Full mouth rehabilitation using 3D printed crowns and implant assisted removable partial denture for a crossed occlusion: a case report / 대한치과보철학회지

With the recent development of computer-aided design-computer-aided manufacturing technology and 3D printing technology, and the introduction of various digital techniques, the accuracy and efficiency of top-down definitive prosthetic restoration are increasing. In this clinical case, stable occlusion support was obtained through the placement of a total of 9 maxillary and mandibular posterior implants in patient with anterior-posterior crossed occlusion. The edentulous area of the maxillary anterior teeth, which showed a tendency of high resorption of the residual alveolar bone, was restored with a Kennedy Class IV implant assisted removable partial denture to restore soft tissue esthetics. Computed tomography guided surgery was used to place implants in the planned position, double scan technique was used to reflect the stabilized occlusion in the interim restoration stage to the definitive prostheses, and metal 3D printing was used to manufacture the coping and framework. This clinical case reports that efficient and predictable top-down full mouth rehabilitation was achieved using various digital technologies and techniques.

Antimicrobial activity of candidate probiotic Streptococcus salivarius against Gram-positive bacteria in oral cavity / 대한구강보건학회지

Objectives@#The aim of this study is to investigate antimicrobial activity in isolated Streptococcus salivarius against Gram-positive bacteria related oral diseases. @*Methods@#S. salivarius was used in G2, G7, K12, and ATCC 7073 strains and tryptic soy broth supplemented with glucose was cultivated. Actinomyces israelii, Actinomyces viscosus, and Enterococcus faecalis were cultivated with brain heart infusion broth. Streptococcus mutans and Streptococcus sobrinus were maintained using tryptic soy broth. The antimicrobial activity of S. salivarius was performed by minimum inhibitory concentration using the spent culture medium. @*Results@#All S. salivarius have antimicrobial activity against Gram-positive bacteria in oral cavity. When comparing antimicrobial activity, S. salivarius G2 and G7 as isolated strain showed stronger antimicrobial activity against Gram-positive microbe than type K12 strain. @*Conclusions@#S. salivarius G2 and G7 have strong antimicrobial activity and may be prevent oral disease by Gram-positive bacteria in oral cavity.

Heme effects of hemin on growth of peridontopathogens

Purpose@#The purpose of this study was to investigate effect of heme on periodontopathogens. Materials and Methods: The experiment was performed using 7 types of anaerobic bacteria present in the periodontal pocket. The bacteria were cultured using suitable medium in an anaerobic condition with or without hemin, and the growth of the bacteria was measured every 6 hours by a spectrophotometer. @*Results@#the growth of Porphyromonas gingivalis was different only by the presence or absence of hemin. The growth of other periodontopathogens except Treponema denticola was different in a hemin concentration-dependent manner. The growth of T. denticola was interfered by hemin. @*Conclusion@#Heme may be a factor that leads dysbiosis in the microbial ecosystem of the subgingival plaque and thereby promote a periodontitis-causing environment.

Characteristics of antimicrobial activity of Streptococcus salivarius K12by culture condition

Purpose@#The purpose of this study was to examine effects of culture conditions on the growth and antibacterial activity of Streptococcus salivarius K12. @*Materials and Methods@#S. salivarius K12 was cultivated in medium containing animal and plant protein or in medium of neutral and acidic conditions. The growth of S. salivarius K12 was measured every 2 hours by a spectrophotometer. The antimicrobial activity of S. salivarius K12 against Streptococcus mutans and Porphyromonas gingivalis was investigated by the susceptibility assay using the spent culture medium. @*Results@#the growth of S. salivarius K12 showed faster in medium containing plant protein and neutral pH condition. The antimicrobial and antifungal activity of S. salivarius K12 appeared stronger in medium containing plant protein than animal proteins. @*Conclusion@#For application of S. salivarius K12 to bacterial oral disease, co-substances may be needed for S. salivarius K12 to colonize in the oral cavity and enhance the antimicrobial activity.

Neuronal Autophagy: Characteristic Features and Roles in Neuronal Pathophysiology

Autophagy is an important degradative pathway that eliminates misfolded proteins and damaged organelles from cells. Autophagy is crucial for neuronal homeostasis and function. A lack of or deficiency in autophagy leads to the accumulation of protein aggregates, which are associated with several neurodegenerative diseases. Compared with non-neuronal cells, neurons exhibit rapid autophagic flux because damaged organelles or protein aggregates cannot be diluted in post-mitotic cells; because of this, these cells exhibit characteristic features of autophagy, such as compartment-specific autophagy, which depends on polarized structures and rapid autophagy flux. In addition, neurons exhibit compartment-specific autophagy, which depends on polarized structures. Neuronal autophagy may have additional physiological roles other than amino acid recycling. In this review, we focus on the characteristics and regulatory factors of neuronal autophagy. We also describe intracellular selective autophagy in neurons and its association with neurodegenerative diseases.

Upper Extremity Deep Vein Thrombosis After Botulinum Toxin Injection: A Case Report

Botulinum toxin (BoNT) injection is widely used to improve spasticity. However, after the treatment, the patient may experience pain, inflammation, swelling and redness at the injection site. In this case, we addressed deep vein thrombosis (DVT) after BoNT treatment of the upper limb. A male aged 37 years had spasticity and dystonia in his left upper extremity. BoNT-A 100 U was injected into the left biceps brachii and an equal amount into the brachialis to relieve spasticity. After three days, he developed redness and painful swelling in the left upper arm and the next day, through the upper extremity computed tomography venography, DVT was identified in the left cephalic vein. The thrombus resolved after the anticoagulation therapy with rivaroxaban (Xarelto). We hypothesized the role of mainly three mechanisms in the development of DVT in this case: repetitive strenuous activity, relative stasis due to reduced muscle tone, and possible direct mechanical damage to the vessel wall.

Upper Extremity Deep Vein Thrombosis After Botulinum Toxin Injection: A Case Report

Botulinum toxin (BoNT) injection is widely used to improve spasticity. However, after the treatment, the patient may experience pain, inflammation, swelling and redness at the injection site. In this case, we addressed deep vein thrombosis (DVT) after BoNT treatment of the upper limb. A male aged 37 years had spasticity and dystonia in his left upper extremity. BoNT-A 100 U was injected into the left biceps brachii and an equal amount into the brachialis to relieve spasticity. After three days, he developed redness and painful swelling in the left upper arm and the next day, through the upper extremity computed tomography venography, DVT was identified in the left cephalic vein. The thrombus resolved after the anticoagulation therapy with rivaroxaban (Xarelto). We hypothesized the role of mainly three mechanisms in the development of DVT in this case: repetitive strenuous activity, relative stasis due to reduced muscle tone, and possible direct mechanical damage to the vessel wall.

Polishing characteristics of polyetherketoneketone on Candida albicans adhesion / 대한치과보철학회지

Purpose@#To compare the polishing characteristics and their influence on Candida albicans adhesion to the recently introduced polyetherketoneketone (PEKK) and the conventional polymethylmethacrylate (PMMA) denture resin material. @*Materials and methods@#Specimens from PEKK (Group E) and PMMA (Group M) were made in dimensions of 8 mm in diameter and 2 mm in thickness. The specimens were further divided into sub-groups according to the extent of polishing (ER, MR: rough; EP, MP: polished, N = 12 each). The specimens were polished using polishing machine and SiC foil. ER and MR group specimens were polished with 600 grit SiC foil only. EP and MP groups were further polished with 800, 1,000, 1,200 grit SiC foils sequentially. To measure the surface roughness values (Sa) of specimens, atomic force microscope (AFM) was used and scanning electron microscope (SEM) observation under 1,000, and 20,000 magnifications was performed to investigate surface topography. The polished specimens were soaked in C. albicans suspension for 2 hours with shaking to promote adhesion. The attached C. albicans were detached from the surface with 10 times of pipetting. The suspension of detached C. albicans was performed by serial dilution to 103 times, and the diluted suspensions were inoculated on Sabouraud dextrose agar plates using spread plate method. After incubating the plate for 48 hours, colony forming unit (CFU)/plate of C. albicans was counted. Statistical analysis was performed using one-way ANOVA and Tukey HSD test to confirm significant difference between the groups (α=.05). @*Results@#Average Sa value was significantly higher in MR group compared to other groups (P<.05), meaning that additional polishing steps reduced surface roughness effectively only in the PMMA specimens. There was no significant difference in Sa values between MP and EP groups. In SEM images, PEKK specimens showed numerous spikes of abraded material protruding from the surface and this phenomenon was more significant in EP group. The mean CFU/plate value was the highest in EP group and this was significant when it was compared to MP group (P<.05) which was the lowest. @*Conclusion@#Polishing PEKK using serial SiC abrasive foil may result in higher adhesion of C. albicans. In clinic, this should be considered carefully.

Epigenetically Upregulated T-Type Calcium Channels Contribute to Abnormal Proliferation of Embryonic Neural Progenitor Cells Exposed to Valproic Acid

Valproic acid is a clinically used mood stabilizer and antiepileptic drug. Valproic acid has been suggested as a teratogen associated with the manifestation of neurodevelopmental disorders, such as fetal valproate syndrome and autism spectrum disorders, when taken during specific time window of pregnancy. Previous studies proposed that prenatal exposure to valproic acid induces abnormal proliferation and differentiation of neural progenitor cells, presumably by inhibiting histone deacetylase and releasing the condensed chromatin structure. Here, we found valproic acid up-regulates the transcription of T-type calcium channels by inhibiting histone deacetylase in neural progenitor cells. The pharmacological blockade of T-type calcium channels prevented the increased proliferation of neural progenitor cells induced by valproic acid. Differentiated neural cells from neural progenitor cells treated with valproic acid displayed increased levels of calcium influx in response to potassium chloride-induced depolarization. These results suggest that prenatal exposure to valproic acid up-regulates T-type calcium channels, which may contribute to increased proliferation of neural progenitor cells by inducing an abnormal calcium response and underlie the pathogenesis of neurodevelopmental disorders.

Differences of Spinal Curvature, Thoracic Mobility, and Respiratory Strength Between Chronic Neck Pain Patients and People Without Cervical Pain

Objective@#To investigate the differences of spinal curvature, thoracic sagittal mobility, and respiratory strength between patients with chronic neck pain (CNP) and people without cervical pain, and to determine the correlation between respiratory strength and thoracic mobility in CNP patients. @*Methods@#A total of 78 participants were finally included in this study, of whom 30 had no cervical pain and 48 had CNP. The Neck Disability Index (NDI), cervical lordotic curvature, thoracic kyphotic curvature, thoracic sagittal range of motion (ROM), maximal inspiratory pressure (MIP), and maximal expiratory pressure (MEP) were measured and analyzed. @*Results@#In males, thoracic sagittal ROMMEP-MIP and MEP showed a significant difference between the no cervical pain group and the CNP group. In females, thoracic kyphotic curvature, thoracic sagittal ROMMEP-MIP, MIP, and MEP were significantly different between the no cervical pain group and the CNP group. Thoracic kyphotic curvature was significantly correlated with MEP and MIP in all population groups, and significantly correlated with NDI in the female group. Thoracic sagittal ROMMEP-MIP had a significant linear relationship with NDI, MEP, and MIP in all population groups. @*Conclusion@#The thoracic mobility during forced respiration was reduced in patients with CNP and was correlated with respiratory strength. Changes in the biomechanics of the cervicothoracic spine and rib cage due to CNP may contribute to impairment of respiratory strength.

Corrigendum to: Dual mechanisms for the regulation of brain-derived neurotrophic factor by valproic acid in neural progenitor cells

The authors note that on page 685, the acknowledgement of “This study was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST) (No. 2017R1D1A1B03031920),” should instead appear as “This study was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST) (No. 2017R1D1A1B03031920) and Chung-Ang University Research Grants in 2017.”

Mannosylerythritol lipids ameliorate ultraviolet A-induced aquaporin-3 downregulation by suppressing c-Jun N-terminal kinase phosphorylation in cultured human keratinocytes

Mannosylerythritol lipids (MELs) are glycolipids and have several pharmacological efficacies. MELs also show skin-moisturizing efficacy through a yet-unknown underlying mechanism. Aquaporin-3 (AQP3) is a membrane protein that contributes to the water homeostasis of the epidermis, and decreased AQP3 expression following ultraviolet (UV)-irradiation of the skin is associated with reduced skin moisture. No previous study has examined whether the skin-moisturizing effect of MELs might act through the modulation of AQP3 expression. Here, we report for the first time that MELs ameliorate the UVA-induced downregulation of AQP3 in cultured human epidermal keratinocytes (HaCaT keratinocytes). Our results revealed that UVA irradiation decreases AQP3 expression at the protein and messenger RNA (mRNA) levels, but that MEL treatment significantly ameliorated these effects. Our mitogen-activated protein kinase inhibitor analysis revealed that phosphorylation of c-Jun N-terminal kinase (JNK), but not extracellular signal-regulated kinase or p38, mediates UVA-induced AQP3 downregulation, and that MEL treatment significantly suppressed the UVA-induced phosphorylation of JNK. To explore a possible mechanism, we tested whether MELs could regulate the expression of peroxidase proliferator-activated receptor gamma (PPAR-γ), which acts as a potent transcription factor for AQP3 expression. Interestingly, UVA irradiation significantly inhibited the mRNA expression of PPAR-γ in HaCaT keratinocytes, whereas a JNK inhibitor and MELs significantly rescued this effect. Taken together, these findings suggest that MELs ameliorate UVA-induced AQP3 downregulation in HaCaT keratinocytes by suppressing JNK activation to block the decrease of PPAR-γ. Collectively, our findings suggest that MELs can be used as a potential ingredient that modulates AQP3 expression to improve skin moisturization following UVA irradiation-induced damage.

T-Type Calcium Channels Are Required to Maintain Viability of Neural Progenitor Cells

T-type calcium channels are low voltage-activated calcium channels that evoke small and transient calcium currents. Recently, T-type calcium channels have been implicated in neurodevelopmental disorders such as autism spectrum disorder and neural tube defects. However, their function during embryonic development is largely unknown. Here, we investigated the function and expression of T-type calcium channels in embryonic neural progenitor cells (NPCs). First, we compared the expression of T-type calcium channel subtypes (CaV3.1, 3.2, and 3.3) in NPCs and differentiated neural cells (neurons and astrocytes). We detected all subtypes in neurons but not in astrocytes. In NPCs, CaV3.1 was the dominant subtype, whereas CaV3.2 was weakly expressed, and CaV3.3 was not detected. Next, we determined CaV3.1 expression levels in the cortex during early brain development. Expression levels of CaV3.1 in the embryonic period were transiently decreased during the perinatal period and increased at postnatal day 11. We then pharmacologically blocked T-type calcium channels to determine the effects in neuronal cells. The blockade of T-type calcium channels reduced cell viability, and induced apoptotic cell death in NPCs but not in differentiated astrocytes. Furthermore, blocking T-type calcium channels rapidly reduced AKT-phosphorylation (Ser473) and GSK3β-phosphorylation (Ser9). Our results suggest that T-type calcium channels play essential roles in maintaining NPC viability, and T-type calcium channel blockers are toxic to embryonic neural cells, and may potentially be responsible for neurodevelopmental disorders.

Effects of Several Cosmetic Preservatives on ROS-Dependent Apoptosis of Rat Neural Progenitor Cells

Benzalkonium chloride, diazolidinyl urea, and imidazolidinyl urea are commonly used preservatives in cosmetics. Recent reports suggested that these compounds may have cellular and systemic toxicity in high concentration. In addition, diazolidinyl urea and imidazolidinyl urea are known formaldehyde (FA) releasers, raising concerns for these cosmetic preservatives. In this study, we investigated the effects of benzalkonium chloride, diazolidinyl urea, and imidazolidinyl urea on ROS-dependent apoptosis of rat neural progenitor cells (NPCs) in vitro. Cells were isolated and cultured from embryonic day 14 rat cortices. Cultured cells were treated with 1–1,000 nM benzalkonium chloride, and 1–50 μM diazolidinyl urea or imidazolidinyl urea at various time points to measure the reactive oxygen species (ROS). PI staining, MTT assay, and live-cell imaging were used for cell viability measurements. Western blot was carried out for cleaved caspase-3 and cleaved caspase-8 as apoptotic protein markers. In rat NPCs, ROS production and cleaved caspase-8 expression were increased while the cell viability was decreased in high concentrations of these substances. These results suggest that several cosmetic preservatives at high concentrations can induce neural toxicity in rat brains through ROS induction and apoptosis.

Dual mechanisms for the regulation of brain-derived neurotrophic factor by valproic acid in neural progenitor cells

Autism spectrum disorders (ASDs) are neurodevelopmental disorders that share behavioral features, the results of numerous studies have suggested that the underlying causes of ASDs are multifactorial. Behavioral and/or neurobiological analyses of ASDs have been performed extensively using a valid model of prenatal exposure to valproic acid (VPA). Abnormal synapse formation resulting from altered neurite outgrowth in neural progenitor cells (NPCs) during embryonic brain development has been observed in both the VPA model and ASD subjects. Although several mechanisms have been suggested, the actual mechanism underlying enhanced neurite outgrowth remains unclear. In this study, we found that VPA enhanced the expression of brain-derived neurotrophic factor (BDNF), particularly mature BDNF (mBDNF), through dual mechanisms. VPA increased the mRNA and protein expression of BDNF by suppressing the nuclear expression of methyl-CpG-binding protein 2 (MeCP2), which is a transcriptional repressor of BDNF. In addition, VPA promoted the expression and activity of the tissue plasminogen activator (tPA), which induces BDNF maturation through proteolytic cleavage. Trichostatin A and sodium butyrate also enhanced tPA activity, but tPA activity was not induced by valpromide, which is a VPA analog that does not induce histone acetylation, indicating that histone acetylation activity was required for tPA regulation. VPA-mediated regulation of BDNF, MeCP2, and tPA was not observed in astrocytes or neurons. Therefore, these results suggested that VPA-induced mBDNF upregulation was associated with the dysregulation of MeCP2 and tPA in developing cortical NPCs.

Retrospective study on marginal bone resorption around immediately loaded implants / 대한치과보철학회지

PURPOSE: Patients who treated implant immediate loading within a week after implant placement at Wonkwang University Dental Hospital Implant Center were evaluated marginal bone resorption. These retrospective analyses are intended to reinforce the clinical evidence for the implant immediate loading. MATERIALS AND METHODS: Medical history and radiographic data were investigated, which were the patients' who treated implant immediate loading and restoration with provisional prostheses between January 2005 and June 2016, at Wonkwang University Dental Hospital Implant Center. Total number of implants was 70, marginal bone resorption was measured according to implant length, diameter and connection type. To measure marginal bone resorption, periapical radiographs were taken when the implants were placed and after 6 month. Statistical analysis was done in Mann-whitney U test and Kruskal-wallis test with SPSS 22.0 software (P < .05). RESULTS: Mean marginal bone resorption around immediately loaded implants according to implant connection type was shown 1.24 ± 0.72 mm in internal hexagon connection type and 1.73 ± 1.27 mm in external hexagon connection type. There was no statically significant difference in marginal bone resorption with implant length and diameter. CONCLUSION: Implants with immediated loading in internal hexagon connection type showed less marginal bone resorption significantly than in external hexagon connection type.

Compensatory Technique Using Therapeutic Band for Dysphagia / 대한연하장애학회지

A 63-year-old man visited outpatient clinic complaining of dysphagia due to left jugular foramen meningioma. The patient underwent conventional dysphagia rehabilitation programs but functional improvement was not enough. A videofluoroscopic swallowing study (VFSS) revealed decreased laryngeal elevation and a lot of residue in pyriform sinus and vallecula. We noticed that enhancing laryngeal elevation like mendelshon maneuver promotes functional compensation, so we developed a therapeutic band for promoting laryngeal elevation. In follow-up VFSS, swallowing function was improved on the band. Persistent dysphagia due to decreased laryngeal elevation is very common and this case showed the possibility of improvement of symptom using therapeutic band we devleoped with conventional dysphagia rehabilitation programs.

Comparison of Biometric Measurements and Refractive Results among Low-coherence Reflectometry, Partial Interferometry and Applanation Ultrasonography

PURPOSE: To compare the measurement results and the accuracy of the predicted refractive error after cataract surgery among 3 ocular biometry devices; OA-2000®, IOL Master® and A-scan ultrasound in posterior subscapular cataracts. METHODS: Biometry measurements including axial length, anterior chamber depth and the keratometry of 80 cataractous eyes were measured using ultrasonography, OA-2000® and IOL Master®. To calculate the intraocular lens (IOL) power, the SRK/T formula was used and 3 months after cataract surgery, the refractive outcome was compared to the preoperatively predicted refractive error. RESULTS: The number of eyes measured by the 3 devices (A-scan, IOL Master® and OA-2000®) was 57 (group A) and the number of eyes measured by 2 devices (A-scan and OA-2000®) was 22 (group B). When cataract grading was performed based on the Lens Opacity Classification system III, the severity of posterior subscapular opacity was significantly different between the 2 groups (p = 0.001). Although no difference was observed in the measured biometry values including axial length, anterior chamber depth and keratometry in groups A and B, the predicted refractive error was significantly different in group B; OA-2000® showed a significantly higher accuracy in predicting IOL power than A-scan. CONCLUSIONS: In cataract patients whose posterior subscapular opacity is not severe, the accuracy for predicting refractive error after cataract surgery was not significantly different among the 3 devices included in our study (A-scan, IOL Master® and OA-2000®). However, in patients with severe posterior subscapular opacity, OA-2000®, that provides a Fourier domain light source-calculated predicted refractive error of IOL may be more accurate.

Intramuscular Hematoma Following Radial Extracorporeal Shockwave Therapy for Chronic Neurogenic Heterotopic Ossification: A Case Report

Extracorporeal shockwave therapy (ESWT) has been reported to be a safe and effective method for decreasing pain and relieving range of motion (ROM) limitations caused by neurogenic heterotopic ossification (NHO), though there has been no report that it might cause hematoma if applied to NHO. We hereby report a case of massive hematoma after ESWT, specifically the radial shockwave therapy (RSWT) device at both hips in a 49-year-old female patient with NHO. She had developed NHO after extensive subarachnoid hemorrhage. We had applied RSWT according to the previous report. The pain and the ROM limitations were gradually improved. Six weeks later, she reported pain and ROM limitations on the right hip. From a medial aspect, swelling and bruising of the right thigh could be seen. Magnetic resonance imaging and ultrasonography suggested a large hematoma between right hip adductor muscles. The symptoms disappeared after conservative treatment for one month, and subsequent follow-up imaging studies demonstrated resolution of the hematoma.

Valproic Acid Induces Telomerase Reverse Transcriptase Expression during Cortical Development

The valproic acid (VPA)-induced animal model is one of the most widely utilized environmental risk factor models of autism. Autism spectrum disorder (ASD) remains an insurmountable challenge among neurodevelopmental disorders due to its heterogeneity, unresolved pathological pathways and lack of treatment. We previously reported that VPA-exposed rats and cultured rat primary neurons have increased Pax6 expression during post-midterm embryonic development which led to the sequential upregulation of glutamatergic neuronal markers. In this study, we provide experimental evidence that telomerase reverse transcriptase (TERT), a protein component of ribonucleoproteins complex of telomerase, is involved in the abnormal components caused by VPA in addition to Pax6 and its downstream signals. In embryonic rat brains and cultured rat primary neural progenitor cells (NPCs), VPA induced the increased expression of TERT as revealed by Western blot, RT-PCR, and immunostainings. The HDAC inhibitor property of VPA is responsible for the TERT upregulation. Chromatin immunoprecipitation revealed that VPA increased the histone acetylation but blocked the HDAC1 binding to both Pax6 and Tert genes. Interestingly, the VPA-induced TERT overexpression resulted to sequential upregulations of glutamatergic markers such as Ngn2 and NeuroD1, and inter-synaptic markers such as PSD-95, α-CaMKII, vGluT1 and synaptophysin. Transfection of Tert siRNA reversed the effects of VPA in cultured NPCs confirming the direct involvement of TERT in the expression of those markers. This study suggests the involvement of TERT in the VPA-induced autistic phenotypes and has important implications for the role of TERT as a modulator of balanced neuronal development and transmission in the brain.