• Journal of Periodontal and Implant Science
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• v.49 no.5
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• pp.299-309
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• 2019

Purpose: To analyze the ridge profile of the anterior maxilla using cone-beam computed tomography and to assess the clinical significance of the ridge profile by performing virtual implant placement. Methods: Thirty-two cone-beam computed tomography scans of anterior maxillae were included. For each tooth, a vertical line was made along the longitudinal axis, and 3 horizontal lines at 1-, 3-, and 5-mm levels below the labial bone crest were drawn perpendicularly to the vertical reference. At these levels, the thickness of the alveolar ridge (RT), and the labial (LT) and palatal bone plate (PT) were measured. Then, virtual implant placement using standard and tapered implants was performed. A generalized linear mixed model was used for statistical analysis. Results: The teeth were located labially based on the proportion of LT and PT with respect to RT. At the 1-mm level, the value of LT was between $1.0{\pm}0.4mm$ for central incisors and $1.3{\pm}0.6mm$ for canines. A large number of teeth had area(s) with less than 1-mm-thick labial bone between the 1- and 5-mm levels below the crest. The mean PT was generally thicker than the LT in all tooth types. The greatest mean value of labial concavity was observed for canines, compared to other tooth types. Men had a greater RT than did women, but had a comparable LT. Less apical fenestration was observed when tapered implants were used. Conclusions: Most teeth in the anterior maxilla had a thin labial bone plate, with no significant difference between sexes. Tapered implants may be advantageous for the anterior maxilla.

• Journal of Biomedical Engineering Research
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• v.29 no.2
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• pp.159-163
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• 2008

The goal of this study is to investigate the effect and potential of three-dimensional Co-culture of BMSCs (bone marrow stromal Cells) and NP (nucleus pulposus) Cells on the differentiation of BMSCs into NP-like Cells. The NP Cells and BMSCs were isolated and cultured from New Zealand White rabbits. The isolated NP Cells and BMSCs were prepared in different alginate beads. Those two types of beads were separated by a track-etched membrane of $3\;{\mu}m$ pore in a 6-well culture plate. No growth factors were used. In addition to these, NP and BMSC were cultured in the beads independently for control. The number of Cells in Co-culturing system was half of those in two control groups. Proliferation and production of glycosaminoglycan (GAG) were evaluated along with histological observation. The GAG production rate(GAG contents/Cell) of Co-cultured BMSCs were much higher than that of BMSCs cultured alone. The total amounts of GAG produced by BMSCs in Co-culturing system were larger than those produced by BMSCs in control group and were comparable with those produced by NP alone even the number of each Cell was half of BMSCs in Co-culturing system. This study showed the potential of differentiation of BMSCs into NP-like Cells through three-dimensional Co-culture system even without any chemical agents.

• The korean journal of orthodontics
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• v.46 no.5
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• pp.290-300
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• 2016

Objective: This study aimed to (1) evaluate the effects of maxillary second and third molar eruption status on the distalization of first molars with a modified palatal anchorage plate (MPAP), and (2) compare the results to the outcomes of the use of a pendulum and that of a headgear using three-dimensional finite element analysis. Methods: Three eruption stages were established: an erupting second molar at the cervical one-third of the first molar root (Stage 1), a fully erupted second molar (Stage 2), and an erupting third molar at the cervical one-third of the second molar root (Stage 3). Retraction forces were applied via three anchorage appliance models: an MPAP with bracket and archwire, a bone-anchored pendulum appliance, and cervical-pull headgear. Results: An MPAP showed greater root movement of the first molar than crown movement, and this was more noticeable in Stages 2 and 3. With the other devices, the first molar showed distal tipping. Transversely, the first molar had mesial-out rotation with headgear and mesial-in rotation with the other devices. Vertically, the first molar was intruded with an MPAP, and extruded with the other appliances. Conclusions: The second molar eruption stage had an effect on molar distalization, but the third molar follicle had no effect. The application of an MPAP may be an effective treatment option for maxillary molar distalization.

• International Journal of Oral Biology
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• v.30 no.2
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• pp.47-57
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• 2005

Leptin, the product of the obese gene, is a circulating hormone secreted primarily from adipocytes. Several results suggest that leptin is important mediators of bone metabolism. The present study was undertaken to determine the effects of leptin on anti-osteoclastogenesis using murine precursors cultured on Ca-P coated plates and on the production of osteoprotegerin (OPG) in osteoblastic cells. Additionally, this study examined the possible involvement of prostaglandin $E_2\;(PGE_2)$/protein kinase C (PKC)-mediated signals on the effect of leptin on anti-osteoclastogenesis to various culture systems of osteoclast precursors. Osteoclast generation was determined by counting tartrate-resistant acid phosphatase positive [TRAP (+)] multinucleated cells (MNCs). Osteoclastic activity was determined by measuring area of resorption pits formed by osteoclasts on Ca-P coated plate. The number of 1,25-dihydroxycholecalciferol $(1,25[OH]_2D_3)$- or $PGE_2$-induced TRAP (+) MNCs in the mouse bone marrow cell culture decreased significantly after treatment with leptin. The number of receptor activator of NF-kB ligand (RANKL)-induced TRAP (+) MNCs in M-CSF dependent bone marrow macrophage (MDBM) cell or RAW264.7 cell culture decreased significantly with leptin treatment. Indomethacin inhibited osteoclast generation induced by $1,25[OH]_2D_3$ and dexamethasone, however, no significant differences were found in the leptin treated group when compared to the corresponding indomethacin group. Phorbol 12-myristate 13-acetate (PMA), a PKC activator, inhibited osteoclast generation induced by $1,25[OH]_2D_3$. The number of TRAP (+) MNCs decreased significantly with treatment by PMA at concentrations of 0.01 and $0.1{\mu}M$ in culture. Leptin inhibited PMA-mediated osteoclast generation. Isoquinoline-5-sulfonic 2-methyl-1-piperazide dihydrochloride (H7) had no effect on osteoclast generation induced by $1,25[OH]_2D_3$. Cell culture treatment with leptin resulted in no significant differences in osteoclast generation compared to the corresponding H7 group. Indomethacin showed no significant effect on TRAP (+) MNCs formation from the RAW264.7 cell line. PMA inhibited TRAP (+) MNCs formation induced by RANKL in the RAW264.7 cell culture. H7 had no effect on osteoclast generation from the RAW264.7 cell line. There was no difference compared with the corresponding control group after treatment with leptin. $1,25[OH]_2D_3$- or $PGE_2$-induced osteoclastic activity decreased significantly with leptin treatment at a concentration of 100 ng/ml in mouse bone marrow cell culture. Indomethacin, PMA, and H7 significantly inhibited osteoclastic activity induced by $1,25[OH]_2D_3$ in mouse bone marrow cell culture. No significant differences were found between the leptin treated group and the corresponding control group. The secretion of OPG, a substance known to inhibit osteoclast formation, was detected from the osteoblasts. Treatment by leptin resulted in significant increases in OPG secretion by osteoblastic cells. Taken these results, leptin may be an important regulatory cytokines within the bone marrow microenvironment.

• Journal of Yeungnam Medical Science
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• v.4 no.2
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• pp.173-178
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• 1987

Osteogenic sarcoma is a malignant primary tumor of bone composed of a malignant connective tissue stroma with evidence of malignant osteoid, bone and/or cartilage formation. A 23year old man was admitted to dental department of Yeungnam University hospital with chief complaint of swelling and pain on alveolar ridge of lower right molar region. It was certain of osteogenic sarcoma through clinical and radiographic features and biopsy. Surgical resection of the lesion was performed by partial mandibulectomy and resin plate insertion. By follow up check of the patient, we made good result of functional reconstruction without any sign of recurrence of the lesion.

• Korean Journal of Cleft Lip And Palate
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• v.6 no.2
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• pp.91-105
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• 2003

There are significant limitations in the precision of mandibular distraction in setting a desired occlusal and facial esthetic outcome. The purpose of this study is to present the simulation method for the distraction osteogenesis treatment planning. 3-D surgery simulation software programs V-works and V-Surgery(Cybermed, Seoul, Korea) were used from the 3D CT data in addition to the conventional data facial photography, panorama and cephalogram, dental cast model. We have utilized already for the various surgical procedures to get information preoperatively for the maxillofacial surgery like cancer localization and reconstructive surgery, orthognathic surgery and implant surgery in the department of Oral and Maxillofacial surgery, Seoul National University Hospital. On the software, bone cutting can be done at any place and any direction. Separated bone segment can be mobilized in all 3 dimensional direction. After the 3D simulation on the software program, mock surgery on the RP model can be performed. This planning method was applied to two hemifacial microsomia patients. With this protocol, we could simulate the movement of bony segment after maxillofacial distraction osteogenesis

• Korean Journal of Cleft Lip And Palate
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• v.16 no.1
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• pp.1-8
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• 2013

Purpose : To introduce a more effective and efficient protocol for protraction of maxillary complex in CLP patient and demonstrate it by case presentation. Methods : Miniplates are placed on zygomatic buttress and anterior part of mandible, at the time of secondary alveolar bone graft. During the night time, the orthopedic force is applied by wearing elastics from maxillary miniplates to facemask (500 g per side). During the day time, the intermaxillary elastics connecting maxillary miniplates to mandibular miniplates are applied (200 g per side). During the orthopedic treatment, dental alignment is possible. Results and conclusion : By the new protocol, the intermaxillary relation and occlusion are improved due to the stable intraoral anchorage and better cooperation of patients.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.36 no.4
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• pp.154-160
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• 2014

Purpose: The efficiency of an anchor plate placed during orthognathic surgery via minimal presurgical orthodontic treatment was evaluated by analyzing the mandibular relapse rate and dental changes. Methods: The subjects included nine patients with Class III malocclusion who had bilateral sagittal split osteotomy at the Division of Oral and Maxillofacial Surgery, Department of Dentistry in Ajou University Hospital, after minimal presurgical orthodontic treatment. During orthognathic surgery, anchor plates were placed at both maxillary buttresses. The anchor plates were used to move maxillary teeth backward and for maximum anchorage of Class III elastics to minimize mandibular relapse during the postoperative orthodontic treatment. The lateral cephalometric X-ray was taken preoperatively (T0), postoperatively (T1), and one year after the surgery (T2). Seven measurements (distance from Pogonion to line Nasion-Nasion perpendicular [Pog-N Per.], angle of line B point-Nasion and Nasion-Sella [SNB], angle of line maxilla 1 root-maxilla 1 crown and Nasion-Sella [U1 to SN], distance from maxilla 1 crown to line A point-Nasion [U1 to NA], overbite, overjet, and interincisal angle) were taken. Measurements at T0 to T1 and T1 to T2 were compared and differences tested by standard statistical methods. Results: The mean skeletal change was posterior movement by $13.87{\pm}4.95mm$ based on pogonion from T0 to T1, and anterior movement by $1.54{\pm}2.18mm$ from T1 to T2, showing relapse of about 10.2%. There were significant changes from T0 to T1 for both Pog-N Per. and SNB (P<0.05). However, there were no statistically significant changes from T1 to T2 for both Pog-N Per. and SNB. U1 to NA that represents the anterior-posterior changes of maxillary incisor did not differ from T0 to T1, yet there was a significant change from T1 to T2 (P<0.05). Conclusion: This study found that the anchor plate minimizes mandibular relapse and moves the maxillary teeth backward during the postoperative orthodontic treatment. Thus, we conclude that the anchor plate is clinically very useful.

• The korean journal of orthodontics
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• v.48 no.2
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• pp.113-124
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• 2018

The purpose of this case report was to introduce the concept of orthodontic and orthopedic treatment for a growing patient with Tessier number 0 cleft. A 5-year-old boy patient with Tessier number 0 cleft presented congenitally missing maxillary central incisors (MXCI), a bony defect at the premaxilla, a constricted maxillary arch, an anterior openbite, and maxillary hypoplasia. His treatment was divided into three stages: management of the bony defect at the premaxilla and the congenitally missing MXCIs using a fan-type expansion plate, iliac bone grafting, and eruption guidance of the maxillary lateral incisors into the graft area for substitution of MXCIs; management of the maxillary hypoplasia using sequential facemask therapy with conventional and skeletal anchorage; and management of the remaining occlusal problems using fixed orthodontic treatment. The total treatment duration was 15 years and 10 months. Class I canine and Class II molar relationships and normal overbite and overjet were achieved at the end of treatment. Although the long-term use of facemask therapy resulted in significant protraction of the retrusive maxilla, the patient exhibited Class III profile because of continued mandibular growth. However, the treatment result was well maintained after 2 years of retention. The findings from this case suggest that interdisciplinary and customized approaches are mandatory for successful management of maxillary hypoplasia, bony defect, and dental problems in Tessier number 0 cleft. Moreover, considering the potential of orthognathic surgery or distraction osteogenesis, meticulous monitoring of mandibular growth until growth completion is important.

• Journal of Dental Rehabilitation and Applied Science
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• v.24 no.4
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• pp.361-369
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• 2008

The purpose of this study is to make porous oxide film on the surfaces of pure Ti through anodic spark discharge in electrolytic solution containing calcium and phosphate ions, to improve osseointergration by treating fluoride agent. In addition, it is to evaluate the fluoride modified effect on the surface. Commercial pure Ti plate with $20{\times}10{\times}2mm$ and Ti wire with a diameter of 1.5mm and a total length of 15mm were used. After making titanium oxide films converted by anodic spark discharge, anodizing was performed. Fluoride was spreaded to titanium laboratory plate and maintained for 30 minutes after anodizing breakdown. Fluoride ion discharge amount was measured per 24 hours after dipping titanium plate into saline (10ml) and sustaining 90rpm in a pyrostat. Some plates and wires were dipped in Hanks solutions for a month to examine biocompatibility using SEM and XRD. $TiO_2$ film formed by anodic discharge technique showed great roughness and uniform pores which were $1{\sim}3{\mu}m$ in a diameter. Roughness of the films treated with anodic discharge after blasting were higher than the turned ones(P<0.05). Rapid surface activity was observed in the samples treated with $TiF_3$ agent, which immersed in Hanks solution for 30 days. Taking the results into consideration, the fluoride modified implant with anodic discharge demonstrates that it makes uniformly porous oxide film on the surface of implant and properly increase roughness for osseointegration. The implants will achieve greater bone integration after short healing time by improving surface activity.