1.Strategic serial extractions and immediate implantation for interdental papilla preservation: A case report.
Geun Bae CHOI ; Jung Jin LEE ; Seung Geun AHN ; Jae Min SEO
The Journal of Korean Academy of Prosthodontics 2017;55(3):286-291
Maintaining the blood supply of the interdental alveolar bone is crucial for preserving the interdental papilla. Rebuilding the interimplant papilla between adjacent implants is more difficult than rebuilding the interdental papilla between the natural tooth and implant. Therefore, preserving the interimplant tissue is necessary when adjacent implants are closely placed. In this case report, three effective methods for maintaining the surrounding tissue, namely strategic serial extraction, immediate implantation, and provisionalization of adjacent maxillary central incisors, were performed. The marginal gingiva and interimplant papilla were well maintained for 24 months.
Gingiva*
;
Incisor
;
Serial Extraction*
;
Tooth
2.Multiple Plexiform Schwannomas Associated with Neurofibromatosis Type 2: A case report.
Ho Sung PARK ; Myoung Ja CHUNG ; Myoung Jae KANG ; Dong Geun LEE ; Byung Cook AHN
Korean Journal of Pathology 2000;34(5):389-392
Plexiform schwannoma is a rare benign tumor arising from the peripheral nerve sheath and characterized by a multinodular and plexiform growth pattern. This tumor usually arises sporadically. In rare cases, plexiform schwannomas have been associated with neurofibromatosis type 2. Plexiform schwannoma should be differentiated from plexiform neurofibroma, because the latter is pathognomonic tumor of neurofibromatosis type 1 and has a potential of malignant transformation. We report a case of multiple plexiform schwannomas associated with bilateral acoustic neuromas and meningioma.
Meningioma
;
Neurilemmoma*
;
Neurofibroma, Plexiform
;
Neurofibromatoses*
;
Neurofibromatosis 1
;
Neurofibromatosis 2*
;
Neuroma, Acoustic
;
Peripheral Nerves
3.Effect of impression coping and implant angulation on the accuracy of implant impressions: an in vitro study.
Si Hoon JO ; Kyoung Il KIM ; Jae Min SEO ; Kwang Yeob SONG ; Ju Mi PARK ; Seung Geun AHN
The Journal of Advanced Prosthodontics 2010;2(4):128-133
PURPOSE: The purpose of this study was to compare the accuracy of the implant master cast according to the type (pick-up, transfer) and the length (long, short) of the impression copings. MATERIALS AND METHODS: The metal master cast was fabricated with three internal connection type implant analogs (Osstem GS III analog), embedded parallel and with 10degrees of mesial angulation to the center analog. Four types of impression coping were prepared with different combinations of types (transfer, pick-up) and lengths (long, short) of the coping. The impressions were made using vinyl polysiloxane (one step, heavy + light body) with an individual tray, and 10 impressions were made for each group. Eventually, 40 experimental casts were produced. Then, the difference in the distance between the master cast and the experimental cast were measured, and the error rate was determined. The analysis of variance was performed using the SPSS (v 12.0) program (alpha = .05), and the statistical significance was set at P < .05. RESULTS: The ANOVA showed that the pick-up type impression coping exhibited a significantly lower error rate than the transfer type. However, no significant difference was observed with respect to the length of the impression coping. Additionally, no significant difference was observed between the parallel and mesial angulated groups. CONCLUSION: Within the limitations of this study, the pick-up type impression coping exhibited a more accurate implant master cast than the transfer type in parallel group. The accuracy of the implant master cast did not differ for different lengths of impression coping of at least 11 mm. Additionally, the accuracy of the implant cast was not different for the parallel and 10degrees mesial angulated groups.
Light
;
Polyvinyls
;
Siloxanes
4.Effects of hydrofluoric acid concentration and etching time on the shear bond strength between lithium disilicate ceramic and resin cement.
Jae Min SEO ; Charn Woon PARK ; Seung Geun AHN
The Journal of Korean Academy of Prosthodontics 2007;45(4):407-418
PURPOSE: The objective of this study was to evaluate the effects of hydrofluoric acid concentration & etching time on the shear bond strength between IPS Empress 2 ceramic and resin cement. MATERIAL AND METHODS: Thirty three rectangular shape ceramic specimens(20x12x5mm size, IPS Empress 2 core materials) were used for this study. The ceramic specimens divided into ten experimental groups with three specimens in each group and were etched with hydrofluoric acid(4%, 9%) according to different etching times(30s, 60s, 90s, 120s, 180s). Etched surfaces of ceramic specimens were bonded with resin cement(Rely X Unicem) using acrylic glass tube. All cemented specimens were tested under shear loading until fracture on universal testing machine at a crosshead speed of 0.5mm/min and the maximum load at fracture(kg) was recorded. Collected shear bond strength data were analyzed with one way ANOVA and Duncan tests. All etched ceramic surfaces were examined morphologically using SEM(scanning electron microscopy). RESULTS: Shear bond strength of etching group(35.89~68.01 MPa) had four to seven times greater than no-etching group(9.53+/-2.29 MPa). The ceramic specimen etched with 4% hydrofluoric acid for 60s showed the maximum shear bond strength(68.01+/-11.78 MPa). Ceramic surface etched with 4% hydrofluoric acid for 60s showed most retentive surface texture. CONCLUSION: It is considered that 60s etching with 4% hydrofluoric acid is optimal etching methods for IPS Empress 2 ceramic bonding.
Ceramics*
;
Glass
;
Hydrofluoric Acid*
;
Lithium*
;
Resin Cements*
5.A Cases of Retroperitoneal Immature Teratoma(Grade III).
A Ellen KIM ; Hee Ju KIM ; Jae Sun JUNG ; Sung Ill AHN ; Hye Kyung LEE ; Je Geun CHI
Journal of the Korean Pediatric Society 1987;30(3):327-334
No abstract available.
6.Clinical Experience of the Brushite Calcium Phosphate Cement for the Repair and Augmentation of Surgically Induced Cranial Defects Following the Pterional Craniotomy.
Journal of Korean Neurosurgical Society 2010;47(3):180-184
OBJECTIVE: To prevent temporal depression after the pterional craniotomy, this study was designed to examine the safety and aesthetic efficacy of the brushite calcium phosphate cement (CPC) in the repair and augmentation of bone defects following the pterional craniotomy. METHODS: The brushite CPC was used for the repair of surgically induced cranial defects, with or without augmentation, in 17 cases of pterional approach between March, 2005 and December, 2006. The average follow-up month was 20 with range of 12-36 months. In the first 5 cases, bone defects were repaired with only brushite CPC following the contour of the original bone. In the next 12 cases, bone defects were augmented with the brushite CPC rather than original bone contour. For a stability monitoring of the implanted brushite CPC, post-implantation evaluations including serial X-ray, repeated physical examination for aesthetic efficacy, and three-dimensional computed tomography (3D-CT) were taken 1 year after the implantation. RESULTS: The brushite CPC paste provided precise and easy contouring in restoration of the bony defect site. No adverse effects such as infection or inflammation were noticed during the follow-up periods from all patients. 3D-CT was taken 1 year subsequent to implantation showed good preservation of the brushite CPC restoration material. In the cases of the augmentation group, aesthetic outcomes were superior compared to the simple repair group. CONCLUSION: The results of this clinical study indicate that the brushite CPC is a biocompatible alloplastic material, which is useful for prevention of temporal depression after pterional craniotomy. Additional study is required to determine the long-term stability and effectiveness of the brushite calcium phosphate cement for the replacement of bone.
Calcium
;
Calcium Phosphates
;
Craniotomy
;
Depression
;
Dinucleoside Phosphates
;
Follow-Up Studies
;
Humans
;
Inflammation
;
Physical Examination
7.Infraoptic Course of Both Anterior Cerebral Arteries.
Journal of Korean Neurosurgical Society 2010;47(1):71-73
A 28-year-old woman was referred to our hospital with a sudden, very severe headache. Brain computed tomographic angiography showed a saccular cerebral aneurysm at the bifurcation of the left middle cerebral artery and infraoptic courses of both anterior cerebral arteries. The anterior cerebral arteries were seen to arise from the ipsilateral internal cerebral arteries at the level of the origin of the ophthalmic artery, passed underneath the ipsilateral optic nerve, and turned upward at ventral portion of the optic chiasm.
Adult
;
Angiography
;
Anterior Cerebral Artery
;
Brain
;
Cerebral Arteries
;
Female
;
Headache
;
Humans
;
Intracranial Aneurysm
;
Middle Cerebral Artery
;
Ophthalmic Artery
;
Optic Chiasm
;
Optic Nerve
9.Leukotriene B4 pathway regulates the fate of the hematopoietic stem cells.
Jin Woong CHUNG ; Geun Young KIM ; Yeung Chul MUN ; Ji Young AHN ; Chu Myong SEONG ; Jae Hong KIM
Experimental & Molecular Medicine 2005;37(1):45-50
Leukotriene B4(LTB4), derived from arachidonic acid, is a potent chemotactic agent and activating factor for hematopoietic cells. In addition to host defense in vivo, several eicosanoids have been reported to be involved in stem cell differentiation or proliferation. In this study, we investigated the effect of LTB4 on human cord blood CD34+ hematopoietic stem cells (HSCs). LTB4 was shown to induce proliferation of HSC and exert anti-apoptotic effect on the stem cells. Blockade of interaction between LTB4 and its receptor enhanced self-renewal of the stem cells. Effect of LTB4 on differentiation of CD34+ HSCs were confirmed by clonogenic assays, and induction of the expression of BLT2 (the low- affinity LTB4 receptor), during the ex vivo expansion was confirmed by reverse transcription-PCR. Our results suggest that LTB4-BLT2 interaction is involved in the cytokine-induced differentiation and ex vivo expansion of hematopoietic stem cells.
Antigens, CD34/metabolism
;
Apoptosis/drug effects
;
Cell Differentiation/drug effects
;
Cell Proliferation/drug effects
;
Fetal Blood/cytology/drug effects
;
Hematopoietic Stem Cells/*drug effects/metabolism
;
Humans
;
Leukotriene B4/*pharmacology
;
Receptors, Leukotriene B4/genetics/metabolism
;
Research Support, Non-U.S. Gov't
;
Reverse Transcriptase Polymerase Chain Reaction
;
*Signal Transduction
10.Primary Radiation Therapy of Polymorhic Reticulosis.
Jae Sung KIM ; Yong Chan AHN ; Hyoung Geun YUN ; Charn Il PARK
Journal of the Korean Society for Therapeutic Radiology 1991;9(1):111-116
From 1979 to 1987, 33 patients with polymorphic retrculosis (PMR) limited in the upper airway were treated with primary radiation therapy and the analysis of treatment results was undertaken. Systemic symptoms such as fever, night sweats, and weight loss were noted in 48%. The nasal cavity was most frequently involved (85%), although involvement of PNS (33%) and palate (30%) was not uncommon. The 5 and 10 year actuarial survival rates were 47% and 40%, respectively. The difference in NSD between patients with in-field failure and those without it was significant statistically. Also, field size was significantly smaller in patients with marginal failure than those without it. During the follow-up period, systemic failure was found in 5 patients (diffuse histiocytic lymphoma in 4, histiocytic medullary retriculosis in 1). In this study, we can suggested that total radiation dose of at least 4500 cGy with generous treatment volume should be delivered to achieve better local control and that the development of an effective systemic chemotherapeutic regimen is required to improve the survival after systemic relapse.
Fever
;
Follow-Up Studies
;
Granuloma, Lethal Midline
;
Humans
;
Lymphoma, Large B-Cell, Diffuse
;
Nasal Cavity
;
Palate
;
Radiotherapy
;
Recurrence
;
Survival Rate
;
Sweat
;
Weight Loss