• Journal of Periodontal and Implant Science
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• v.31 no.2
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• pp.437-449
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• 2001

The socket preservation procedure was a simple and effective technique, and has better prognosis for implantation. The socket preservation usually used barrier membrane in combination with/without alloplastic bone materials. A recently study had shown that a regenerative therapy to tooth extraction utilizing growth factors made better results. Platelet-rich plasma was clinically easy method that acquired the growth factors, and is known that accelerated new bone formation and mineralization of bone graft materials. The purpose of this study was to evaluate clinical and histopathologic results which occur following socket preservations using platelet-rich plasma and bovine bone powder. Twelve patients who required extraction of one or more teeth for implantation at the department of periodontics in Dankook University Dental Hospital were selected. Extraction sockets were treated by using platelet-rich plasma and bovine bone powder. 3 months later, we observed clinical and histopathological results as follows: 1. Internal vertical measurement was an average of 7.33mm preoperatively and statistically significantly decreased to an average of 1.42mm postoperatively(p<0.05). 2. External vertical measurement was an average of 3.33mm preoperatively and decreased to an average of 2.75mm postoperatively; therefore there was no significant difference. 3. Horizontal measurement was an average of 7.75mm preoperatively and statistically decreased to an average of 6.08mm postoperatively(p<0.05). 4. Osteocyte-like cells and new bone formation connected with bovine bone grafts were observed in histopathologic examination. This study implied that platelet-rich plasma and bovine bone powder grafts were effective treatment for socket preservation and regeneration of severe bony defect made by implantation failure.

• Journal of Dental Rehabilitation and Applied Science
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• v.36 no.3
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• pp.196-202
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• 2020

Recently three-dimensional (3D) printed complete dentures are becoming more widely recognized as one of the treatment options for the edentulous patients. Korean National Healthcare, however, has not yet approved the application of the 3D printed dentures, and in the cases where the dentures should be refabricated, the conventional fabrication process needs to be entirely repeated. However, during the conventional process, the digital scan data of some key steps could be easily obtained. In this clinical case, using these data, a new pair of 3D printed dentures that improved the limitations of the first conventional dentures were successfully fabricated.

• Radiation Oncology Journal
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• v.13 no.3
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• pp.225-231
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• 1995

Malignant fibrous histiocytoma(MFH) of the maxilla is a rare malignant bone tumor Seven percents of all MFH occur in the head and neck. Approximately $12{\%}$ of these tumors occur in the maxilla. Local recurrence or distant metastasis was reported in $55{\%}$ of cases of maxillary MFH. The mean survival time of 30 months was reported from a review of 14 MFHs in the maxilla, mandible and oral soft tissues. MFH of the maxilla is best treated surgically but radical neck dissection does not appear to be indicated unless there is clinical evidence of lymph node metastases Although the use of radiation therapy for head and neck MFH has not been studied for a series of cases, individual cases of regression or histological change have been reported. Other authors have reported numbers of cases who received radiation therapy without benefit. Response to combination chemotherapy has been reported in $33{\%}$ of 23 patients with recurrent or metastatic MFH. We report here a case of MFH occurring in the maxilla with a review of literature about the clinical behavior and treatment of these lesions.

• The korean journal of orthodontics
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• v.51 no.5
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• pp.346-354
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• 2021

Objective: To compare the effectiveness of ibuprofen, acetaminophen, and chewing gum for orthodontic pain relief and to assess if chewing gum can be a non-pharmacological alternative for orthodontic pain relief. Methods: The study enrolled 106 patients of both sexes, aged ≥ 12 years, with body weight > 50 kg, and mild-to-moderate dental crowding in the upper arch. After randomization and allocation concealment, the intervention groups were either administered with ibuprofen (400 mg) or acetaminophen (500 mg) or chewed sugar-free chewing gum immediately after initial archwire placement and every 6 hours for 1 week if the pain persisted. The control group did not receive any pain relief. The pain was assessed on a 100-mm visual analog scale at rest and while biting down at T1 (2 hours), T2 (24 hours), T3 (2 days), T4 (3 days), T5 (7 days), and T6 (21 days). Statistical analyses were performed using the Kruskal-Wallis and post-hoc Mann-Whitney U tests (α = 0.05). Results: The chewing gum group experienced more pain relief than the ibuprofen group at while biting down at T3 (p = 0.04) and at rest at T4 (p < 0.001). The chewing gum group reported more pain relief than the acetaminophen and control groups while biting down at T3 (p = 0.03 and p = 0.0006, respectively) and T4 (both p < 0.001). Conclusions: Chewing gum can be a non-pharmacological alternative for orthodontic pain relief at 2 and 3 days after initial archwire placement.

• Journal of Periodontal and Implant Science
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• v.50 no.6
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• pp.379-391
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• 2020

Purpose: The aims of this study were to evaluate the 5-year cumulative survival rate (CSR) of implants placed with guided bone regeneration (GBR) compared to implants placed in native bone, and to identify factors contributing to implant failure in regenerated bone. Methods: This retrospective cohort study included 240 patients who had implant placement either with a GBR procedure (regenerated bone group) or with pristine bone (native bone group). Data on demographic features (age, sex, smoking, and medical history), location of the implant, implant-specific features, and grafting procedures and materials were collected. The 5-year CSRs in both groups were estimated using Kaplan-Meier analysis. Risk factors for implant failure were analyzed with a Cox proportional hazards model. Results: In total, 264 implants in the native bone group and 133 implants in the regenerated bone group were analyzed. The 5-year CSRs were 96.4% in the regenerated bone group and 97.5% in the native bone group, which was not a significant difference. The multivariable analysis confirmed that bone status was not an independent risk factor for implant failure. However, smoking significantly increased the failure rate (hazard ratio, 10.7; P=0.002). Conclusions: The 5-year CSR of implants placed in regenerated bone using GBR was comparable to that of implants placed in native bone. Smoking significantly increased the risk of implant failure in both groups.

• The korean journal of orthodontics
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• v.51 no.3
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• pp.157-165
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• 2021

Objective: This study aimed to identify the clinical effectiveness of two different penetration depths of micro-osteoperforations (MOPs) on the rate of orthodontic tooth movement. Methods: Twenty-four patients requiring the removal of the upper first premolar teeth were selected and randomly divided into two groups. The control group participants did not undergo MOPs. Participants in the experimental group underwent three MOPs each at 4-mm (MOP-4) and 7-mm (MOP-7) depths, which were randomly and equally performed to either the left or right side distal to the canine. The retraction amount was measured on three-dimensional digital models on the 28th day of retraction. MOP-related pain was measured using a visual analog scale (VAS). Between-group statistical differences in the VAS scores were determined using an independent t-test and those in canine retraction were determined using analysis of variance and post-hoc Tukey test. Results: No significant difference was found between the MOP-4 (1.22 ± 0.29 mm/month) and MOP-7 (1.29 ± 0.31 mm/month) groups in terms of the canine retraction rate. Moreover, both the groups demonstrated a significantly higher canine movement than the control group (0.88 ± 0.19 mm/month). MOPs did not significantly affect the mesialization of the posterior teeth (p > 0.05). Moreover, the pain scores in the MOP-4 and MOP-7 groups were similar and showed no statistically significant difference. Conclusions: Three MOPs with a depth of 4 mm can be performed as an effective method to increase the rate of tooth movement. However, three MOPs with depths of 4-7 mm does not additionally enhance tooth movement.

• Journal of the korean academy of Pediatric Dentistry
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• v.48 no.2
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• pp.229-236
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• 2021

Eruption disturbances of the mandibular first molars can cause multiple problems in occlusal development although they are extremely rare. Early diagnosis and treatment are very important to prevent complications associated with eruption disturbances. The present case report describes the treatment of two cases of eruption disturbances of the mandibular first permanent molar. A fixed appliance composed of a cantilever spring with mandibular second deciduous molar as an anchor tooth was used to tract the impacted mandibular first permanent molar. The success of both cases shows that this novel traction appliance can be used to induce the eruption of an impacted mandibular first permanent molar within a short time in patients with intact mandibular second deciduous molar as an anchor tooth.

• Journal of Dental Rehabilitation and Applied Science
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• v.35 no.2
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• pp.64-71
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• 2019

Retromolar pad is one of anatomical landmarks to use clinically for determining of specific occlusal plane level in edentulous patients and is inherently a soft tissue mass; located at the distal end of mandible and should be covered with denture. The shapes of retromolar pad show variability because it might be inevitable to be resultant forms from healing and remodeling process after the extraction of last molars. Considerations would be focused on those resultant shapes and classification with anatomical relationships and clinical significances.

• Imaging Science in Dentistry
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• v.49 no.1
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• pp.9-17
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• 2019

Purpose: This study aimed to introduce a novel method to evaluate the alveolar bone and interdental septum in the anterior mandible using cone-beam computed tomography (CBCT). Materials and Methods: Fifty-six CBCT scans from adult patients were selected. The CBCT scans were obtained before and after orthodontic treatment. The following measurements were taken: width of the alveolar bone and the interdental septum, height of the interdental septum, height of the bone plates, distance between the cementoenamel junction and marginal bone crests, and vertical positioning of the mandibular incisor, using the lingual plane as a reference. To test the reproducibility and the stability of the lingual plane, a triangle was traced in the anterior mandible. The intra-class correlation coefficient(ICC) was used to determine intra- and inter-examiner agreement. The paired Student t-test was used to evaluate the area of the triangle and the reproducibility of all measurements. Results: The ICC was excellent for the alveolar bone and dental measurements (0.9989 and 0.9977, respectively), as well as for the interdental septum (0.9987 and 0.9961, respectively). The area of the triangles showed stability in the lingual plane (P>0.05). For the alveolar bone, mandibular incisor, and interdental septum measurements, no statistically significant differences were found between the 2 examiners(P>0.05), confirming the technical reliability of the measurements. Conclusion: The method used in this study provides a valid and reproducible assessment of alveolar bone dimensions in the anterior mandible measured on CBCT images.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.45 no.4
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• pp.199-206
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• 2019

Objectives: In mandibular edentulism, the treatment option with a two-interforaminal implant-retained bridge and a removable partial denture is rarely evaluated in literature. The aim of this in vitro study was to evaluate the stress distribution of this treatment option by comparing it with traditional treatment options with interforaminal implants in the edentulous mandible. Materials and Methods: Two interforaminal implants were placed in a formalin-fixed cadaver mandible, and overdentures with three different types of attachments were fabricated: (1) two ball attachments and an overdenture, (2) a Dolder bar and an overdenture, and (3) screw-retained two-implant inter-canine porcelain fused to a metal bridge and an implant-assisted removable denture (IARD) with precision attachments. Three biting conditions were generated for each denture type, and the strains were documented under vertical loading of 100 N. Results: The calculated strain values from measured strains in all measurement sites and loading conditions for the screw-retained two-implant intercanine porcelain fused to a metal bridge and a cast framework partial denture with precision attachments situation were lower than in the other scenarios (P<0.05). Conclusion: Within the limitations of the present study, it can be concluded that an IARD may be a reasonable and valuable alternative to ball attachments or a bar in two interforaminal implants, especially when the patients prefer to be able to show their teeth even when they take out their removable dentures.