Extremely Electron-Withdrawing Lewis-Paired CN Groups for Organic p-Dopants.

P-type chemical doping (p-doping) is a key technique to modulate the optical, electrical, and electronic properties of organic semiconductors. However, typical functional groups in organic p-dopants have insufficient electron-withdrawing strength, and the inevitable diffusion of dopants in host matrices degrades doping stabilities. Herein, we utilize extremely electron-withdrawing Lewis-paired CN groups as a new class of building blocks for designing unprecedentedly strong organic p-dopants with excellent doping stability. Various Lewis acids are paired with CN-functionalized conjugated molecules in the solution state, which strengthens the electron-withdrawing properties of CN groups almost twofold. The large dopants afford outstanding doping stability against continuous heating and long-term atmospheric exposure, which is promising for practical applications in devices. Given the broad applicability of this simple combinatorial approach, it may impact many fields of (opto)electronics.

Evaluation of the condylar position in younger and older adults with or without temporomandibular symptoms by using cone beam computed tomography.

STATEMENT OF PROBLEM: Recent studies in young adults have questioned the influence of discrepancies between central and maximal intercuspal positions in temporomandibular disorders (TMDs). However, whether this finding was because this type of etiologic agent requires time for the development of changes in the condylar position is unclear. PURPOSE: The purpose of this clinical study was to use cone beam computed tomography (CBCT) to evaluate the presence or absence of discrepancies between the centric relation (CR) and maximum intercuspation (MI) in younger and older adults in populations with or without TMDs. MATERIAL AND METHODS: The sample was composed of 80 volunteers, 40 younger individuals aged 18 to 25 years (27 women and 13 men), half with and half without TMD symptoms, and 40 older participants aged 35 to 50 years (30 women and 10 men), half with and half without TMD symptoms. The TMD symptoms were diagnosed by using the diagnostic (standard) criteria for TMD research (RDC/TMD). Two CBCT scans were performed on each participant, one in MI and another in CR. Measurements of the joint space were performed in coronal and sagittal cuts of the temporomandibular joints, and the collected data were statistically analyzed by using the Mann-Whitney U test (α=.05). RESULTS: No significant differences were found when the CR and MI positions and the presence or absence of TMD symptoms were compared in the younger and older groups. However, when the younger and older groups were compared, significant differences were found in all measures used in this study. CONCLUSIONS: The condyle and mandibular fossa do not seem to be influenced by the CR or MI positions or by the presence or absence of TMD symptoms, but age seems to lead to a quantitative increase in the relationship between these structures.

Prenylated Coumaric Acids from Artemisia scoparia Beneficially Modulate Adipogenesis.

Two new diprenylated coumaric acid isomers (1a and 1b) and two known congeners, capillartemisin A (2) and B (3), were isolated from Artemisia scoparia as bioactive markers using bioactivity-guided HPLC fractionation. Their structures were determined by spectroscopic means, including 1D and 2D NMR methods and LC-MS, with their purity assessed by 1D 1H pure shift qNMR spectroscopic analysis. The bioactivity of compounds was evaluated by enhanced accumulation of lipids, as measured using Oil Red O staining, and by increased expression of several adipocyte marker genes, including adiponectin in 3T3-L1 adipocytes relative to untreated negative controls. Compared to the plant's 80% EtOH extract, these purified compounds showed significant but still weaker inhibition of TNFα-induced lipolysis in 3T3-L1 adipocytes. This suggests that additional bioactive substances are responsible for the multiple metabolically favorable effects on adipocytes observed with Artemisia scoparia extract.

Optimization of extraction conditions for osthol, a melanogenesis inhibitor from Cnidium monnieri fruits.

CONTEXT: Coumarin derivatives have been reported to inhibit melanin biosynthesis. OBJECTIVE: The melanogenesis inhibitory activity of osthol, a major coumarin of the fruits of Cnidium monnieri Cusson (Umbelliferae), and optimized extraction conditions for the maximum yield from the isolation of osthol from C. monnieri fruits were investigated. MATERIALS AND METHODS: B16F10 melanomas were treated with osthol at concentration of 1, 3, and 10 µM for 72 h. The expression of melanogenesis genes, such as tyrosinase, TRP-1, and TRP-2 was also assessed. For optimization, extraction factors such as extraction solvent, extraction time, and sample/solvent ratio were tested and optimized for maximum yield of osthol using response surface methodology with the Box-Behnken design (BBD). RESULTS: Osthol inhibits melanin content in B16F10 melanoma cells with an IC50 value of 4.9 µM. The melanogenesis inhibitory activity of osthol was achieved not by direct inhibition of tyrosinase activity but by inhibiting melanogenic enzyme expressions, such as tyrosinase, TRP-1, and TRP-2. The optimal condition was obtained as a sample/solvent ratio, 1500 mg/10 ml; an extraction time 30.3 min; and a methanol concentration of 97.7%. The osthol yield under optimal conditions was found to be 15.0 mg/g dried samples, which were well matched with the predicted value of 14.9 mg/g dried samples. CONCLUSION: These results will provide useful information about optimized extraction conditions for the development of osthol as cosmetic therapeutics to reduce skin hyperpigmentation.

Impact of Udenafil on Echocardiographic Indices of Single Ventricle Size and Function in FUEL Study Participants.

BACKGROUND: The FUEL trial (Fontan Udenafil Exercise Longitudinal) demonstrated statistical improvements in exercise capacity following 6 months of treatment with udenafil (87.5 mg po BID). The effect of udenafil on echocardiographic measures of single ventricle function in this cohort has not been studied. METHODS: The 400 enrolled participants were randomized 1:1 to udenafil or placebo. Protocol echocardiograms were obtained at baseline and 26 weeks after initiation of udenafil/placebo. Linear regression compared change from baseline indices of single ventricle systolic, diastolic and global function, atrioventricular valve regurgitation, and mean Fontan fenestration gradient in the udenafil cohort versus placebo, controlling for ventricular morphology (left ventricle versus right ventricle/other) and baseline value. RESULTS: The udenafil participants (n=191) had significantly improved between baseline and 26 weeks visits compared to placebo participants (n=195) in myocardial performance index (P=0.03, adjusted mean difference [SE] of changes between groups -0.03[0.01]), atrioventricular valve inflow peak E (P=0.009, 3.95 [1.50]), and A velocities (P=0.034, 3.46 [1.62]), and annular Doppler tissue imaging-derived peak e' velocity (P=0.008, 0.60[0.23]). There were no significant differences in change in single ventricle size, systolic function, atrioventricular valve regurgitation severity, or mean fenestration gradient. Participants with a dominant left ventricle had significantly more favorable baseline values of indices of single ventricle size and function (lower volumes and areas, E/e' ratio, systolic:diastolic time and atrioventricular valve regurgitation, and higher annular s' and e' velocity). CONCLUSIONS: FUEL participants who received udenafil demonstrated a statistically significant improvement in some global and diastolic echo indices. Although small, the changes in diastolic function suggest improvement in pulmonary venous return and/or augmented ventricular compliance, which may help explain improved exercise performance in that cohort. REGISTRATION: URL: https://clinicaltrials.gov; Unique Identifier: NCT02741115.

Changes in Retinal Structure and Function in Mice Exposed to Flickering Blue Light: Electroretinographic and Optical Coherence Tomographic Analyses

The harmful effects of blue light on the retina and health issues attributed to flickering light have been researched extensively. However, reports on the effects of flickering blue light at a frequency in the visible range on the retina are limited. This study aimed to non-invasively investigate the structural and functional changes in mice retinas following exposure to flickering blue light. BALB/c mice were subjected to non-flickering and flickering blue light, and changes in the retinal function and structure were assessed using electroretinography (ERG) and spectral-domain optical coherence tomography (SD-OCT), respectively. Retinal damage progression was monitored on days 3, 7, 14, and 42 following light exposure. Significant reductions in scotopic and photopic ERG responses were observed on day 3 (p0.05). A similar trend lasted by day 14. On day 42, however, the difference between the non-flickering and flickering groups was significant, which was corroborated by the normalized amplitudes at 0, 0.5, and 1 log cd s/ m 2 (p<0.05). Quantitative and qualitative SD-OCT assays revealed more severe and progressive retinal damage in the flickering group throughout the study. Flickering blue light causes more persistent and severe retinal damage than non-flickering blue light and may be a risk factor for retinal degeneration even at frequencies as low as 20 Hz.

A Brief Review of Anatomy Education in Korea, Encompassing Its Past, Present, and Future Direction

Anatomy is a foundational subject in medicine and serves as its language. Hippocrates highlighted its importance, while Herophilus pioneered human dissection, earning him the title of the founder of anatomy. Vesalius later established modern anatomy, which has since evolved historically. In Korea, formal anatomy education for medical training began with the introduction of Western medicine during the late Joseon Dynasty. Before and after the Japanese occupation, anatomy education was conducted in the German style, and after liberation, it was maintained and developed by a small number of domestic anatomists. Medicine in Korea has grown alongside the country’s rapid economic and social development. Today, 40 medical colleges produce world-class doctors to provide the best medical care service in the country. However, the societal demand for more doctors is growing in order to proactively address to challenges such as public healthcare issues, essential healthcare provision, regional medical service disparities, and an aging population.This study examines the history, current state, and challenges of anatomy education in Korea, emphasizing the availability of medical educators, support staff, and cadavers for gross anatomy instruction. While variations exist between Seoul and provincial medical colleges, each manages to deliver adequate education under challenging conditions. However, the rapid increase in medical student enrollment threatens to strain existing anatomy education resources, potentially compromising educational quality. To address these concerns, we propose strategies for training qualified gross anatomy educators, ensuring a sustainable cadaver supply, and enhancing infrastructure.

The Relationship Between Interoceptive Awareness, Emotion Regulation and Clinical Symptoms Severity of Depression, Anxiety and Somatization

Objective@#The primary objective of this study was to examine the associations among emotion regulation strategies, interoceptive awareness, and psychological distress measures—namely, depression, anxiety, and somatization. Additionally, we aimed to explore the predictive power of various facets of interoceptive awareness in determining the severity of symptoms for each mental disorder. @*Methods@#A cohort of 130 outpatients diagnosed with depression/anxiety disorder were recruited, and 20 subjects exhibiting incomplete responses were excluded from the dataset, leading to a final sample size of 110 outpatients. The clinical symptoms were measured by Patient Health Questionnaire-9, State–Trait Anxiety Inventory Form Y, and Symptom Checklist-90-Revised, and the usage of emotion-regulation strategies and interoceptive awareness was assessed with Emotion Regulation Questionnaire and Multidimensional Assessment of Interoceptive Awareness (MAIA), respectively. A hierarchical regression analysis was performed to examine whether emotion-regulation strategies and interoceptive awareness explain the statistically significant variance in each of the symptoms. @*Results@#In the depression model, cognitive reappraisal, accept, and attention regulation showed significant associations, while in the anxiety model, cognitive reappraisal, attention regulation, trust, and notice emerged as significant factors. Lastly, cognitive reappraisal and attention regulation were found to be significant contributors to the final model for somatization. @*Conclusion@#The inclusion of MAIA subscales improved the predictive ability of the regression model, highlighting the independent association between interoceptive awareness—particularly attention regulation—and clinical symptoms of anxiety and depression. Additionally, the study underscores the relevance of considering the specific pathological context when implementing interventions, as evidenced by the positive associations between the accept subscale and depression and between the notice subscale and anxiety, respectively.

Newly Developed Sex-Specific Z Score Model for Coronary Artery Diameter in a Pediatric Population

Background@#This study aimed to generate a Z score calculation model for coronary artery diameter of normal children and adolescents to be adopted as the standard calculation method with consensus in clinical practice. @*Methods@#This study was a retrospective, multicenter study that collected data from multiple institutions across South Korea. Data were analyzed to determine the model that best fit the relationship between the diameter of coronary arteries and independent demographic parameters. Linear, power, logarithmic, exponential, and square root polynomial models were tested for best fit. @*Results@#Data of 2,030 subjects were collected from 16 institutions. Separate calculation models for each sex were developed because the impact of demographic variables on the diameter of coronary arteries differs according to sex. The final model was the polynomial formula with an exponential relationship between the diameter of coronary arteries and body surface area using the DuBois formula. @*Conclusion@#A new coronary artery diameter Z score model was developed and is anticipated to be applicable in clinical practice. The new model will help establish a consensus-based Z score model.

Symmetric Bilateral Congenital Middle Ear Cholesteatoma: A Case Report

Congenital middle ear cholesteatoma (CMEC) accounts for 2%-5% of all cases of middle ear cholesteatoma. CMEC is rare and diagnostically challenging; therefore, only a few cases are reported in the literature, and the pathophysiology of this condition remains largely unclear. Currently, epidermoid formation, amniotic fluid contamination, lack of the tympanic ring, and squamous metaplasia are among the mechanisms implicated in the pathogenesis of CMEC; however, no single theory satisfactorily explains the pathophysiology of this disorder. We report a case of CMEC in a young male patient, who showed a symmetric, binaural whitish mass posterior to the anterosuperior quadrant of the tympanic membrane. A few reports have described bilateral CMEC; however, no study has reported symmetrical CMEC as observed in this case. Bilateral tympanoplasty concomitant with cholesteatoma removal was performed, and histopathological evaluation of the resected specimen showed closed-type cholesteatoma. In this report, we describe a rare case of symmetric CMEC, which supports the epidermoid formation theory associated with CMEC, together with a literature review.

The Usefulness of a Simplified Navigation-Based Instrumentation for a Novice Surgeon in Primary Total Knee Arthroplasty: A Retrospective Analysis of a Randomized Controlled Trial

Background@#A novel simplified navigation-based instrumentation system has been developed. It simplifies the existing navigation system and facilitates convenient bone cutting by positioning the tracker on an existing cutting block without additional pin fixation. This study aimed to compare the outcomes of this newly developed simplified navigation-based instrumentation system in primary total knee arthroplasty (TKA) performed by a novice surgeon with those of conventional surgical techniques. @*Methods@#From January 2020 to July 2020, 67 knees that underwent primary TKA using the ExactechGPS TKA Plus (group A) were compared to 68 knees that underwent primary TKA using a conventional technique (group B). All patients had a minimum follow-up of 24 months. The operative details such as tourniquet time were investigated. Postoperative hip-knee-ankle (HKA) angle and component position angles in the coronal and sagittal planes (α, β, γ, and δ angles) were evaluated. The outlier rates were compared between the groups as those lying outside ± 3°. Knee Injury and Osteoarthritis Outcome Score for Joint Replacement, the Western Ontario and McMaster Universities Osteoarthritis Index for pain and function, and range of motion were compared. @*Results@#There was no statistically significant difference in average tourniquet time between the groups (74.3 vs. 70.3 minutes, p = 0.061). Outlier rates for HKA angle (7.5% vs. 23.5%, p = 0.010) and β angle (1.5% vs. 22.1%, p < 0.001) in group A were significantly lower than those in group B. There were no significant differences in clinical outcomes between the groups. @*Conclusions@#Primary TKA performed by a novice surgeon using a simplified navigation-based instrumentation system did not significantly increase the operation time, and more accurate lower extremity mechanical alignment and tibial component alignment in the coronal plane could be obtained.

The Results of the Ultrasonographic Evaluation for the Contralateral Achilles Tendon in Patients with Acute Achilles Tendon Rupture / 대한스포츠의학회지

Purpose@#This study was performed to evaluate changes in Achilles tendon (AT) characteristics of asymptomatic tendons in patients with acute AT ruptures on the contralateral side by using ultrasonography. @*Methods@#From January 2016 to December 2018, 31 patients were enrolled. The contralateral asymptomatic ATs were assessed: (1) fluid collection of paratenon, (2) echogenicity, and (3) thickness. The ATs were divided into the distal, middle, and proximal thirds for evaluation and were assessed before the surgery, as well as at 6 weeks, 3 months, 6 months, and 12 months after the surgery. At each time, pain in the tendons was recorded. @*Results@#In all cases, it was observed that there was a hypoechoic lesion or fluid collection of the paratenon, which did not show a significant change over time. There was no significant difference in tendon thickness according to the period in the distal and proximal areas, and significant differences were observed only in the middle area (p＜ 0.05). A new pain around the tendon occurred most often at 6 weeks after surgery (eight cases of 31 cases, 25.8%). Eight cases of pain (47.1%) remained at 12 months after surgery. @*Conclusion@#In patients with acute AT rupture, ultrasonographic hypoechoic lesions or fluid collections of the paratenon were initially observed on the contralateral tendon, but this did not show significant changes over time. A significant change in tendon thickness was observed in the middle area, but this did not show a close association with pain.

Body Awareness in Patients With Depression and/or Anxiety Disorder / 신경정신의학

Objectives@#The objective of the present study was to examine whether patients with severe depression and/or anxiety show a difference in the level of body awareness compared with that of healthy controls. @*Methods@#Outpatients (n=100) with a diagnosis of moderate to severe depression and/or anxiety and 42 healthy controls were included in the study. Body awareness was assessed with the Multidimensional Assessment of Interoceptive Awareness (MAIA) scale, and other clinical characteristics like anxiety and depression were measured using the State-Trait Anxiety Inventory and Patient Health Questionnaire, respectively. The data were analyzed using ANCOVA, and statistically significant differences between the two groups in both the overall MAIA score and subscale scores were documented. @*Results@#The overall MAIA scores of patients with depression and/or anxiety were significantly lower than that of healthy subjects. Specifically, the differences found in the subscales of trust, acceptance, attention-regulation, and return-to-body were significant, whereas the differences found in the subscales of notice and mind-to-body awareness were not. @*Conclusion@#These findings imply that the ability to monitor one’s own bodily sensations and to be aware of their connection with emotional states cannot serve as a marker for psychological well-being. Rather, it may be the aspects of attentional styles and attitudes toward bodily states that play a critical role in mental health. Further analyses examining the relationships between the subscales of body awareness and other psychological variables are deemed necessary.

Risk Factors of Fixation Failure in Femoral Neck Fractures

Purpose@#Internal fixation after a femoral neck fracture (FNF) is one of the conventional treatment options for the young and active elderly patients. However, fixation failure of internal fixation is a probable complication. The treatment of fixation failure after a primary internal fixation of the FNF remains a challenge. @*Materials and Methods@#Between July 2002 and March 2017, 83 patients who underwent internal fixation after FNF were retrospectively analyzed. Radiological assessments, including Pauwels’ angle, fracture level, reduction quality, and bone union, were measured, preoperatively and postoperatively.Moreover, intraoperative variables such as time to surgery, surgical time, and estimated blood loss were also evaluated. @*Results@#The patients were divided into the fixation failure and the non-failure groups. Among the 83 patients, 17 cases (20.5%) of fixation failure after the primary internal fixation of the FNF were identi-fied. When comparing the two groups according to the radiographic data, Pauwels’ angle and the reduction quality based on Garden’s angle showed significant differences (p<0.001). Moreover, when comparing the intraoperative variables, unlike the surgical time and estimated blood loss, significant differences were noted in the time interval from injury to surgery and specifically in whether the surgery was performed within 12 hours after injury (p<0.001). @*Conclusion@#Pauwels’ angle, reduction quality, and time to surgery are the major factors that can predict the possibility of internal fixation failure of the FNF. Early and accurate anatomical reduction is needed to decrease complications after the internal fixation of the FNF.

Supra-ampullary duodenectomy in a patient with positive distal resection margin after subtotal gastrectomy for gastric cancer: a case report

Resection margin involvement after curative intent resection for gastric cancer results in a poor prognosis and deprives the patient of the chance for a cure. Reoperation to achieve an R0 status should guarantee tolerable morbidity and achievement of negative margins. We performed laparoscopic distal gastrectomy with extracorporeal Billroth II reconstruction in a 56-year-old woman with gastric cancer following neoadjuvant chemotherapy. Scattered cancer cells were observed in the proximal and distal resection margins on immunohistochemical staining for cytokeratin. Two weeks postoperatively, remnant total gastrectomy and supra-ampullary duodenectomy were performed. Before reoperation, percutaneous transhepatic gallbladder drainage and angiocatheter placement outside the ampulla of Vater (AoV) via the cystic duct were performed to avoid pancreaticoduodenectomy and to obtain the maximal distal margin. Duodenal transection was performed 1 cm above the AoV. The resected duodenum was 4 cm in length. The patient had no postoperative complications and received adjuvant chemotherapy 1 month after the reoperation.

Current clinical application of dantrolene sodium

Dantrolene sodium (DS) was first introduced as an oral antispasmodic drug. However, in 1975, DS was demonstrated to be effective for managing malignant hyperthermia (MH) and was adopted as the primary therapeutic drug after intravenous administration. However, it is difficult to administer DS intravenously to manage MH. MH is life-threatening, pharmacogenomically related, and induced by depolarizing neuromuscular blocking agents or inhalational anesthetics. All anesthesiologists should know the pharmacology of DS. DS suppresses Ca2+ release from ryanodine receptors (RyRs). RyRs are expressed in various tissues, although their distribution differs among subtypes. The anatomical and physiological functions of RyRs have also been demonstrated as effective therapeutic drugs for cardiac arrhythmias, Alzheimer’s disease, and other RyR-related diseases. Recently, a new formulation was introduced that enhanced the hydrophilicity of the lipophilic DS. The authors summarize the pharmacological properties of DS and comment on its indications, contraindications, adverse effects, and interactions with other drugs by reviewing reference articles.

Chronic exposure to dexamethasone may not affect sugammadex reversal of rocuronium-induced neuromuscular blockade: an in vivo study on rats

Background@#Chronic glucocorticoid exposure is associated with resistance to nondepolarizing neuromuscular blocking agents. Therefore, we hypothesized that sugammadex-induced recovery would occur more rapidly in subjects exposed to chronic dexamethasone compared to those who were not exposed. This study evaluated the sugammadex-induced recovery profile after neuromuscular blockade (NMB) in rats exposed to chronic dexamethasone. @*Methods@#Sprague–Dawley rats were allocated to three groups (dexamethasone, control, and pair-fed group) for the in vivo study. The mice received daily intraperitoneal dexamethasone injections (500 μg/kg) or 0.9% saline for 15 days. To achieve complete NMB, 3.5 mg/kg rocuronium was administered on the sixteenth day. The recovery time to a train-of-four ratio ≥ 0.9 was measured to evaluate the complete recovery following the sugammadex injection. @*Results@#Among the groups, no significant differences were observed in the recovery time to a train-of-four ratio ≥ 0.9 following sugammadex administration (P = 0.531). The time to the second twitch of the train-of-four recovery following rocuronium administration indicated that the duration of NMB was significantly shorter in Group D than that in Groups C and P (P = 0.001). @*Conclusions@#Chronic exposure to dexamethasone did not shorten the recovery time of sugammadex-induced NMB reversal. However, the findings of this study indicated that no adjustments to sugammadex dosage or route of administration is required, even in patients undergoing long-term steroid treatment.

Association Between Body Mass Index, Body Shape Perception and Depression in Korean Female Population: The Korean National Health and Nutrition Examination Survey / 생물치료정신의학

Objectives@#The purpose of this study was to investigate the association between body mass index (BMI) and body shape perception and depression. @*Methods@#This study was based on data from 2016, 2018, and 2020 Korean National Health and Nutrition Examination Survey (KNHANES). The subjects were 7,302 adult female aged 19 to 65. We performed chi-square test with the RaoScott correction and Logistic regression analyses to examine the association among BMI, body shape perception, and depression. @*Results@#All demographic variables such as age, household income, education, marital status, medical service satisfaction, body shape perception, medical conditions except drinking problem, smoking and physical activity were correlated with depression. The rate of depression decreased from underweight to normal weight and overweight, and increased from obesity to severe obesity (p<0.001). And people who perceived themselves thin or overweight had more depression than normal (p<0.001). @*Conclusions@#The results of this study suggest that appropriate body mass index and normal body shape perception have a positive effect on mental health.

Biomechanical analysis for different mandibular total distalization methods with clear aligners: A finite element study / 대한치과교정학회지

Objective@#The purpose of this finite element method (FEM) study was to analyze the biomechanical differences and tooth displacement patterns according to the traction direction, methods, and sites for total distalization of the mandibular dentition using clear aligner treatment (CAT). @*Methods@#A finite element analysis was performed on four FEM models using different traction methods (via a precision cut hook or button) and traction sites (mandibular canine or first premolar). A distalization force of 1.5 N was applied to the traction site by changing the direction from –30 to +30° to the occlusal plane. The initial tooth displacement and von Mises stress on the clear aligners were analyzed. @*Results@#All CAT-based total distalization groups showed an overall trend of clockwise or counterclockwise rotation of the occlusal plane as the force direction varied. Mesiodistal tipping of individual teeth was more prominent than that of bodily movements. The initial displacement pattern of the mandibular teeth was more predominant based on the traction site than on the traction method. The elastic deformation of clear aligners is attributed to unintentional lingual tipping or extrusion of the mandibular anterior teeth. @*Conclusions@#The initial tooth displacement can vary according to different distalization strategies for CAT-based total distalization. Discreet application and biomechanical understanding of traction sites and directions are necessary for appropriate mandibular total distalization.

Aspiration Pneumonia in Preterm Infants on Oral Feeds after Aspiration is Confirmed by VFSS: Case Series / 대한연하장애학회지

Premature infants often face oral feeding problems. The videofluoroscopic swallow study (VFSS) is a commonly used method to detect subglottic aspiration. However, there is no consensus to date regarding the association of aspiration observed on VFSS and incidence of aspiration pneumonia in preterm infants. This study investigated the occurrence of aspiration pneumonia in preterm infants on oral feeds after aspiration has been confirmed by VFSS. This study included 50 preterm infants who had undergone VFSS. Among them, 13 patients with no aspiration, two patients who were lost to follow-up, and nine patients with massive aspiration were excluded from the analysis. In VFSS, the frequency and amount of aspiration, nasal penetration, suck-swallow ratio, and sucking power were assessed. We analyzed 26 patients with aspiration confirmed on VFSS but who had initiated oral feeding. The frequency of aspiration (percentage of the number of aspirations to the total number of swallowing) was 10.22±3.62 (%). The mean amount of aspiration was 2.28±1.02 (%). One preterm infant, born with very low-birthweight developed aspiration pneumonia 10days after the initiation of full oral feeding. He was diagnosed with respiratory distress syndrome and had weak sucking power. In the absence of massive aspiration, most infants with aspiration confirmed on VFSS tolerated oral feeding, especially when oral feeding was partially initiated.