• Journal of Periodontal and Implant Science
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• v.40 no.2
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• pp.56-60
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• 2010

Purpose: The sinus lift procedure requires detailed knowledge of maxillary sinus anatomy and the possible anatomical variations. This study evaluated the location and prevalence of maxillary sinus septa using computed tomography (CT). Methods: This study was based on the analysis of CT images for posterior maxilla which were obtained from patients who visited Chonbuk National University Dental Hospital during the period of June 2007 to December 2008. With the exclusion of cases presenting any pathological changes, 236 maxillary sinuses in 204 patients were retrospectively analyzed. The average age of the patients was 50.9. The cases were divided into two groups, an atrophy/edentulous segment and a non-atrophy/dentate segment, and maxillary sinus septa of less than 2.5 mm were not taken in-to consideration. The location of septa was also divided for analysis into 3 regions: the anterior (1st and 2nd premolar), middle (1st and 2nd molar) and posterior (behind 2ndmolar) regions. Results: In 54 (20.9%) of the 204 patients there were pathologic findings, and those patients were excluded from the analysis. Sinus septa were present in 58 (24.6%) of the 236 maxillary sinuses and in 55 (27%) of the 204 total patients. In the atrophy/ edentulous ridge group (148 maxillary sinuses), 41 cases (27.7%) were found, and 17 cases (19.3%) were found in the non-atrophy/ dentulous ridge group (88 maxillary sinuses). In terms of location, septa were found in 18 cases (27.3%) in the anterior, in 33 cases (50%) in the middle and in 15 cases (22.7%) in the posterior regions. Conclusions: In the posterior maxilla, regardless of type of ridge (atrophy/edentulous or non-atrophy/dentate), the anatomical variation of sinus septa is diverse in its prevalence and location. Thus, accurate information on the maxillary sinus of thepatient is essential and should be clearly understood by the surgeon to prevent possible complications during sinus lifting.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.16 no.1
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• pp.41-48
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• 1986

It is known that radiation therapy is a kind of treatment choices of the maxillofacial tumors. This study is designed to investigate the irradiation effects on rat's periodontal tissues as functional tissues which relate to tooth-support, hard tissue formation and destruction. 20 rats (Sprague-Dowley branch, male) were devided into control group of 4 and experimental groupe of 16. Experimental group was singly exposed to Co-60 irradiation with 10 Gy in the head and neck region. Animals were sacrificed on 2 days, 1 week, 2 weeks and 3 weeks after the irradiation. The specimens were observed by histopathological examination employing H-E stain, van-Gieson stain and PA-ACH fluorescent stain. The results were as follows: 1. Cementoblasts and osteoblasts were gradually lost and rearranged along the external surfaces of the cementum and alveolar bone, but osteoclasts were almost not affected. 2. The cell numbers of the periodontal ligament were decreased due to the cellular atrophy and degeneration, but recovered almost normally on the 3rd week after irradiation. 3. The collagen fibers within the periodontal ligament were irregularly oriented, became finer and decreased in number. 4. The vessels of the periodontal ligament were decreased at the initial stage but increased again on the 2nd week after irradiation, and the hemorrhagic appearances, occurred within the tissues, due to the arterial destruction, were lasted until 3 weeks after irradiation. 5. The glycogen within the periodontal ligament was gradually increased and stored in the matrices of the cemental side on the 1st week after irradiation, but recovered almost normally on the 3rd week after irradiation.

• 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.37 no.2
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• pp.277-286
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• 2007

The edentulous posterior maxilla generally provides a limited amount of bone height because of atrophy of the ridge and pneumatization of the maxillary sinus, Maxillary sinus augmentation is one of the surgical techniques for reconstruction of the severely resorbed posterior maxilla. The purpose of this study was to evaluate the survival rate of implants and the long-term changes of graft height after maxillary sinus augmentation by lateral window approach. From September 1996 to July 2004, maxillary sinus augmentation with mixed grafts of autograft, allograft, xenograft and alloplast were performed on 45 patients and 100 implants were placed. We evaluated the survival rate of implants and the changes of BL(bone length)/IL(implant length) according to time using panoramic radiographs. The survival rate of implants was 91.0% for follow-up period. The mean reduction of graft heights was 0.34mm(3.0%) for 6 months and 1.22mm(1O.66%) for 3 years after augmentation. The total mean BL/IL was $1.34{\pm}0.21$ during 5 year observation period after augmentation and decreased slightly over time. The result means that graft materials were stable above the implant apex. BL/ILs of 1stage procedure were significantly decreased at 1-2 year, 3-4 year after augmentation and no statistically significant changes were observed in those of 2 stage procedure. The graft materials of both procedures were stable above the implant apex. No statistically significant changes of BL/IL were observed in the grafts combined with low amount of autogenous bone or without autogenous bone. The graft materials of both groups were stable above the implant apex. The results indicated that the placement of dental implants with maxillary sinus augmentation showed predictable clinical results and the grafts combined with low amount of autogenous bone or without autogenous bone had long-term resistance to resorption in maxillary sinus.

• Imaging Science in Dentistry
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• v.30 no.3
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• pp.159-168
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• 2000

Purpose: To elucidate the effects of the irradiation and calcium-deficient diet on expression of interleukin (IL)-1 during tooth formation of rat molar. Materials and Methods: The pregnant three-week-old Spague-Dawley rats were used for the study. The control group was non-irradiation/normal diet group, and the experimental groups were irradiation/normal diet group and irradiation/calcium-deficient diet group. The abdomen of the rats on the 9th day of pregnancy were irradiated with single dose of 350 cGy, The rat pups were sacrificed on the 14th day after delivery and the maxillae tooth germs were taken. The specimen were prepared to make sections for light microscopy, and some of tissue sections were stained immunohistochemically with anti-IL-l antibody. Results: In the irradiation/normal diet group, dental follicle showed fewer blood vessels, mononuclear cells, and fusions of mononuclear cells than in non-irradiation/normal diet group. Alveolar bone showed a few osteoblasts and osteoclasts. Periodontal ligament showed collagen fibers and fibroblasts with irregularity. Weak immunoreactivity for IL-l was shown in dental follicle, alveolar bone, and periodontal ligament. In the irradiation/calcium-deficient diet group, dental follicle showed sparse cellularity. Alveolar bone showed diminished number of osteoblasts. Periodontal ligament showed irregular collagen fibers and atrophy of cementoblasts and fibroblasts. No immunoreactivity for IL-1 was shown in dental follicle, alveolar bone, and periodontal ligament. Conclusion: Irradiation and calcium-deficient diet seems to cause disturbance of the expression of interleukin-l during tooth formation of rat molar.

• Journal of Korean Dental Science
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• v.17 no.2
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• pp.64-74
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• 2024

This case report presents the long-term radiographic outcomes of a novel approach for simultaneous lateral augmentation and implant surgery. A 60-year-old male patient who required tooth extraction of the maxillary central and lateral incisors due to trauma visited the clinic. After tooth extraction, severe horizontal and vertical deficiencies occurred owing to atrophy of the alveolar ridge, and a simultaneous guided bone regeneration (GBR) procedure was planned along with the installation of two implants. In the present case, a modification of the conventional 'sandwich technique' was used by placing the mixture of autogenous bone chips and xenografts at the outermost layer to maximize the osteogenic potential at the coronal part of augmentation while applying solely xenografts at the inner layer. To enhance volumetric stability, an autogenous block of periosteum harvested from the maxillary tuberosity was incorporated between the two layers. Cone-beam computed tomography was performed at baseline and 3 years after the surgery to compare radiographic outcomes. Dehiscence after fixture installation was successfully observed at the re-entry of the surgery site. Three years after the surgery, average horizontal bone gains of 6.11 mm and 4.12 mm were observed in the maxillary central and lateral incisor areas, respectively. Healthy peri-implant mucosa and well maintained marginal bone levels were observed 8 years after the surgery, meeting the criteria for implant success. The findings of this case suggest that a substantial amount of horizontal bone gain can be obtained with a layered approach using autogenous bone materials and xenografts, highlighting the advantages of incorporating autogenous blocks into the simultaneous GBR procedure.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.28 no.1
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• pp.171-191
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• 1998

The present study was designed to elucidate the effects of the Co-60 γ irradiation and/or calcium-deficient diet on the periodontal tissue formation in rat pups. The pregnant three-week old Sprague-Dawley rats were used for the study. The experimental group was divided into two groups, irradiation/normal diet group (Group 2) and irradiation/calcium-deficient diet group (Group 3). The control group was non-irradiation/normal diet group (Group 1). The abdomen of the rats at the 19th day of pregnancy were irradiated with single absorbed dose of 350 cGy. The rat pups were sacrificed on the 14th day after delivery, and the maxillae including molar tooth germ were taken. The specimens including the 1st molar tooth germ were prepared to make tissue sections for light and transmission electron microscopy. Some of tissue sections for light microscopy were stained immunohistochemically with anti-fibronectin and anti-osteonectin antibodies. The results were as follows; 1. In the periodontal ligament forming area, the fibroblasts of Group Z showed irregular arrangement and low activity. The immunoreactivity between the fibroblasts and collagen fibers was decreased, compared with Group 1. The fibroblasts of Group 3 showed atrophic change and clumped nucleus. The collagen fibers showed cystic change and low immunoreactivity to the fibronectin. 2. In the cementum forming area, the cementoblasts of Group 2 showed decrease of number and atrophic change. The cementoblasts of Group 3 showed edematous change, atrophy of cytoplasm, and clumping of nucleus. 3. In the alveolar bone forming area, the bone of Group 2 was thin and various degree of immunoreactivity to the osteonectin. Group 3 showed edematous osteoblasts, fibrous degeneration of bone marrow, and weak immunoreactivity to the osteonectin.

• Journal of Dental Rehabilitation and Applied Science
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• v.38 no.1
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• pp.60-68
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• 2022

A patient with severe periodontitis has causative factors that cause pathological tooth movement, the occlusion is disintegrated, and the vicious cycle of worsening periodontitis is repeated. In particular, when pathological tooth movement occurs in the maxillary anterior region, the patient has an aesthetic sense of atrophy, and the quality of life was reduced. Therefore, when orthodontic treatment was added to patients with severe periodontitis, it promotes the formation of new bone, reduces periodontal cysts, and obtains clinical attachment, which leads to favorable results in prosthetic restoration, thereby enabling ideal occlusion, function and aesthetics. Periodontal treatment, orthodontic treatment, natural tooth restoration, and implant prosthesis were planned for patients with pathological tooth movement in the anterior region due to loss of occlusal support in the posterior region. As a result, an ideal restoration space was secured, a stable restoration of occlusal contact was formed, and the maxillary anterior teeth were aesthetically improved.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.17 no.3
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• pp.214-219
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• 1995

Free grafting of oral mucosa for minor oral reconstruction was first described by Propper in ridge extension surgery. Situation calling for mucosal grafting procedures may relate to periodontal surgery, minor and major preprosthetic surgery, implant surgery, reconstruction in deformity cases after trauma, congenital cleft, gross atrophy and ablative tumor surgery. In the cases of 9 patients with mucosal defect of intraoral or orbital cavity after wide excision of tumor, preprosthetic surgery, and orbitoplasty, full-thickness mucosal graft were used to close a large defect. Four patients received buccal mucosal graft for preprosthetic surgery or orbitoplasty, one patient had benign tumor and the others had malignant tumors located on the palate or upper alveolus. Buccal mucosal graft donor site morbidity and trismus were minimal and healing of surgical defect was satisfactory. So we present the case with review of literatures.

• Journal of Periodontal and Implant Science
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• v.50 no.4
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• pp.238-250
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• 2020

Purpose: This study aimed to evaluate the biocompatibility and the mechanical properties of ultraviolet (UV) cross-linked and biphasic calcium phosphate (BCP)-added collagen membranes and to compare the clinical results of ridge preservation to those obtained using chemically cross-linked collagen membranes. Methods: The study comprised an in vitro test and a clinical trial for membrane evaluation. BCP-added collagen membranes with UV cross-linking were prepared. In the in vitro test, scanning electron microscopy, a collagenase assay, and a tensile strength test were performed. The clinical trial involved 14 patients undergoing a ridge preservation procedure. All participants were randomly divided into the test group, which received UV cross-linked membranes (n=7), and the control group, which received chemically cross-linked membranes (n=7). BCP bone substitutes were used for both the test group and the control group. Cone-beam computed tomography (CBCT) scans were performed and alginate impressions were taken 1 week and 3 months after surgery. The casts were scanned via an optical scanner to measure the volumetric changes. The results were analyzed using the nonparametric Mann-Whitney U test. Results: The fastest degradation rate was found in the collagen membranes without the addition of BCP. The highest enzyme resistance and the highest tensile strength were found when the collagen-to-BCP ratio was 1:1. There was no significant difference in dimensional changes in the 3-dimensional modeling or CBCT scans between the test and control groups in the clinical trial (P>0.05). Conclusions: The addition of BCP and UV cross-linking improved the biocompatibility and the mechanical strength of the membranes. Within the limits of the clinical trial, the sites grafted using BCP in combination with UV cross-linked and BCP-added collagen membranes (test group) did not show any statistically significant difference in terms of dimensional change compared with the control group.