar ; Osteotomy*

OBJECTIVES: This study explored socioeconomic disparities in Korea using health insurance type as a proxy during the ongoing coronavirus disease 2019 (COVID-19) pandemic. METHODS: We conducted a retrospective cohort study using Korea’s nationwide healthcare database, which contained all individuals who received a diagnostic test for COVID-19 (n=232,390) as of May 15, 2020. We classified our cohort by health insurance type into beneficiaries of the National Health Insurance (NHI) or Medicaid programs. Our study outcomes were infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and COVID-19-related outcomes, a composite of all-cause death, intensive care unit admission, and mechanical ventilation use. We estimated age-, sex-, and Charlson comorbidity index score–adjusted odds ratios (aORs) with 95% confidence intervals (CIs) using a multivariable logistic regression analysis. RESULTS: Of the 218,070 NHI and 14,320 Medicaid beneficiaries who received COVID-19 tests, 7,777 and 738 tested positive, respectively. The Medicaid beneficiaries were older (mean age, 57.5 vs. 47.8 years), more likely to be males (47.2 vs. 40.2%), and had a higher comorbidity burden (mean CCI, 2.0 vs. 1.7) than NHI beneficiaries. Compared to NHI beneficiaries, Medicaid beneficiaries had a 22% increased risk of SARS-CoV-2 infection (aOR, 1.22; 95% CI, 1.09 to 1.38), but had no significantly elevated risk of COVID-19-related outcomes (aOR 1.10, 95% CI 0.77 to 1.57); the individual events of the composite outcome yielded similar findings. CONCLUSIONS As socioeconomic factors, with health insurance as a proxy, could serve as determinants during the current pandemic, pre-emptive support is needed for high-risk groups to slow its spread.

OBJECTIVES: This study explored socioeconomic disparities in Korea using health insurance type as a proxy during the ongoing coronavirus disease 2019 (COVID-19) pandemic. METHODS: We conducted a retrospective cohort study using Korea’s nationwide healthcare database, which contained all individuals who received a diagnostic test for COVID-19 (n=232,390) as of May 15, 2020. We classified our cohort by health insurance type into beneficiaries of the National Health Insurance (NHI) or Medicaid programs. Our study outcomes were infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and COVID-19-related outcomes, a composite of all-cause death, intensive care unit admission, and mechanical ventilation use. We estimated age-, sex-, and Charlson comorbidity index score–adjusted odds ratios (aORs) with 95% confidence intervals (CIs) using a multivariable logistic regression analysis. RESULTS: Of the 218,070 NHI and 14,320 Medicaid beneficiaries who received COVID-19 tests, 7,777 and 738 tested positive, respectively. The Medicaid beneficiaries were older (mean age, 57.5 vs. 47.8 years), more likely to be males (47.2 vs. 40.2%), and had a higher comorbidity burden (mean CCI, 2.0 vs. 1.7) than NHI beneficiaries. Compared to NHI beneficiaries, Medicaid beneficiaries had a 22% increased risk of SARS-CoV-2 infection (aOR, 1.22; 95% CI, 1.09 to 1.38), but had no significantly elevated risk of COVID-19-related outcomes (aOR 1.10, 95% CI 0.77 to 1.57); the individual events of the composite outcome yielded similar findings. CONCLUSIONS As socioeconomic factors, with health insurance as a proxy, could serve as determinants during the current pandemic, pre-emptive support is needed for high-risk groups to slow its spread.

BACKGROUND AND OBJECTIVES: With the currently available diagnostic procedure, hearing impaired children are diagnosed at an early age and hearing aids are fitted soon thereafter. Thus, appropriateness of using available correction methods for adult ears and ear models for determining and predicting hearing aid characteristics for these children need to be examined. The objectives of this study are to create a database of resonance frequency and length of external auditory canal (EAC) in all age groups and to adjust the peak frequency response of hearing aid system to take account of the changing resonance peak frequency as child gets older. MATERIALS AND METHOD: We studied 437 ears with no age limitation. We measured rear ear unaided response (REUR) with Rastronics frequency response analyzer and external ear canal length using silastic tube under microscopic or otoscopic finding. Statistical analyses were performed to determine age differences. RESULTS: Ear canal length increased with age, and an adult value was achieved by the age of 14 years. Resonance frequency decreased with age, and reached to an adult value by the age of 9 years. There was significant relationship between ear canal length and resonance frequency. CONCLUSION: Alteration in resonance frequency with age may have practical implications by affecting the insertion gain of hearing aid system in children. The data may be used as useful adjustment factors to correct the current hearing aid system in children.
Adult ; Child ; Ear ; Ear Canal* ; Hearing ; Hearing Aids ; Humans

BACKGROUND AND OBJECTIVES: Although it is widely accepted that nasal obstruction leads to snoring and sleep apnea, the relationship between these variable factors is not clear. Moreover, while nasal blockage in human is known to produce sleep- disordered breathing, it is controversial whether nasal obstruction itself produces obstructive apnea and whether it causes changes in the sleep stages. The purpose of this study is to measure changes in sleep physiology by nasal blockage alone and to evaluate whether the nasal blockage itself ca>i produce the sleep apnea syndrorm or not. MATERIAL AND METHOD: Normal thirty subjects, 15 males and 15 females, who had sleep apnea episodes <2 by polysomnography during sleep, were evaluated using Alice III polysomnography after both nostrils opened, unilateral nostril blockage, and bilateral nostril blockage. The parameters of measurement were hypopnea and apnea episodes and apnea type, apnea index (AI), respiratory disturbance index (RDI), SO and sleep stages. A statistical analysis was performed using a wicoxon signed rank test. RESULTS: Bilateral nasal blockage induces significantly increased apnea and hypopnea episodes, AI, and RDI but induces significantly decreased mean and lowest O. saturation. Also, bilateral nasal blockage significantly prolonged S,-NREM sleep and decreased REM sleep (p(0.05). However, these changes did not correspond with the criteria of the sleep apnea syndrome. CONCLUSION: Unilateral nasal obstruction does not cause any significant changes in the measured parameters compared to the normal nose of unblocked state. Bilateral nasal obstruction does not induce the obstructive sleep apnea syndrome by itself. However, it causes changes in the sleep stages and increases sleep apnea episodes significantly.
Apnea ; Female ; Humans ; Male ; Nasal Obstruction* ; Nose ; Physiology ; Polysomnography ; Respiration ; Sleep Apnea Syndromes* ; Sleep Apnea, Obstructive ; Sleep Stages ; Sleep, REM ; Snoring

Purpose: To investigate the effect of regular monitoring of pulmonary function and ventilatory status on the initiation of non-invasive ventilation (NIV) between patients who were routinely monitored before receiving NIV and those who were not. Materials and Methods: This retrospective cohort study included subjects with Duchenne muscular dystrophy (DMD) who first received NIV between 2010 and 2019. The subjects were assigned to either the regular-follow-up (REG) group or the non-REG group, according to their follow-up status, before initiating NIV. We compared the number of emergent cases, the results of nocturnal ventilatory monitoring, and the pulmonary function of each group at initial ventilatory support. Results: In total, 73 subjects were enrolled in the REG group and 47 subjects in the non-REG group. There were significantly more emergency cases due to respiratory insufficiency in the non-REG group (12/47, 25.5%) than in the REG group (3/73, 4.1%). At the time of initial ventilatory support, hypoventilatory symptoms were more common and relatively severe in the non-REG group (37/47, 78.7%) than in the REG group (18/73, 24.7%). The average age at initial ventilatory support of the non-REG group was 2.15 years older than that of the subjects in the REG group. Moreover, subjects who were not regularly monitored exhibited greater deterioration in pulmonary function compared to those who were regularly followed up. Conclusion Regular evaluation of pulmonary function and ventilatory status before the onset of ventilatory insufficiency is crucial to reduce the risk of patients with DMD requiring emergency care due to ventilatory insufficiency.

Objectives: This research delves into the application of texture analysis in spine computed tomography (CT) scans and its correlation with bone mineral density (BMD), as determined by dual-energy X-ray absorptiometry (DXA).It specifically addresses the discordance between the 2 measurements, suggesting that certain spinal-specific factors may contribute to this discrepancy. Methods: The study involved 405 cases from a single institution collected between May 6, 2012 and June 30, 2021. Each case underwent a spinal CT scan and a DXA scan. BMD values at the lumbar region (T12 to S1) and total hip were recorded. Texture features from axial cuts of T12 to S1 vertebrae were extracted using gray-level co-occurrence matrices, and a regression model was constructed to predict the BMD values. Results: The correlation between CT texture analysis results and BMD from DXA was moderate, with a correlation coefficient ranging between 0.4 and 0.5. This discordance was examined in light of factors unique to the spine region, such as abdominal obesity, aortic calcification, and lumbar degenerative changes, which could poten tially affect BMD measurements. Conclusions Emerging from this study is a novel insight into the discordance between spinal CT texture analysis and DXA-derived BMD measurements, highlighting the unique influence of spinal attributes. This revelation calls into question the exclusive reliance on DXA scans for BMD assessment, particularly in scenarios where DXA scanning may not be feasible or accurate.

OBJECTIVE: To evaluate pulmonary functions of patients with amyotrophic lateral sclerosis (ALS), Duchenne muscular dystrophy (DMD), and myotonic muscular dystrophy (MMD) at the onset of ventilatory insufficiency. METHODS: This retrospective study included ALS, DMD, and MMD patients with regular outpatient clinic follow-up in the Department of Rehabilitation Medicine at Gangnam Severance Hospital before the application of non-invasive positive pressure ventilation (NIPPV). The patients were enrolled from August 2001 to March 2014. If patients experienced ventilatory insufficiency, they were treated with NIPPV, and their pulmonary functions were subsequently measured. RESULTS: Ninety-four DMD patients, 41 ALS patients, and 21 MMD patients were included in the study. The mean SpO2 was lower in the MMD group than in the other two groups. The mean forced vital capacity (FVC) in the supine position was approximately low to mid 20% on average in DMD and ALS patients, whereas it was 10% higher in MMD patients. ALS patients showed a significantly lower FVC in the supine position than in the sitting position. Maximal insufflation capacity, unassisted peak cough flow, maximum inspiratory pressure (MIP), and maximum expiratory pressure (MEP) were significantly higher in MMD group than in the other groups. MEP was significantly the lowest in DMD patients, followed by in ALS, and MMD patients, in order. CONCLUSION: Disease-specific values of pulmonary function, including FVC, MEP, and MIP, can be accurately used to assess the onset of ventilatory insufficiency in patients with ALS, DMD, and MMD.
Ambulatory Care Facilities ; Amyotrophic Lateral Sclerosis* ; Cough ; Follow-Up Studies ; Humans ; Insufflation ; Muscular Dystrophies* ; Muscular Dystrophy, Duchenne* ; Myotonic Dystrophy ; Neuromuscular Diseases ; Positive-Pressure Respiration ; Rehabilitation ; Respiratory Insufficiency ; Retrospective Studies ; Supine Position ; Vital Capacity

BACKGROUND AND OBJECTIVES: Some patients who have undergone tonsillectomy complain of voice change, but few studies for the mechanism of voice change were found. To solve this problem, study of voice change after tonsillectomy and adenotonsillectomy was done. MATERIALS AND METHODS: We analyzed voice change of 22 patients who underwent tonsillectomy and 15 patients who underwent adenotonsillectomy at CSL (computerized speech laboratory), St. Benedict Hospital. With the measured cross sectional area of vocal tract and its length from the glottis on MR images, we presented the change of cross sectional area schematically after tonsillectomy. RESULTS: Acoustically, the frequencies of the second formant of /e/ and /i/ increased and that of the first formant of /u/ decreased significantly after tonsillectomy and the frequency of the second formant of /o/ and those of the second and third formants of /i/ and /u/ increased significantly after adenotonsillectomy. It was also showed acoustically that the formant bandwidths of /a/ and /hana/ after tonsillectomy and those of /e/ and /hana/ after adenotonsillectomy increased due to nasalization. Anatomically, it was showed that the cross sectional area of oropharyngeal cavity increased and coupling effect of vocal tract happened after tonsillectomy. CONCLUSION: This study showed that acoustic characteristics and vocal tract shapes of the patients did change following tonsillectomy and adenotonsillectomy. It is imperative that we explain to patients about the postoperative voice change. Research should also be done to find ways to induce better voice changes following the operations.
Acoustics* ; Glottis ; Humans ; Magnetic Resonance Imaging ; Tonsillectomy* ; Voice*

Since 2001, financial support has been provided for all patients with neuromuscular disease (NMD) who require ventilatory support due to the paralysis of respiratory muscles in Korea. The purpose of this study was to identify ventilator usage status and appropriateness in these patients. We included 992 subjects with rare and incurable NMD registered for ventilator rental fee support. From 21 February 2011 to 17 January 2013, ventilator usage information, regular follow-up observation, and symptoms of chronic hypoventilation were surveyed by phone. Home visits were conducted for patients judged by an expert medical team to require medical examination. Abnormal ventilatory status was assessed by respiratory evaluation. Chronic respiratory insufficiency symptoms were reported by 169 of 992 subjects (17%), while 565 subjects (57%) did not receive regular respiratory evaluation. Ventilatory status was abnormal in 102 of 343 home-visit subjects (29.7%). Although 556 subjects (56%) reported 24-hour ventilator use, only 458 (46%) had an oxygen saturation monitoring device, and 305 (31%) performed an airstacking exercise. A management system that integrates ventilator usage monitoring, counselling and advice, and home visits for patients who receive ventilator support could improve the efficiency of the ventilator support project.
Adult ; Aged ; Disease Management ; Female ; Home Care Services ; Humans ; Interviews as Topic ; Male ; Middle Aged ; Neuromuscular Diseases/complications/economics/*psychology ; Republic of Korea ; Respiratory Insufficiency/complications/*prevention & control ; Surveys and Questionnaires ; Ventilators, Mechanical