• Journal of Periodontal and Implant Science
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• v.32 no.1
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• pp.161-172
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• 2002

The present study evaluated the effects of guided tissue regeneration using xenograft material(deproteinated bovine bone powder), with and without biodegradable membrane in beagle dogs. Contralateral fenestration defects (6 ${\times}$ 4mm) were created 4 mm apical to the buccal alveolar crest of maxillary premolar teeth in 5 beagle dogs. Deproteinated bovine bone powders were implanted into fenestration defect and one randomly covered biodegradable membrane (experimental group). Biodegradable membrane was used to provide GTR. Tissue blocks including defects with soft tissues which were harvested following four & eight weeks healing interval, prepared for histo-phathologic analysis. The results of this study were as follows. 1. In control group, at 4 weeks after surgery, new bony trabecular contacted with interstitial tissue and osteocytes like cell were arranged in new bony trabecule. Bony lamellation was not observed. 2. In control gruop, at 8 weeks after surgery, scar-like interstitial tissue was filled defect and bony trabecule form lamellation. New bony trabecular was contacted with interstitial tissue but defect was not filled yet. 3. In experimental group, at 4 weeks after surgery, new bony trabecular partially recovered around damaged bone. But new bony trabecular was observed as irregularity and lower density. 4. In experimental group, at 8 weeks after surgery, lamella bone trabecular developed around bone cavity and damaged tissue was replaced with dense interstitial tissue. In conclusion, new bone formation regenerated more in experimental than control groups and there was seen observe more regular bony trabecular in experimental than control groups at 4 weeks after surgery. In control group, at 8 weeks after surgery, the defects was filled with scar-like interstitial tissue but, in experimental group, the defects was connected with new bone. Therefore xenograft material had osteoconduction but could not fill the defects. We thought that the effective regeneration of periodontal tissue, could be achieved using GTR with biodegradable membrane.

• Restorative Dentistry and Endodontics
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• v.24 no.1
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• pp.166-179
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• 1999

Apical sealing is essential for the success of surgical endodontic treatment. Root-end cavity is apt to be contaminated with moisture or blood, and is not always easy to be dried completely. The purpose of this study was to evaluate the influence of dry methods of retrocavity on the apical seal in endodontic surgery. Apical seal was investigated through the evaluation of apical leakage and adaptation of filling material over the cavity wall. To investigate the influence of various dry methods on the apical leakage, 125 palatal roots of extracted human maxillary molar teeth were used. The clinical crown of each tooth was removed at 10 mm from the root apex using a slow-speed diamond saw and water spray. Root canals of the all the specimens were prepared with step-back technique and filled with gutta-percha by lateral condensation method. After removing of the coronal 2 mm of filling material, the access cavities were closed with Cavit$^{(R)}$. Two coats of nail polish were applied to the external surface of each root. Apical three millimeters of each root was resected perpendicular to the long axis of the root with a diamond saw. Class I retrograde cavities were prepared with ultrasonic instruments. Retrocavities were washed with physiologic saline solution and dried with various methods or contaminated with human blood. Retrocavities were filled either with IRM, Super EBA or composite resin. All the specimens were immersed in 2% methylene blue solution for 7 days in an incubator at $37^{\circ}C$. The teeth were dissolved in 14 ml of 35% nitric acid solution and the dye present within the root canal system was returned to solution. The leakage of dye was quantitatively measured via spectrophotometric method. The obtained data were analysed statistically using one-way ANOVA and Duncan's Multiple Range Test. To evaluate the influence of various dry methods on the adaptation of filling material over the cavity wall, 12 palatal roots of extracted human maxillary molar teeth were used. After all the roots were prepared and filled, and retrograde cavities were made and filled as above, roots were sectioned longitudinally. Filling-dentin interface of cut surfaces were examined by scanning electron microscope. The results were as follows: 1. Cavities dried with paper point or compressed air showed less leakage than those dried with cotton pellet in Super EBA filled cavity (p<0.05). However, there was no difference between paper point- and compressed air-dried cavities. 2. When cavities were dried with compressed air, dentin-bonded composite resin-filled cavities showed less apical leakage than IRM- or Super EBA-filled ones (p<0.05). 3. Regardless of the filling material, cavities contaminated with human blood showed significantly more apical leakage than those dried with compressed air after saline irrigation (p<0.05). 4. Outer half of the cavity showed larger dentin-filling interface gap than inner half did when cavities were filled with IRM or Super EBA. 5. In all the filling material groups, cavities contaminated with blood or dried with cotton pellets only showed larger defects at the base of the cavity than ones dried with paper points or compressed air.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.35 no.4
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• pp.260-264
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• 2013

Calcium hydroxide root canal filing paste (vitapex) is widely used as canal filling paste for infected canal. However, chemical burn is possible because of the high alkali base of calcium hydroxide. A 57-year old woman was admitted to our clinic for consistent dull pain and paresthesia in the left upper lip, zygoma and buccal cheek area, which developed during an endodontic treatment of the left lateral incisor. Radiographic finding showed radiopaque material, which exits from the left incisor root apex, and was within the left canine and first premolar buccal soft tissue. The overfilled Vitapex extended to the soft tissue was surgically curetted. The result of the surgical curettage was favorable. Though slight hypoesthesia on the upper lip was still remained, paresthesia on zygomatic and buccal cheek area was completely recovered. As far as we know, this is the first case report of infraorbital nerve damage from overfilled Vitapex material.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.40 no.4
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• pp.173-180
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• 2014

Objectives: The purpose of this study was to investigate the neurogenic differentiation of human dental pulp stem cells (DPSCs), periodontal ligament stem cells (PDLSCs), and stem cells from apical papilla (SCAP). Materials and Methods: After induction of neurogenic differentiation using commercial differentiation medium, expression levels of neural markers, microtubule-associated protein 2 (MAP2), class III ${\beta}$-tubulin, and glial fibrillary acidic protein (GFAP) were identified using reverse transcriptase polymerase chain reaction (PCR), real-time PCR, and immunocytochemistry. Results: The induced cells showed neuron-like morphologies, similar to axons, dendrites, and perikaryons, which are composed of neurons in DPSCs, PDLSCs, and SCAP. The mRNA levels of neuronal markers tended to increase in differentiated cells. The expression of MAP2 and ${\beta}$-tubulin III also increased at the protein level in differentiation groups, even though GFAP was not detected via immunocytochemistry. Conclusion: Human dental stem cells including DPSCs, PDLSCs, and SCAP may have neurogenic differentiation capability in vitro. The presented data support the use of human dental stem cells as a possible alternative source of stem cells for therapeutic utility in the treatment of neurological diseases.

• Archives of Craniofacial Surgery
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• v.9 no.2
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• pp.93-96
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• 2008

Purpose: Sudoriferous cyst usually occurs on the face, and especially on the ear and scalp as a solitary cystic mass. It is derived from the sweat glands of Moll and results from the obstruction of excretory ducts with the retention of fluid. In the eyelid, it is usually seen as small and firm vesicle arising at the eyelid margin. If it rarely occurs on the orbit, it develops from orbital ectopic epithelial cells predetermined to form glands of Moll. We experienced a case of sudoriferous cyst on eyelid which was adhered to levator aponeurosis and it disappeared when patient closed eyes. Methods: A 55-year-old women suffered palpable mass on left upper eyelid without pain that had been present for 25 years. Orbital computed tomographic finding showed a oval mass($2.1{\times}0.6{\times}0.6cm$ size) inside upper eyelid and it invaded the orbit. The mass was completely excised under general anesthesia and histopathological examination was followed. Results: Cystic mass was purple color and it was located in superiorly to tarsal plate. The mass was adhered to levator aponeurosis and levator palpabrae superioris muscle between the fat layer of post-orbital septum and the Whitnall ligament. The mass was completely excised without injury of aponeurosis and muscle. Microscopically, the lesion was a solitary cyst lined by two layers of cuboidal epithelial cells and innermost cells displaying eosinophilic cytoplasm with apical expansions. Conclusion: Sudoriferous cyst usually occurs on eyelid margin. But in this case, cystic mass occurred on upper eyelid and disappeared when patient closed the eyes because it was partially adhered to levator aponeurosis and levator palpebrae superioris muscle. Therefore, if sudoriferous cyst occurs on eyelid, it is necessary to excised the mass carefully.

• Advances in biomechanics and applications
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• v.1 no.1
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• pp.41-55
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• 2014

Acellular intra-myocardial biomaterial injections have been shown to be therapeutically beneficial in inhibiting ventricular remodelling of myocardial infarction (MI). Based on a biventricular canine cardiac geometry, various finite element models were developed that comprised an ischemic (II) or scarred infarct (SDI) in left ventricular (LV) antero-apical region, without and with intra-myocardial biomaterial injectate in layered (L) and bulk (B) distribution. Changes in myocardial properties and LV geometry were implemented corresponding to infarct stage (tissue softening vs. stiffening, infarct thinning, and cavity dilation) and injectate (infarct thickening). The layered and bulk injectate increased ejection fraction of the infarcted LV by 77% (II+L) and 25% (II+B) at the ischemic stage and by 61% (SDI+L) and 63% (SDI+B) at the remodelling stage. The injectates decreased the mean end-systolic myofibre stress in the infarct by 99% (II+L), 97% (II+B), 70% (SDI+L) and 36% (SDI+B). The bulk injectate was slightly more effective in improving LV function at the remodelling stage whereas the layered injectate was superior in functional improvement at ischemic stage and in reduction of wall stress at ischemic and remodelling stage. These findings may stimulate and guide further research towards tailoring acellular biomaterial injectate therapies for MI.

• Journal of Chest Surgery
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• v.36 no.7
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• pp.518-522
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• 2003

Left ventricular thrombosis is a frequent and potentially dangerous complication in acute myocardiac infarction, but its occurrence and adequate therapy has not been known in patients with Dor procedure for the ischemic cardiomyopathy. We report a patient, 45 year-old male, who had a new left ventricular thrombus developed after coronary arterial bypass graft, Dor procedure, and removal of the left ventricular thrombus for ischemic car-diomyopathy. Left ventricular thrombus was disappeared on the follow-up cardiac MRI following intravenous heparin injection and oral coumadin therapy. This case suggest that anticoagulation therapy may prevent patients with the severe left ventricular dysfunction and apical aneurysm and dyskinesia from developing the left ventricular thrombus, and that thrombi will resolve without clinical evidence of systemic embolism.

• Journal of Chest Surgery
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• v.42 no.1
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• pp.72-78
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• 2009

Background: Mediastinal neurogenic tumors are generally benign lesions and they are ideal candidates for performing resection via video-assisted thoracoscopic surgery (VATS). However, benign neurogenic tumors at the thoracic apex present technical problems for the surgeon because of the limited exposure of the neurovascular structures, and the optimal way to surgically access these tumors is still a matter of debate. This study aims to clarify the feasibility and safety of the VATS approach for performing surgical resection of benign apical neurogenic tumors (ANT). Material and Method: From January 1996 to September 2008, 31 patients with benign ANT (15 males/16 females, mean age: 45 years, range: 8~73), were operated on by various surgical methods: 14 VATS, 10 lateral thoracotomies, 6 cervical or cervicothoracic incisions and 1 median sternotomy. 3 patients had associated von Recklinhausen's disease. The perioperative variables and complications were retrospectively reviewed according to the surgical approaches, and the surgical results of VATS were compared with those of the other invasive surgeries. Result: In the VATS group, the histologic diagnosis was schwannoma in 9 cases, neurofibroma in 4 cases and ganglioneuroma in 1 case, and the median tumor size was 4.3 cm (range: 1.2~7.0 cm). The operation time, amount of chest tube drainage and the postoperative stay in the VATS group were significantly less than that in the other invasive surgical group (p<0.05). No conversion thoracotomy was required. There were 2 cases of Hornor's syndrome and 2 brachial plexus neuropathies in the VATS group; there was 1 case of Honor's syndrome, 1 brachial plexus neuropathy, 1 vocal cord palsy and 2 non-neurologic complications in the invasive surgical group, and all the complications developed postoperatively. The operative method was an independent predictor for postoperative neuropathies in the VATS group (that is, non-enucleation of the tumor) (p=0.029). Conclusion: The VATS approach for treating benign ANT is a less invasive, safe and feasible method. Enucleation of the tumor during the VATS procedure may be an important technique to decrease the postoperative neurological complications.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.37 no.5
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• pp.406-414
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• 2011

Thermally induced bone necrosis during implant surgery is a rare phenomenon and a potential contributing factor to implant failure. The frictional heat generated at the time of surgery causes a certain degree of necrosis of the surrounding differentiated and undifferentiated cells. The bone necrosis occurred in the mandible in all three cases, leading to a soft tissue lesion and pain. In each case, radiolucent areas appeared in the middle and apical portions of the implant 4 weeks after surgery. Thermally induced bone necrosis did not improve following systemic antibiotic medication, necessitating surgical treatment. The nonintegrated implants were removed, and meticulous debridement of dead bone and granulation tissue was performed. Then, new implants were implanted along with the placement of autogenous and xenogenic bone covered with a collagen membrane. No further complications occurred after re-operation. The radiolucencies around the new implants gradually resolved entirely, and the soft tissue lesions healed successfully. At 4-5 months after reoperation, implant loading was initiated and the implant-supported restorations have been functioning. The aim of this case report is to present the successful clinical treatment of three cases suspected to be caused by thermally induced bone necrosis after implant drilling.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.2
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• pp.150-160
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• 2005

Background: For normalization of displaced anatomical structure by large cyst, two-step procedure (decompression and enucleation afterward) has been recommended. However, the histological transformation after cystotomy for decompression was shown frequently in secondary enucleation. Therefore, analyses about effects and histological changes after decompression have been necessary. Methods: 48 cases diagnosed as large odontogenic cyst in the jaw and treated by decompression and secondary enucleation were retrospectively analyzed in clinical, rediographical, and histological aspects. Results: In dentigerous cyst, decompression was much useful. Impacted permanent teeth were erupted and reduction rate was higher than that of odontogenic keratocyst (OKC) and apical periodontal cyst. In OKC, among the 29 cases, 11 cases showed no-keratosis, proliferation and rete-ridge elongation after decompression. 4 cases showed no-keratosis, only. 7 cases showed orthokeratosis and rete-ridge elongation and 6 cases showed reteridge elongation, only. 1 case had no change. And the recurrence rate for OKCs was 10.3%. For all odontogenic cysts in this study, dysplasia was not found in cystic lining after decompression. Conclusions: This study implied that decompression for large odontogenic cyst was useful treatment modality because it was conservative treatment and recurrence rate was low although long treatment period was required.