Kyung-Gyun Hwang

The effect of mineral trioxide aggregate on odontogenic differentiation in dental pulp stem cells.

INTRODUCTION This study aimed to identify the early genetic changes related to odontogenic differentiation when mineral trioxide aggregate (MTA) is applied to dental pulp stem cells (DPSCs). METHODS Odontogenic-differentiated cells (induced DPSCs) were obtained by culturing DPSCs in odontoinduction medium for 14 days. Thereafter, MTA in Teflon tubes was applied to the induced DPSCs and uninduced cells. Cells exposed to empty tubes were used as negative controls. The total RNA was extracted from the MTA treated and MTA untreated cells 1 and 3 days after tube application and assessed by microarray analysis. The key results were confirmed selectively by reverse-transcription polymerase chain reaction. We also performed a gene set enrichment analysis. RESULTS In microarray analysis, although the expression levels of 460 genes were changed more than 2-fold in MTA-treated, uninduced DPSCs after 1 day, only 39 genes were altered in MTA-treated, induced DPSCs. In the odontoinduction medium-induced, MTA-treated DPCs, the value of correlation was 0.993 on 1 day and 0.986 on 3 day compared with 0.970 on 1 day and 0.975 on 3 day in the uninduced, MTA-treated DPSCs. Gene set enrichment analysis revealed that MTA significantly up-regulated gene sets involved in cell migration, the response to transforming growth factor β1, and the inflammation pathway in the uninduced DPSCs, whereas in the induced DPSCs it only up-regulated genes involved in cell migration after 1 day. CONCLUSIONS This result shows that MTA stimulates the odontogenic differentiation of DPSCs, and the effects of MTA are drastically increased in uninduced pulp cells compared with odontogenic-differentiated cells.

Postoperative Stability After Sagittal Split Ramus Osteotomies for a Mandibular Setback With Monocortical Plate Fixation or Bicortical Screw Fixation

PURPOSE This comparative study was performed to analyze mandibular stability after bilateral sagittal split ramus osteotomies for a mandibular setback with a monocortical plate fixation or bicortical screw fixation. PATIENTS AND METHODS A total of 60 patients with a skeletal Class III malocclusion who underwent sagittal split osteotomies and mandibular setback were included in the present study. Among the patients, 30 were osteosynthesized monocortically with a titanium plate, while the other 30 were osteosynthesized bicortically with positioning screws. This retrospective study used cephalometric radiographs taken preoperatively (T0), and at 1 week (T1), 3 months (T2), and 1 year (T3) postoperatively. The linear and angular changes of the cephalometric landmarks of the chin region were measured at each time period, and the changes of each cephalometric landmark were determined for 4 different time intervals: T0 to T1 (Delta T1), T1 to T2 (Delta T2), T2 to T3 (Delta T3), and T0 to T3 (Delta T4). Postoperative changes in mandibular shape were analyzed using a paired t test to determine the stability of fixation methods. RESULTS The surgical changes (Delta T1) could be characterized as posterior movements of the mandibular body and posterosuperior movements of the chin landmark. The results of the cephalometric analysis at 3 and 12 months postsurgery (Delta T2 and Delta T3) could be characterized as anterosuperior movements of the mandible. In both treatment groups, surgical changes were relatively well maintained. Likewise, analysis of the horizontal and vertical movements of the chin landmarks indicated a similar tendency in both groups. There were no statistically significant differences between the measurements of postoperative changes at each time period after surgery. CONCLUSIONS The findings of our study suggest that there were no significant differences in postoperative changes in mandibular shape in both the monocortical and bicortical fixation groups after sagittal split ramus osteotomy. We concluded that monocortical osteosynthesis using a miniplate could be used to obtain stable postoperative changes after mandibular setback.

Factors for Maxillary Sinus Volume and Craniofacial Anatomical Features in Adults With Chronic Rhinosinusitis

OBJECTIVES To compare the volume of the maxillary sinus, dental factors, and craniofacial anatomical features between control subjects and patients with chronic rhinosinusitis (CRS) and to investigate critical factors for the volumetric change in the maxillary sinus in adults. DESIGN Retrospective case-control study. SETTING Tertiary referral center. PARTICIPANTS Ninety-nine individuals who visited an allergy and sinus center: 52 control subjects (septal deviation; mean age, 32.69 years) and 47 patients with CRS (mean age, 44.43 years). INTERVENTION Cephalometry and computed tomography were performed in all the participants. In blinded tests, dentists investigated the dental status of both groups. MAIN OUTCOME MEASURES Maxillary sinus: bone thickness and volume on computed tomography; craniofacial anatomical features: linear and angular variables in lateral cephalometry; and dental evaluation: malocclusion class, teeth status, and alveolar bone height. RESULTS Bony wall thickness of the maxillary sinus significantly increased in patients with CRS (P < .001) but showed no relationship with maxillary sinus volume. Maxillary sinus volume significantly decreased in patients with CRS (P = .001). Age and alveolar bone height had a negative effect on maxillary sinus volume in both groups. Abnormal teeth had no relationship with maxillary sinus volume in both groups but showed a negative effect on alveolar bone height in the CRS group (P = .02). Class II malocclusion associated with anterior movement of the maxilla significantly increased in the CRS group (P = .006). CONCLUSIONS Regardless of CRS, maxillary sinus volume decreased with older age and increased with alveolar bone loss. Regarding craniofacial anatomical features, CRS may have an effect on malocclusion in adults.

Sialadenitis Without Sialolithiasis Treated by Sialendoscopy

PURPOSE The aim of the present study was to evaluate the effectiveness of interventional sialendoscopy in the management of non-stone obstructive sialadenitis. PATIENTS AND METHODS In the present retrospective study, we assessed the treatment outcomes of 51 patients (34 women and 17 men) who had been diagnosed with sialadenitis without salivary duct stones. The included patients had an obstructive duct condition coupled with recurrent episodes of swelling or pain in a major salivary gland. The patients who had a sialolith detected during the sialendoscopic procedure or by preoperative imaging were excluded from the present study. The outcomes assessment was based on successful removal of the obstructive etiology during the endoscopic procedure and the absence of clinical symptoms after 6 months. The involved glands included 16 submandibular glands and 35 parotid glands. RESULTS The sialendoscopic navigation was successful in 43 of 51 patients (84%). Of the 43 patients, 37 (86%) were free of symptoms from the obstructive gland after the endoscopic procedure. Of the 6 patients who were still symptomatic after the procedure, 5 had involvement of the parotid gland. Finally, 1 of the original 37 symptom-free patients developed recurrent symptoms and denied additional treatment, resulting in 36 of 43 patients (84%) remaining asymptomatic 6 months after endoscopic navigation. CONCLUSION The outcomes of the present study suggest that interventional sialendoscopy can provide symptomatic improvement in most subjects. Clinicians should consider sialendoscopy as a useful and minimally invasive procedure to treat sialadenitis without sialolithiasis.

Miniscrew-anchored alveolar distraction for the treatment of the ankylosed maxillary central incisor

This report presents the case of a 20-year-old female patient exhibiting an infraoccluded ankylosed maxillary central incisor that was avulsed and replanted after traumatic injury during childhood. To reposition the osseous and gingival margins of the ankylosed tooth to an ideal level, a new alveolar distraction device that uses anchoring miniscrews with a single tooth dento-osseous osteotomy was fabricated and the ankylosed tooth was successfully treated with exceptional patient compliance.

Gingival Metastasis from Gastric Adenocarcinoma

The oral cavity is a rare but occasional target for metastases, which may masquerade as various benign and inflammatory lesions. Also, occult cancer may metastasize to the oral cavity as a first and exclusive manifestation. It is important to bear these possibilities in mind because such situations may be encountered during a routine examination of the head and neck region. A 58-year-old man was referred to the Department of Dentistry/Oral and Maxillofacial Surgery because of a 2-month history of a painful swelling of upper right first molar area. Past medical history was significant for subtotal gastrectomy for adenocarcinoma of the stomach (stage IIIa: T3 N1 M0) at the age of 54. Following surgery, he received six cycles of chemotherapy with 5-fluorouracil, adriamycin, and mitomycin-C. At that time, no metastasis was found on abdominal computed tomography (CT) scan. Six months later, abdominal CT and endoscopic examination showed no recurrence or metastasis. However, 4 years later, pulmonary and hepatic metastases appeared, and whole body bone scan detected multiple metastatic rib, pelvis, and femoral bone lesions. Consequently, the patient was admitted for chemotherapy and referred to our department during the chemotherapy. Clinically, intraoral examination revealed soft tissue swelling, resembling periodontal pyogenic abscess of granuloma-like hyperplastic lesions. The lesion was located on the buccal gingiva and vestibule and measured approximately 3.0 2.0 cm (Fig 1A). The exophytic growth, in the first and second molar region, was associated with pain, foul odor, and a bloody and necrotic tag. The extraoral head and neck examination showed no evidence of lymphadenopathy or other pathology. Radiographic examination demonstrated horizontal bone loss in the first and second molar region. Facial CT showed a 2.0 1.5-cm soft tissue mass on the lateral right maxilla near the second molar. The bony defect was found on the inferior-lateral wall of the right maxillary sinus. However, there was no change on the sinus mucosa (Fig 1B). After the patient was provided written informed consent, the incisional biopsy was performed to confirm clinical diagnosis of this gingival mass. Histopathologically, biopsy

Lemierre's Syndrome Originated from the Odontogenic Infection: A Case Report

Also called necrobacillosis or postanginal sepsis, Lemierre’s syndrome (LS) is an uncommon but potentially lethal complication of odontogenic infection. A 27-year-old male diagnosed with Ludwig’s angina was transferred from a local hospital due to continuous fever and chills after incision and drainage under general anesthesia. The swelling of both submental and submandibular area subsided, but the fever and chills persisted. While generalized malaise improved, sepsis developed together with the deterioration of liver function. The chest computed tomography scan revealed multiple cavitations throughout both lungs, which were diagnosed as septic pulmonary embolism. After consulting the department of infectious diseases, the patient was treated with intravenous antibiotics focusing on vancomycin and additional antibiotics. After 3 weeks of treatment, the patient recovered completely. Despite its decreased mortality, dentists are not familiar with LS, and it is diffi cult to diagnose correctly. In this paper, we report a case and present a review of literature.

Preliminary evaluation of a three-dimensional, customized, and preformed titanium mesh in peri-implant alveolar bone regeneration

Objectives The purpose of this preliminary study is to evaluate the effectiveness of a customized, three-dimensional, preformed titanium mesh as a barrier membrane for peri-implant alveolar bone regeneration. Materials and Methods Ten patients were recruited for this study. At the time of implant placement, all patients had fenestration or a dehiscence defect around the implant fixture. A mixture of particulate intraoral autologous bone and freeze-dried bone allograft was applied to the defect in a 1 : 1 volume ratio and covered by the preformed titanium mesh. A core biopsy specimen was taken from the regenerated bone four months postoperatively. Patients were followed for 12 months after the definitive prosthesis was placed. Results Satisfactory bone regeneration with limited fibrous tissue was detected beneath the preformed titanium mesh. Histologic findings revealed that newly formed bones were well-incorporated into the allografts and connective tissue. New growth was composed of approximately 80% vital bone, 5% fibrous marrow tissue, and 15% remaining allograft. All implants were functional without any significant complications. Conclusion The use of preformed titanium mesh may support bone regeneration by maintaining space for new bone growth through its macro-pores. This preliminary study presents the efficacy of a preformed titanium mesh as a ready-to-use barrier membrane around peri-implant alveolar bone defect. This preformed mesh is also convenient to apply and to remove.

Analysis of gene expression during odontogenic differentiation of cultured human dental pulp cells

Objectives We analyzed gene-expression profiles after 14 day odontogenic induction of human dental pulp cells (DPCs) using a DNA microarray and sought candidate genes possibly associated with mineralization. Materials and Methods Induced human dental pulp cells were obtained by culturing DPCs in odontogenic induction medium (OM) for 14 day. Cells exposed to normal culture medium were used as controls. Total RNA was extracted from cells and analyzed by microarray analysis and the key results were confirmed selectively by reverse-transcriptase polymerase chain reaction (RT-PCR). We also performed a gene set enrichment analysis (GSEA) of the microarray data. Results Six hundred and five genes among the 47,320 probes on the BeadChip differed by a factor of more than two-fold in the induced cells. Of these, 217 genes were upregulated, and 388 were down-regulated. GSEA revealed that in the induced cells, genes implicated in Apoptosis and Signaling by wingless MMTV integration (Wnt) were significantly upregulated. Conclusions Genes implicated in Apoptosis and Signaling by Wnt are highly connected to the differentiation of dental pulp cells into odontoblast.

The effect of gender between the oral symptoms experience and health behavior factors

Objectives: The purpose of the study was to investigate the effect of gender in the association between the oral symptoms experience and health behavior. Methods: The subjects were 54,219 adolescents selected from the web-based survey of the 11th (2015) Korean Youth Risk Behavior of Korean Center for Disease Control. Data were analyzed using SPSS 18.0. The subjects consisted of 27,198 male students(50.2%) and 27,021 female students(49.8%) from 400 middle schools and 400 high schools. Results: Multiple logistic regression analysis after adjustment to demographic characteristics and oral health behavior showed experience with drinking and smoking in adolescents increased oral symptoms experienced by both male and female students (OR = 1.3, 95% CI = 1.20-1.34 / OR =1.3, 95% CI = 1.18-1.33), (OR = 1.3, 95% CI = 1.24-1.40 / OR = 1.4, 95% CI = 1.43-1.30). But the difference was not significant between genders. In terms of diet, consumption of carbonated beverages, snacks and fast food saw an increase in oral symptoms experience both gender compared with those whose “No(weekly)” in particular to women, alternatively vegetable, fruit consumption(weekly) were having less intake adolescents increase oral symptoms experience than “time daily(weekly)” intake adolescents both boy and girl especially to girl. Conclusions: There was a correlation between oral symptom experiences and health behaviors. There was also slight differences between genders, with more effect shown on female students. Based on this study, proper and systematic education of oral health management should be carried out at schools.