• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.1
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• pp.23-26
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• 2010

The vascular changes in periodontal tissues cause local hypoxia which seems to affect the periodontal tissue cells. Abrupt changes in oxygen availability within the periodontium have been suggested to have a regulatory role in alveolar bone remodeling during tooth movement, bone growth or fracture healing. The purpose of this study was to study the effects of hypoxia on formation of osteoclast responsible for bone resorption, in vitro. Primary mouse bone marrow cells were cultured in normoxic (20% $O_2$) and hypoxic (1% $O_2$) conditions and assayed for cellular proliferation. The results obtained were as follows : 1. Reducing oxygen tension increased the formation of multinucleated osteoclasts. 2. Hypoxic stimulus increased the size of mature osteoclasts.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.37
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• pp.42.1-42.5
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• 2015

In the field of oral-maxillofacial surgery, vascular malformations present in various forms. Abnormalities in the size of the tongue by vascular malformations can cause mandibular prognathism and skeletal deformity. The risk in surgical treatment for patients with vascular malformation is high, due to bleeding from vascular lesions. We report a rare case of macroglossia that was treated by partial glossectomy, resulting in an improvement in the swallowing and mastication functions in the patient. A 25-year-old male patient with severe open-bite and mandibular prognathism presented to our department for the management of macroglossia. The patient had a difficulty in food intake because of the large tongue. Orthognathic surgery was not indicated because the patient had severe jaw bone destruction and alveolar bone resorption. Therefore, the patient underwent partial glossectomy under general anesthesia. There was severe hemorrhaging during the surgery, but the bleeding was controlled by local procedures.

• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.4
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• pp.397-406
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• 2012

Loss of tooth results in remodeling and resorption of surrounding alveolar bone which causes atrophic edentulous ridge and gradually decreasing gingival attachment. As a result, edentulous patients face difficulty in using dentures due to pain, decrease of support, decline of masticatory efficiency of complete denture. To improve this, overdenture with implant in the mandible and attachment are considered as a treatment of choice as a favorable treatment. In this case, a patient with edentulous ridge for long period is rehabilitated by complete denture in maxilla and implant overdenture using Locator$^{(R)}$ attachment in mandible.

• Journal of Dental Rehabilitation and Applied Science
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• v.24 no.4
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• pp.351-359
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• 2008

It is difficult to provide prosthodontic treatment to fully edentulous patients with severe alveolar bone resorption, because this makes patents hard to endure functional load, and to adapt to the dentures, which result in emotional stress to patients. Implant supported overdenture can be chosen to solve these problems. Among several types of them, the implant retained and tissue supported overdenture, is available to the patients of low masticatory force with the reduced cost. Attachments also can be used for increasing retention and esthetics in dentures. Especially, $Locator^{(R)}$ system needs a small vertical interarch space for restoration and is able to compensate the difference of angle between fixtures. In this study, we restored maxilla with conventional complete denture, and mandible with implant and tissue supported overdenture and $Locator^{(R)}$ system.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.27 no.1
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• pp.24-40
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• 2018

Often there are edentulous patients with severe vertical resorption of the alveolar ridge so that implant placement in the mandibular posterior is impossible. In this case, implants can be placed in the anterior portion of the mandible and the patient can be treated with an implant assisted overdenture, but the inherent discomfort of the removable prosthesis can not be overcome. However, if implants are appropriately placed between the mental foramen of both sides and a fixed hybrid prosthesis is fabricated to the patient, the patient will be satisfied without the inconvenience of the removable prosthesis. However, the treatment plan should be well designed to prevent disadvantages and expected complications of fixed hybrid prosthesis. Based on my clinical experience, I will explain treatment plan and protocol in detail.

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.1
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• pp.36-42
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• 2021

Even though implant overdentures are preferentially recommended to mandibular edentulous patients, many patients may select conventional complete dentures due to cost and general condition. Proper retention and stability of conventional complete dentures in patients with severe alveolar bone resorption is difficult to achieve. To overcome the limitations, mandibular suction dentures with the closed mouth impression technique have been used. However, the previous technique requires the Frame cut back tray, the Centric tray, and the Gnathometer M. This article introduces a technique for fabricating a mandibular suction denture with common dental materials.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.47 no.3
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• pp.153-174
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• 2021

Dental implants are popular for dental rehabilitation after tooth loss. The goal of this systematic review was to assess bone changes around bone-level and tissue-level implants and the possible causes. Electronic searches of PubMed, Google Scholar, Scopus, and Web of Science, and a hand search limited to English language clinical trials were performed according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines up to September 2020. Studies that stated the type of implants used, and that reported bone-level changes after insertion met the inclusion criteria. The risk of bias was also evaluated. A total of 38 studies were included. Eighteen studies only used bone-level implants, 10 utilized tissue-level designs and 10 observed bone-level changes in both types of implants. Based on bias assessments, evaluating the risk of bias was not applicable in most studies. There are vast differences in methodologies, follow-ups, and multifactorial characteristics of bone loss around implants, which makes direct comparison impossible. Therefore, further well-structured studies are needed.

• The korean journal of orthodontics
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• v.18 no.2
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• pp.311-327
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• 1988

Vascular changes in the periodontal ligament of the rat incisors following application of experimental orthodontic forces were examined by the India ink perfusion method. 57 rats were used for this experiment. The rats were divided into experimental group (54 rats) and control group (3 rats). 54 experimental rats were divided into group I (27 rats) and group II (27 rats). The right and left upper incisors of group. I and group II rats were separated distally with forces of 20gm, 70gm respectively. The vascular changes of periodontal ligament were observed histologically by means of light microscope after 1, 2 and 3 days of tooth movement and 1,3,5,8,14, and 21 days after removal of orthodontic force. The results were as follows; 1. After one day of tooth movement, occlusion of blood vessels, hyalinization of periodontal ligament and resorption of alveolar bone adjacent to the alveolar crest on pressure side were observed. Above the tissue changes on the pressure side of group II were more severe than those of group I. Especially, septal bone of group II was separated after 2 days of tooth movement. 2. In tension zones, periodontal space was widened and periodontal fibers were orientated in the direction of puil. The blood vessels of periodontal ligament were distended. New bone deposition was seen along the inner surface of the alveolus after 2 days of tooth movement. 3. After 3 days of tooth movement, deposition of new bone was seen along the periosteal surface of alveolar bone on pressure side, progressing with increasing after removal of orthodontic force. Remodelling of the new bone was occurred 5 days after removal of orthodontic force. 4. 3 days after removal of orthodontic force, invasion of blood vessels into the marginal periodontal ligament on pressure side was observed clearly and the vessels below the epithelial attachment were increased. 5. After removal of orthodontic force, hyalinized structures disappeared concomittantly with an invasion of blood vessels from the neighboring periodontal ligament. 14 days after removal of orthodontic force, the vessels in the periodontal ligament of group I were finished the vascular rearrangement. 21 days after removal of orthodontic force, the vessels in the periodontal ligament of group II were finished the vascular rearrangement.

• The Journal of the Korean dental association
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• v.47 no.10
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• pp.669-676
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• 2009

Purpose : Anterior region is crucial area for esthetic implant restoration. However, the alveolar process undergoes atrophy after removal of teeth and creates unfavorable situation for implant installation. The knowledge of the thickness of alveolar bone is required to estimate and expect the bone resorption after extraction. The aim of this study is to measure facial, palatal and faciopalatal bone thickness on maxillary anterior teeth. Methods : Facial, palatal, and faciopalatal bone thickness were measured on the computed tomography (CT) images from 57 patients, using an image analyzer program (Ondemand$3D^{(R)}$, Cybermed, Seoul, Korea). Results : The thickness of facial bone in incisors, lateral incisors and canines were less than 1 mm. The thickness of facial bone increased from anterior to posterior region and the thickness of palatal bone increased from posterior to anterior region. Conclusion : The measurement can be used for planning implant surgery before extraction. CT has are clinically useful in the evaluation of thickness of alveolar bone.

• Journal of Periodontal and Implant Science
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• v.23 no.1
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• pp.109-126
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• 1993

Refractory periodontitis manifest progressive attachment loss in a rapid and unrelenting manner regardless of the type or frequency of therapy applied. The purpose of this study was ta evaluate the relation between the level of cytokines in GCF and periodontopathic microflora with disease activity of refractory periodontitis. Selection of patients with refractory periodontitis (7 males, 3 females) were made by long term clinical observation including conventional clinical history and parameters. Teeth that showed pocket depth greater than 6mm were selected as sample teeth. Subjects were examined at baseline and after 3 months. Prior to baseline test, individual acrylic stent was fabricated. Reference grooves were made on each sample tooth site. Pocket depth and attachment loss were measured by Florida Probe. Gingival index was measured at 4 sites each sample teeth. Disease activity was defined as attachment loss of ${\ge}$ 2.1mm, as determined by sequential probing and tolerance method. The pattern and amount of alveolar bone resorption was observed with quantitative digital subtraction image processing radiography. Morphological analysis of subgingival bacteria was taken by phase contrast microscopy. Predominant cultivable bacterial distribution and frequency were compared between disease-active and disease-inactive site using immunofluorescence microscopy and selective microbial culturing. Levels of $interleukin-l{\beta}$, 2, 4, 6 and $TNF-{\alpha}$ in GCF and blood serum sample were quantified by ELISA. In active sites, P. intermedia was significantly increased to compare with inactive site. $IL-1{\beta}$, IL-2, IL-6 and $TNF-{\alpha}$ in GCF were increased in active sites and IL-2 in serum was increased in active patients significantly. Alveolar bone loss in active site was correlated with $IL-1{\beta}$, IL-2 in GCF. And loss of attachment in active site was correlated with IL-2 in GCF. These results demonstrate that IL-2 in serum, $IL-1{\beta}$, IL-2, IL-6 and $TNF-{\alpha}$ in GCF, P, intermedia might be used as possible predictors of disease activity in refractory periodontitis before it is clinically expressed as attachment loss and quantitative alveolar bone change.