Sungchul Choi

Sodium hydrogen sulfide inhibits nicotine and lipopolysaccharide‐induced osteoclastic differentiation and reversed osteoblastic differentiation in human periodontal ligament cells

Although previous studies have demonstrated that hydrogen sulfide (H2S) stimulated or inhibited osteoclastic differentiation, little is known about the effects of H2S on the differentiation of osteoblasts and osteoclasts. To determine the possible bioactivities of H2S on bone metabolism, we investigated the in vitro effects of H2S on cytotoxicity, osteoblastic, and osteoclastic differentiation as well as the underlying mechanism in lipopolysaccharide (LPS) and nicotine‐stimulated human periodontal ligament cells (hPDLCs). The H2S donor, NaHS, protected hPDLCs from nicotine and LPS‐induced cytotoxicity and recovered nicotine‐ and LPS‐downregulated osteoblastic differentiation, such as alkaline phosphatase (ALP) activity, mRNA expression of osteoblasts, including ALP, osteopontin (OPN), and osteocalcin (OCN), and mineralized nodule formation. Concomitantly, NaHS inhibited the differentiation of tartrate‐resistant acid phosphatase (TRAP)‐positive osteoclasts in mouse bone marrow cells and blocked nicotine‐ and LPS‐induced osteoclastogenesis regulatory molecules, such as RANKL, OPG, M‐CSF, MMP‐9, TRAP, and cathepsin K mRNA. NaHS blocked nicotine and LPS‐induced activation of p38, ERK, MKP‐1, PI3K, PKC, and PKC isoenzymes, and NF‐κB. The effects of H2S on nicotine‐ and LPS‐induced osteoblastic and osteoclastic differentiation were remarkably reversed by MKP‐1 enzyme inhibitor (vanadate) and expression inhibitor (triptolide). Taken together, we report for the first time that H2S inhibited cytotoxicity and osteoclastic differentiation and recovered osteoblastic differentiation in a nicotine‐ and periodontopathogen‐stimulated hPDLCs model, which has potential therapeutic value for treatment of periodontal and inflammatory bone diseases. J. Cell. Biochem. 114: 1183–1193, 2013.

Three-dimensional analysis of deciduous maxillary anterior teeth using cone-beam computed tomography.

The recent introduction of cone‐beam computed tomography (CBCT) into the medical field has allowed the nondestructive investigation of internal structures at relatively low cost and radiation exposure. The accuracy of CBCT in both two and three dimensions has been demonstrated, and CBCT has been used successfully for craniofacial anatomy. Knowing the anatomical structure of deciduous teeth is essential for clinical dentistry. However, the root structure of deciduous teeth is rarely reported because of the scarcity of intact deciduous teeth without root resorption. The aim of this study was to evaluate the intact root form of deciduous teeth using CBCT. Data from 38 young children was analyzed using an image‐analyzing program. The degree of buccal dilacerations was 26.3° for deciduous maxillary central incisors (DMA), 16.5° for deciduous maxillary lateral incisors (DMB), and 17.5° for deciduous maxillary canines (DMC) in about half of the root length. The crown‐to‐root ratios were 0.52 for DMA, 0.48 for DMB, and 0.52 for DMC. These data will be helpful for understanding the development of dentition, and for clinical dentistry. Clin. Anat. 25:182–188, 2012.

Agents Used for Pediatric Dental Sedation

오늘날 소아치과 진료에 있어서 진정법은 필수 불가결한 요소로 받아들여지고 있다. 이에 대한소아치과학회는 학회원들의 보다 안전하고 효율적인 진정법 시행을 돕기 위해 진정법 위원회를 결성하고 2014년 소아치과 개원의들의 진정법 사용에 대한 실태조사를 실시 한 바 있다. 이 설문조사 결과, 진정법을 시행하는 교육 코스가 만들어 진다면 참여할 의사가 있는지에 대한 질문에 응답자의 86%가 참여의사를 밝혔으며 진정법 교육과정에서 배우고 싶은 내용으로 안전한 약물용량과 가이드라인이 2위를 차지하여 1위인 응급상황 시 대처법 다음으로 교육받고 싶은 내용으로 나타났다. 그러나 약물을 선택하고 용량을 결정하기 위해서는 여러 가지 요소를 고려해야 하므로 용량을 일률적으로 정하여 지침을 제정하는 것은 현실적으로 어려운 일이고 실제적으로도 그 어떤 진정법 지침에도 약물의 용량을 제시해 놓지는 않았다. 성공적인 진정법을 위해 소아치과의사는 각 과정마다 개별적인 치료 계획을 수립해야 하며, 각 진정제의 고유의 약효뿐 만 아니라 다른 약제들 간의 상호 작용에 대하여 충분히 숙지하는 것이 중요하다. 이 종설에서는 문헌 고찰을 통해 소아치과 임상에서 자주 사용되는 진정제들에 대한 정보를 되새기고 의사용 처방편람(Physicians Desk Reference: PDR) 및 소아치과 분야의 다양한 교과서의 추천용량을 정리하여 소개하고자 한다. 【Sedation is an indispensable part of contemporary pediatric dentistry. The Korean Academy of Pediatric Dentistry (KAPD) organized the dental sedation committee to help members perform safer and more effective sedation. The committee surveyed 111 members who practice dental sedation to figure out the present state of sedation in 2014. According to the survey, 86% of the respondents indicated that they were interested in continuing education of sedation. The most interesting topic was sedation related emergency management, followed by safe dosages of sedative drugs. However, it is not realistic to establish the recommended dosages as a guideline since the selection of agents and dosages depend on various factors. In order to provide successful sedation, pediatric dentist should make an individual sedation plan for each procedure. It is important to understand not only the properties of each sedative, but also interactions with other drugs. This article reviews useful information of commonly used agents for dental sedation and summarizes the recommended dosages from the Physicians Desk Reference (PDR) and some famous pediatric dentistry textbooks.】

Successful Conservative Surgical Treatment of Ameloblastic Fibroma in the Posterior Maxilla : A Case Report

Ameloblastic fibroma (AF) is a rare odontogenic ectomesenchymal tumor that is frequently seen in the first two decades of life, and occurs in the mandible. The most proper management of AF has been a recent topic of debate because of its recurrence and malignant transformation. This report describes AF in a 4-year-old male, which was a unilocular radiolucency on the maxillary right primary molar area with a scalloped border and corticated margin. The tumor was treated conservatively with enucleation and curettage, and the decision was made to preserve the right primary second molar. A biopsy confirmed it as AF. During the 43 months of follow-up, the patient had no evidence of recurrence or malignant transformation. Moreover, the radiographic examination revealed the generation of tooth germ to be a permanent second premolar. This report shows a case of AF in the posterior maxilla of a 4-year-old boy and discusses the conservative therapeutic approach to this tumor. Therefore, the age of the patients should be an important consideration when choosing conservative or radical surgery in a young AF patient.

A Survey of Guardian’s Attitudes toward Behavior Guidance Techniques

본 연구의 목적은 국내 실정에 맞는 행동유도법에 대한 보호자의 인식도를 조사하여 어린이 환자와 보호자, 그리고 치과 의사간의 긍정적인 관계를 설정하는데 기초 자료를 제공하는 것이다. 117명의 보호자에게 소아치과에서 사용되는 행동유도법에 대해 구두로 설명한 후 설문지를 작성하게 하였다. 설문지에 포함된 행동...

Three Dimensional Analysis of Primary Maxillary Central and Lateral Anterior Zirconia Crown

This study was performed to compare the shape and dimension of anterior zirconia crowns to other pediatric crowns using a three-dimensional scanner to investigate adequate amount of tooth preparation. Primary central and lateral anterior zirconia crowns, stainless steel crowns and celluloid strip crowns were scanned by a three-dimensional scanner. Outer and inner surfaces of zirconia and stainless steel crowns, and outer surface of celluloid strip crowns were analyzed. In outer scanned images, all sizes of central and lateral size 1 zirconia crown had the largest labiolingual diameter among the three crowns. In inner scanned images, zirconia crown`s mesiodistal diameter was 0.7-1.0 mm smaller and crown length was approximately 1 mm shorter than those of stainless steel crowns. Zirconia crown`s labiolingual diameter was larger in central crowns whereas it was smaller in lateral crowns than that of stainless steel crowns. Recommended preparation required for zirconia crown is incisal 2.5-3.0 mm, mesiodistal 1.5-2.0 mm, labial 0.5-1.0 mm. Cingulum should be trimmed parallel to the long axis. No more lingual reduction is needed in central incisors whereas additional 0.5 mm reduction is suggested in lateral incisors.

Analysis of 269 Cases of Jaw Cysts in Children and Adolescents: A Retrospective Study over a Decade

This study aimed to identify the characteristics of jaw cysts among children and adolescents treated at the Kyung Hee University Dental Hospital from 2005 to 2015. A retrospective observational study was conducted of 269 jaw cysts diagnosed in 253 patients. The following variables were recorded: gender, age, prevalence and location of lesions, clinical symptoms and treatment. Statistical analyses were performed using the SPSS (version 20.0). Our results suggest that the cysts are slightly more prevalent in males. Cystic lesions of the jaws in children are predominantly odontogenic and developmental in origin. Dentigerous cysts predominate in developmental cysts and the most frequent diagnosis is radicular cysts in inflammation cysts. The most common location of the cysts is in the mandible, particularly the lower molar region. In numerous cases, the patients have no clinical symptoms. Most cysts were surgically enucleated with tooth extraction. Furthermore, our findings demonstrate that the characteristics of jaw cysts in children are distinctive and differ in several respects from the corresponding distribution of jaw cysts in adult population. Therefore, knowledge of the clinical, radiological and histopathological behavior of jaw cysts and periodic radiographic examination are key factors for early diagnosis and adequate treatment of jaw cysts in children.

Comparison of Dental Outcomes after General Anesthesia According to the Follow-up Pattern in Special Health Care Needs Patients

Special Health Care Needs (SHCN) patients need regular follow-up because of high incidence and severity of oral disease. The aim of this study was to evaluate the dental treatment outcomes of SHCN patients according to follow-up patterns. SHCN patients who were treated under general anesthesia (GA) at Kyung Hee University Dental Hospital from 2006 to 2014 were included in this study. The final samples comprised of 53 patients that were divided into regular (33 patients) and irregular (20 patients) follow-up groups according to their follow-up patterns. The type of dental treatment after GA during the follow-up periods were compared. In the irregular group, aggressive treatment including endodontic, prosthetic treatment, and extraction were predominant, compared with the regular group (p

Minimally Invasive Surgery in a Pediatric Palatal Plasmacytoid Myoepithelioma

Myoepithelioma is a rare disease in the salivary gland. Myoepithelioma is more common in adults than in children or adolescents. An 8-years-old female patient visited our clinic with a chief complaint of a painless swelling on the palate. Conservative treatment that preserves the overlaying palatal mucosa while surgically excising the tumor was carried out under general anesthesia, because the patient was young and the size of the tumor was relatively large. The surgical wound healed well and there had not been any sign of recurrence during the regular follow-up period of 40 months. Minimally invasive surgical treatment which preserves peripheral palatal tissue can be useful in a pediatric myoepithelioma.

Predictive Factors of Ectopic Eruption of the Maxillary First Permanent Molar

In order to provide a diagnostic basis for predicting the possibility of the self-correction of ectopic first permanent molars, differences among normal eruption, reversible and irreversible ectopic eruption of maxillary first permanent molars were retrospectively analyzed. The angles of the long axes and the occlusal lines between the maxillary first permanent molar and the adjacent tooth were measured by panoramic radiographs. The occlusal relationship of second primary molars was also investigated. There is a statistically significant difference between the ectopic eruption group and normal group (p < 0.05), but not between the reversible and irreversible ectopic eruption groups (p > 0.05). The angles between the second primary molar and the first permanent molar, the second primary molar and the second permanent molar in ectopic groups showed a smaller degree than those of the control group. Mesial step was found more frequently in the ectopic eruption group than the normal group. In conclusion, the angulation of the first permanent molar and tooth germ of the maxillary second permanent molar showed close relation with ectopic eruption of the maxillary first permanent molar and ectopic first permanent molar is likely to occur in class III patients with maxillary deficiency.