• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.1
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• pp.157-161
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• 1999

Odontomas, hamartomas of odontogenic origin, are composed of all the structures that make up teeth. The WHO distinguishes odontoma into two types. The complex odontoma is defined as "a malformation in which all the dental tissues are represented, individual tissues being mainly well-formed but occurring in a more or less disorderly pattern." The compound odontoma is defined as "a malformation in which all the dental tissues are represented in a more orderly pattern than in the complex odontoma, so that the lesion consists of many toothlike structures. Most of these structures do not resemble morphologically the teeth of normal dentition, but in each one enamel, dentine, cementum, and pulp are arranged as in the normal tooth." Almost all odontomas are located intraosseously, but they have occasionally been reported in extrabony location. Peripheral or soft tissue odontomas, those arising outside of the alveolar bone, are very rare. Peripheral or soft tissue odontoma are defined as tumors that demonstrate the histologic characteristics of their intraosseous counterparts but occur solely in the soft tissue covering the tooth-bearing portion of the mandible and maxilla. When they mature, they appear as a radiopaque mass without the peripheral halo. The final diagnosis should be confirmed by biopsy. The origin of peripheral odontoma is probably related to remnants of the dental lamina in the gingiva. The treatment of choice is complete surgical excision, similarly to intraosseous odontoma and it does not tend to recur. This report presents a case of 5-year-old boy with swelling on labial gingiva of primary central incisor. And it was diagnosed as peripheral odontoma by excisional biopsy.

• Journal of Periodontal and Implant Science
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• v.29 no.3
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• pp.645-654
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• 1999

Interleukin-6(IL-6) stimulate osteoclast differentiation. $17{\beta}$-estradiol, 1,25-dihydroxyvitamin $D_3$(1,25-$(OH)_2D_3$) and interleukin-$1{\beta}$ inhibit or stimulate osteoclast differentiation by decreasing or increasing the synthesis of interleukin-6(IL-6) from stromal/osteoblastic cells, respectively. Periodontal ligament(PDL) cells reside between the alveolar bone and the cementum and have osteoblastic characteristics. To estimate the effect of $17{\beta}$-estradiol and 1,25$(OH)_2D_3$ on IL-6 production of PDL cells, PDL cells were treated with $17{\beta}$-estradiol or 1,25-$(OH)_2D_3$ in the absence or the presence of IL-$1{\beta}$. The concentration of IL-6 produced form PDL cells was determined by enzym linked immunosorbent assay(ELISA). In unstimulated PDL cells, we detected constitutive production of IL-6 at 1st and 2nd day. IL-$1{\beta}$ increased IL-6 synthesis at 1st day and 2nd day. $17{\beta}$-estradiol had no significant effect on the secretion of this cytokine, either constitutively or after stimulation with IL- $1{\beta}$(0.05 ng/ml). 1,25-$(OH)_2D_3$($10^{-8}M$) decreased not only constitutive IL-6 production but also IL-$1{\beta}$-induced IL-6 production at 2nd day. These results suggest that 1,25-$(OH)_2D_3$ may control IL-$1{\beta}$-induced osteoclast differentiation by decreasing IL-$1{\beta}$-induced IL-6 secretion of PDL cells.

• Journal of Periodontal and Implant Science
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• v.37 no.3
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• pp.637-646
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• 2007

Implants placed immediately after tooth extraction have been shown to be a successfully predictable treatment modality. Several clinical papers suggest that placing implants immediately after tooth extraction may provide some advantages: reduction of the number of surgical procedures or patient visits, preservation of the dimensions of alveolar ridge, and shortening of the interval between the removal of the tooth and the insertion of the implant supported restoration. In this case report, three patients received single immediate implant placements to replace a maxillary anterior tooth at the time of extraction. As the three cases were somewhat different, treatment protocols had to be modified as follows: Case 1. Immediate implant placement with healing abutment connection. Case 2. Immediate implant placement with immediate provisionalization. Case 3. Immediate implant placement with Guided Bone Regeneration(GBR). Every implant of these cases was placed in proper position buccolingually, mesiodistally and apicocoronally, The procedures following implantation such as immediate provisionalization and GBR were free of problem. Healing of each case was uneventful. In all cases, treatment outcomes were mostly satisfactory and the results maintained during follow-up periods. However, one case (Case 3) showed some papilla loss due to failure in delicate soft tissue handling during surgery. This papilla loss was compromised by prosthetic means. In conclusion, immediate implant placement in the fresh extraction socket can be a valid and successful option of treatment in aesthetic area. Moreover, this treatment protocol seems to maintain the preexisting architecture of soft and hard tissues in most cases.

• Journal of Periodontal and Implant Science
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• v.37 no.3
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• pp.553-562
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• 2007

Osteoblasts regulate osteoclastogenesis by production of various cytokines. Aggregatibacter(A) ac-tinomycetemcomitans is one of periodontopathogens which invades gingival tissue. Therefore, clarifying the effect of alive A. actinomycetemcomitans on osteoblasts is important to understand the mechanism of alveolar bone resorption in periodontitis. We investigated induction of osteoclastogenesis-inducing cytokines, adherence, and invasion by A. actinomycetemcomitans in osteoblasts. Osteoblasts were isolated from mouse calvaria and expression of cytokines was determined by RT-PCR. When the ratio of the number of A. actinomycetemcomtians to the number of osteoblasts was 10:1, 50:1 and 100:1, RANKL mRNA expression was increased. A. actinomycetemcomitans also increased expression of macrophage inflammatory protein (MIP) -1${\alpha}$, interleukin (IL)-1${\beta}$, and tumor necrosis factor (TNF)-${\alpha}$. A. actinomycetemcomitans attached to and invaded osteoblasts at ratio of 1000:1. These results suggest that A. actinomycetemcomitans increases osteoclastogenesis-inducing ability of osteoblasts by stimulating the expression of RANKL, MIP-1${\alpha}$,IL-1${\beta}$, and TNF-${\alpha}$ and that invasion of A. actinomycetemcomitans provides a means by which the bacteria escape from immune system and antibiotic therapy.

• Journal of Korean Dental Science
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• v.2 no.1
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• pp.31-38
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• 2009

With today's social and cultural personal interactions, greater leisure time and participation in sports activities, and growing traffic volume, the risk of physical trauma has increased markedly. This is a clinical and retrospective study of patients exposed to oral and maxillofacial trauma. We clinically observed 72 patients with trauma in the Department of Oral and Maxillofacial Surgery, Kyunghee University Dental Hospital, from June 2006 through November 2007. The following data was obtained: 1. The male:female ratio of patients having experienced physical trauma was 6.2:1, with most patients in their twenties. 2. Traffic accident (37.5%) was the most common cause of trauma. 3. The highest incidence of fracture occurred to the zygomatic arch(22.1%) among mid-facial fractures and angle(37.5%), symphysis(35.4%) in mandible fractures. 4. Open reduction (88.9%) was the most frequently used form of treatment. Closed reduction was performed on the remaining 11.1% of cases. 5. Teeth and alveolar bone damage occurred in 23.6% of all cases. 6. Other injuries that were related to mid-face fracture occurred in 27.8% of all cases. 7. Post-operative complications occurred in 31.9% of cases, and the highest complication was the nerve injury.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.34 no.3
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• pp.220-225
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• 2012

Wegener's granulomatosis (WG) is an autoimmune disease of unknown etiology characterized by the triad of necrotizing granulomatous lesion in the upper and lower respiratory tracts or both, disseminated vasculitis involving both small arteries and veins, and necrotizing glomerulonephritis. The most common oral lesions associated with WG are ulceration and strawberry gingivitis. A 47-years old man in medical care associated WG was consulted our Division of Oral and Maxillofacial Surgery for the chief complaint of toothaches. Pre-operative panorama showed the alveolar radiolucency and the loss of lamina dura regarding the left upper teeth. An oropharyngeal magnetic resonance imaging also revealed the increased bone marrow signal intensity on the left maxilla. Under the impression of maxillary osteonecrosis due to WG, maxillary saucerization with removal of involved teeth was performed. We obtained good results and report the first case of WG in Korea, with the review of literatures regarding oral and general systemic features.

• The korean journal of orthodontics
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• v.19 no.1 s.27
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• pp.45-59
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• 1989

This study was undertaken to analyze the displacement and stress distribution in the mandible according to the pulling directions during mandibular first molar cervical traction after mandibular second molar extraction. The 3-dimensional finite element method(FEM) was used for a mathematical model composed of 594 elements and 1019 nodes. An orthodontic force, 450 gm, was applied to the each mandibular first molar in parallel, and below the occlusal plane by $7^{\circ}\;and\;25^{\circ}$ and meet the midsagittal plane by $40^{\circ}$ toward posterior direction. The results were as follows: 1. Mandibular teeth were displaced in more downward, posterior and lateral direction. Especially high stress was noted in case of parallel pull than in case of below the occlusal plane by $7^{\circ}\;and\;25^{\circ}$. 2. Mandibular first molar was moved bodily. 3. Generally, alveolar bone, mandibular body, ascending ramus and mandibular angle portion were displaced in downward, posterior and lateral direction. But coronoid process was displaced in downward, forward and lateral direction, and anterior and inner middle portion of condyle head and neck were displaced in downward, forward and medial direction, and posterior and outer middle portion of condyle head and neck were displaced in upward, forward and medial direction. 4. Maximum stress was observed at the condyle head and neck portion. With steeper direction of force, condyle head and neck showed more stress than parallel relation to the occlusal plane.

• The Journal of the Korean dental association
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• v.53 no.2
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• pp.82-95
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• 2015

Background: Interest in medical malpractice claims and accidents is a day-to-day social issue to general public as well as medical personnel. Related laws and regulations already have been established, and institutions based on the laws and regulations also have been founded. However, in our dental community, interest and response to the issue seem insufficient. Methods: We searched four medical literature databases that are mainly cited in the medical community. Keywords including 'dental malpractice claims', 'patient safety' and 'medical accident' were used for the search. Among the selected literatures, we chose specific ones separately whose content is authentic and easily approachable. Results: Medical malpractice claims and accidents tend to increase around the world. As the cost or the difficulty level of surgery increases, the dispute rate also increases, which appears even more apparent in developed countries. Preventive measures to prevent the disputes and accidents are not significantly different. Three critical of them include relationship of doctor with patient, the informed consent and medical record. Conclusion: Tools for accident occurrence or communication improvement have been introduced. All of those cost time and money. However, education or professional request of liability insurance companies, self-education and provision of guidelines can be immediately implemented. To implement those, dentists' promotion at the regional or national level is imperative. rhBMP-2 is widely used at sinus augmentation, alveolar bone defect, and socket preservation.

• The Journal of the Korean dental association
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• v.55 no.4
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• pp.276-283
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• 2017

Maxillary sinus squamous cell carcinoma is a relatively rare disease, comprising only 3% of malignant diseases of head and neck. As the growth rate is high and its prognosis is poor compared to others, the 5-year survival rate of maxillary sinus squamous cell carcinoma(MSSCC) is 23.4-49%. We introduce two rare clinical cases of squamous cell carcinoma originated from maxillary sinus of which symptoms include toothache and gingival swelling. On clinical examinations of both patients, deep periodontal pockets on upper right posterior teeth were detected. On panoramic images, the bony destruction of the maxillary sinus and its surrounding structures were not obvious and only alveolar bone loss was noted. It is difficult to diagnose MSSCC at an early stage due to symptoms of tooth pain and gingival swelling that are similar to that of periodontal diseases. However, if the symptoms do not improve after routine treatment of upper teeth, dentists should bear in mind of underlying malignant mass as differential diagnosis, thus early detection of the lethal disease. The aim of this study is to caution dental practitioners that malignancies have a potential to mimic periodontal diseases by introducing two cases of maxillary sinus squamous cell carcinoma presented as periodontitis.

• The korean journal of orthodontics
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• v.47 no.1
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• pp.21-30
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• 2017

Objective: The aim of this study was to investigate the three-dimensional (3D) position of the center of resistance of 4 mandibular anterior teeth, 6 mandibular anterior teeth, and the complete mandibular dentition by using 3D finite-element analysis. Methods: Finite-element models included the complete mandibular dentition, periodontal ligament, and alveolar bone. The crowns of teeth in each group were fixed with buccal and lingual arch wires and lingual splint wires to minimize individual tooth movement and to evenly disperse the forces onto the teeth. Each group of teeth was subdivided into 0.5-mm intervals horizontally and vertically, and a force of 200 g was applied on each group. The center of resistance was defined as the point where the applied force induced parallel movement. Results: The center of resistance of the 4 mandibular anterior teeth group was 13.0 mm apical and 6.0 mm posterior, that of the 6 mandibular anterior teeth group was 13.5 mm apical and 8.5 mm posterior, and that of the complete mandibular dentition group was 13.5 mm apical and 25.0 mm posterior to the incisal edge of the mandibular central incisors. Conclusions: Finite-element analysis was useful in determining the 3D position of the center of resistance of the 4 mandibular anterior teeth group, 6 mandibular anterior teeth group, and complete mandibular dentition group.