• Implantology
• /
• v.22 no.4
• /
• pp.242-254
• /
• 2018

The aim of the current study was to evaluate the results of horizontal guided bone regeneration (GBR) with xenograf t (deproteinized bovine bone mineral, DBBM), allograf t (irradiated allogenic cancellous bone and marrow), titanium membrane, resorbable collagen membrane, and advanced platelet-rich fibrin (A-PRF) in the anterior maxilla. The titanium membrane was used in this study has a three-dimensional (3D) shape that can cover ridge defects. Case 1. A 32-year-old female patient presented with discomfort due to mobility and pus discharge on tooth #11. Three months after extracting tooth #11, diagnostic software (R2 GATE diagnostic software, Megagen, Daegu, Korea) was used to establish the treatment plan for implant placement. At the first stage of implant surgery, GBR for horizontal augmentation was performed with DBBM ($Bio-Oss^{(R)}$, Geistlich, Wolhusen, Switzerland), irradiated allogenic cancellous bone and marrow (ICB $cancellous^{(R)}$, Rocky Mountain Tissue Bank, Denver, USA), 3D-titanium membrane ($i-Gen^{(R)}$, Megagen, Daegu, Korea), resorbable collagen membrane (Collagen $membrane^{(R)}$, Genoss, Suwon, Korea), and A-PRF because there was approximately 4 mm labial dehiscence after implant placement. Five months after placing the implant, the second stage of implant surgery was performed, and healing abutment was connected after removal of the 3D-titanium membrane. Five months after the second stage of implant surgery was done, the final prosthesis was then delivered. Case 2. A 35-year-old female patient presented with discomfort due to pain and mobility of implant #21. Removal of implant #21 fixture was planned simultaneously with placement of the new implant fixture. At the first stage of implant surgery, GBR for horizontal augmentation was performed with DBBM ($Bio-Oss^{(R)}$), irradiated allogenic cancellous bone and marrow (ICB $cancellous^{(R)}$), 3D-titanium membrane ($i-Gen^{(R)}$), resorbable collagen membrane (Ossix $plus^{(R)}$, Datum, Telrad, Israel), and A-PRF because there was approximately 7 mm labial dehiscence after implant placement. At the second stage of implant surgery six months after implant placement, healing abutment was connected after removing the 3D-titanium membrane. Nine months after the second stage of implant surgery was done, the final prosthesis was then delivered. In these two clinical cases, wound healing of the operation sites was uneventful. All implants were clinically stable without inflammation or additional bone loss, and there was no discomfort to the patient. With the non-resorbable titanium membrane, the ability of bone formation in the space was stably maintained in three dimensions, and A-PRF might influence soft tissue healing. This limited study suggests that aesthetic results can be achieved with GBR using 3D-titanium membrane and A-PRF in the anterior maxilla. However, long-term follow-up evaluation should be performed.

• The Journal of Korea Assosiation for Disability and Oral Health
• /
• v.6 no.2
• /
• pp.94-98
• /
• 2010

Axenfeld-Rieger syndrome is a rare autosomal dominant disorder characterized by various ocular and extraocular malformations. The incidence of Axenfeld-Rieger syndrome has been estimated to be 1 per 200,000. The syndrome is characterized by short body stature, delayed bone age, and deficient or arrested development of neural crest cells involving the anterior chamber of the eyes, facial bones, teeth, periumbilical skin, and cardiovascular system. This is a case of a 6 year-old girl, who came to the department of the pediatric dentistry, Yonsei University Dental Hospital, for evaluation and treatment of multiple congenital missing permanent teeth. The patient presented typical dental, craniofacial, and systemic features of Axenfeld-Rieger syndrome, such as glaucoma, oval pupil, heterochromatic iris, umbilical hernia, and delayed bone age. On the panoramic view, 3 primary teeth were missing and 13 permanent tooth germs were absent. On the lateral cephalograph, underdevelopment of the maxilla and normal growth pattern of the mandible were confirmed. Periodic dental follow-up is planned for evaluation and interceptive treatment of her dental and craniofacial problems. Denture or removable space maintainer with a pontic is considered for esthetic and functional restoration. In addition, orthognathic surgery is also planned in future to prevent further midfacial skeletal deformation. Early diagnosis of Axenfeld-Rieger syndrome is very important to prevent exacerbation of complications, such as glaucoma and skeletal deformities.

• The korean journal of orthodontics
• /
• v.31 no.2 s.85
• /
• pp.199-207
• /
• 2001

The segmented TMA T-loop spring, used for reciprocal space closure and described by Burstone, was used to achievebodily movement of canine. Photoelastic analysis is a technique for the transformation of internal stress into visible light patterns. The two-dimensional photoelastic stress analysis was performed, and stress distribution was recorded by photography. The purpose of this study was to visualize photoelastically the distribution of forces transmitted to the alveolus and surrounding structures using new segmented TMA T-loop spring for canine retraction. The results were as follows: 1. Decreased activation produced decreased stress of upper 1st. premolar extraction site and increased intrusive stress of upper 1st. molar, regardless of T-loop position. 2. At 5mm activation, More posterior positioning of T-loop Produced an increased stress in upper 1st. premolar extraction site. 3. At 3mm activation, More posterior positioning of T-loop produced an increased stress in upper 1st. premolar extraction site and mesial lower half of upper 1st. molar mesio-buccal root. 4. At 1mm activation, More anterior positioning of T-loop produced an increased stress in upper mesial and blew apex area of upper canine root. 5. 0.25 B/L ratio and 3mm activation produced bodily movement of canine. To summarize, desired tooth movement and anchorage requirement is possible by altering the activation and mesio-distal position of the T-loop spring.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.44 no.2
• /
• pp.235-242
• /
• 2017

Marsupialization and decompression constitute a well-established procedure for treating cavitary bone lesions of the jaw. The technique can be a primary treatment option, especially for pediatric patients with large cysts or lesions involving vital anatomical structures, such as a developing tooth germ. In this procedure, a decompression stent, such as a customized acrylic obturator or space-maintaining appliance, silicone tube, or nasal cannula, is inserted to maintain the patency of the cyst. However, this may cause clinical problems, such as irritation or trauma to the adjacent tissues, as well as discomfort to the patient, or failure of the stent due to cyst shrinkage. It can also be a reason for patient noncompliance. In the cases described here, a minimally invasive marsupialization technique using a metal tube made from a 16-gauge needle was used for odontogenic cysts in pediatric patients associated with unerupted teeth. Through this method, the lesions were removed, with patient cooperation, and the cyst-associated teeth erupted spontaneously.

• Restorative Dentistry and Endodontics
• /
• v.27 no.4
• /
• pp.421-431
• /
• 2002

C-shaped canal configuration is very difficult to treat because that clues about preoperative canal anatomy cannot be ascertained from clinical crown morphology and limited information can be derived from radiographic examination. This study was done to get more informations about the root and canal configuration of C-shape root by 3-dimensionally reconstructing for the purpose of enhancing success rate of endodontic treatment. 30 mandibular molars with C-shaped root were selected. Six photo images from occlusal, apical, mesial, distal, buccal, lingual directions and radiographic view were taken as preoperative ones to compare them with 3-D image. After crown reduction to the level of 1-2mm over pulpal floor was performed, teeth were stored in 5.25% sodium hypochlorite solution for the removal of pulp tissue and debris. They were cleaned under running water, allowed to bench dry and embedded in a self-curing resin. This resin block was serially ground with a microtome (Accutom-50, Struers, Denmark) and the image of each level was recorded by digital camera (FinePix S1-pro, Fuji Co., Japan). The thickness of each section was 0.25mm. Photographs of serial sections through all root canal were digitized using Adobe Photoshop 5.0 and then minimum thickness of open and closed sites were measured (open site is the surface containing occluso-apical groove closed site is oppsite). After dizitization using 3-D Doctor (Able software Corp, USA). 3D reconstruction of the outer surface of tooth and the inner surface of pulp space was made. Canal classsification of C-shaped roots was performed from this 3-D reconstructed image. The results were as follows : 1. Most C-shape rooted teeth showed lingual groove (28/30). 2 According to Vertuccis' calssification, type I, II, III, IV, VII were observed. but also new canal types suck as 2-3-2, 1-2-3-2. 2-3-2-1, 2-3-2-3 were shown. 3 There was little difference in minimum thickness on coronal and apical portions, but open site were thinner than closed site on mid portion. Conclusively, 3D reconstruction method could make the exact configurations of C-shape root possible to be visualized and analyzed from multi-directions. Data from minimum thickness recommend cleaning and shaping be more carefully done on dangerous mid portion.

• Journal of Periodontal and Implant Science
• /
• v.29 no.3
• /
• pp.469-484
• /
• 1999

The purpose of this study was to evaluate new bone formation following guided bone regeneration by resorbable and nonresorbable membrane. Six adult mongrel dogs were used. The first, second, third, fourth premolars in the mandible of each dog were extracted. Two months after tooth extraction, a buccal dehiscence defect was surgically created on each edentulous area. The experimental sites were divided into three groups according to the treatment modalities ; Group I-a: surgical treatment only ; Group I -b: allogenic decalcified freezed dried bone grafting ; Group II-a : e- PTFE membrane placement only ; Group II-b : allogenic decalcified freezed dried bone grafting and e-PTFE membrane placement ; Group III-a : Vicryl(R) mesh placement only ; Group III-b : allogenic decalcified freezed dried bone grafting and Vicryl(R) mesh placement . The animals were sacrificed at 8 weeks after operation and the specimens were prepared for histologic and histometric examination. The results were as follows : Clinically, all defect sites were healed without exposure of barrier membrane after the eight weeks. In Group I-a, dense connective tissues were impinged in the bony defect area. Well vascularized and fibrous bone marrow indicated that bone formation was still taking place was found. In Group I-b, in areas closer to the periphery, lamellation of the newly formed bone would found. In Group II-a, beneath the e-PTFE membrane a dense layer of connective tissue covering the most external portions of the regenerated tissue was seen. The new bone surfaces were lined with osteoid and osteoblast. In Group II-b, a dense layer of connective tissue covering the most external portions of the regenerated tissue was observed beneath the e-PTFE membrane. A notable amount of alveolar ridge regeneration was seen with new rigdes with well-contoured form. In Group III-a, the new bone surface were lined with osteoid and osteoblast, indicating active bone formation. A clear demarcation could not be noted between the host bone and new bone. In Group III-b, a notable amount of alveolar ridge regeneration was seen with new ridges assuming wellcontoured form. In areas closer to the periphery, lamellation of the newly formed bone would found. As histometric examination, the amount of bone formation was gained from $12.8mm^2$ to $26.3mm^2$. It was significantly greater in group II-b and group III-b compared to other groups(p<0.05) . These results suggest that Vicryl(R) mesh after DFDB grafting used in guided bone regeneration could create and sustain sufficient space for new bone formation.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.26 no.3
• /
• pp.486-491
• /
• 1999

Hypoparathyroidism has abnormally decreased secretion of parathyroid hormon which responds to the blood calcium level. Wherease, Pseudohypoparathyroidism has normal activity of thyroid hormon, but end-organs, such as urinary tract and osteoclast, do not respond to parathyroid hormon. The cause of this disease is due to the mutation of Guanine stimulating(Gs) protein regulating Gs gene, which is the receptor to this hormon. Pseudohypoparathyroidism is usually noted before 20 years old on average of 8-9 years old. The clinical features of this disease includes delayed growth and development, round face, obesity, soft tissue calcification, ectopic ossification, shortening of metacarpals and metatarsals by epiphyseal closure in advance of age. The mutation of Gs gene which are found in brain, endocrine organs, and chondrocytes is the cause of those features. Reaction to Glucagon, gonadal hormon, and thyroid stimulating hormon is not expected in both cases. The common dental manifestations include enamel hypoplasia, delayed eruption, agenesis of tooth, hypodontia, dysplastic short roots, widened pulpal space, microdontia, intrapulpal calcification, and malocclusion are also often reported. This case which is diagnosed to Pseudohypoparathyroidism showed short and under-developed root of permanent troth, delayed eruption, and non-eruption of premolars and molars. And morphogenesis imperfecta of first and second premolars were also found.

• The korean journal of orthodontics
• /
• v.28 no.1 s.66
• /
• pp.61-74
• /
• 1998

The Purpose of this study was to investigate the stress distribution and tooth displacement at the initial phase produced by 5 types of molar uprighting springs using finite element method. The three dimensional finite element model of lower dentition, bone and springs was composed of 5083 elements and 2071 nodes. The results were as follows: 1. In case of helical spring and root spring, intrusion of lower canine and first premolar were observed md distal tipping, translation and extrusion of lower second molar were observed. 2. In case of T-loop, modified T-loop and box loop, intrusion and distal translation of lower second premolar were observed, and the largest crown distal tipping and translation of lower second molar were observed in T-loop and the smallest were observed in box loop. 3. In case of T-loop with cinch-bact crown distal tipping and translation of lower second molar were decreased, but extrusion was also decreased. 4. With increase of activation in T-loop, mesial translation and won distal tipping of lower second molar were increased and edentulous space was closing, but distal translation of second premolar was also increased. 5. With increase of tip-back bend in T--loop, distal tipping and translation of lower second molar were increased, but extrusion was also increased more largely.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.41
• /
• pp.4.1-4.10
• /
• 2019

Background: The mandibular third molar (M3) is typically the last permanent tooth to erupt because of insufficient space and thick soft tissues covering its surface. Problems such as alveolar bone loss, development of a periodontal pocket, exposure of cementum, gingival recession, and dental caries can be found in the adjacent second molars (M2) following M3 extraction. The specific aims of the study were to assess the amount and rate of bone regeneration on the distal surface of M2 and to evaluate the aspects of bone regeneration in terms of varying degree of impaction. Methods: Four series of panoramic radiographic images were obtained from the selected cases, including images from the first visit, immediately after extraction, 6 weeks, and 6 months after extraction. ImageJ software^® (NIH, USA) was used to measure linear distance from the region of interest to the distal root of the adjacent M2. Radiographic infrabony defect (RID) values were calculated from the measured radiographic bone height and cementoenamel junction with distortion compensation. Repeated measures of analysis of variance and one-way analysis of variance were conducted to analyze the statistical significant difference between RID and time, and a Spearman correlation test was conducted to assess the relationship between Pederson's difficulty index (DI) and RID. Results: A large RID (> 6 mm) can be reduced gradually and consistently over time. More than half of the samples recovered nearly to their normal healthy condition (RID ≤ 3 mm) by the 6-month follow-up. DI affected the first 6 weeks of post-extraction period and only showed a significant positive correlation with respect to the difference between baseline and final RID. Conclusions: Additional treatments on M2 for a minimum of 6 months after an M3 extraction could be recommended. Although DI may affect bone regeneration during the early healing period, further study is required to elucidate any possible factors associated with the healing process. The DI does not cause any long-term adverse effects on bone regeneration after surgical extraction.

• The Journal of Korean Academy of Prosthodontics
• /
• v.38 no.2
• /
• pp.147-159
• /
• 2000

The purpose of this study was the evaluation of spectral transmission of the commercial three shade guides and the relationship of hue, value, and chroma according to the transmission rate. The spectral transmittance of three shade guides - Vita Lumin Shade Guide, Vintage and Unibond Shade Guide, and Vitapan 3D-Master Shade Guide - were measured. For direct transmission measurements, each shade tabs were placed at the entrance port of the 1mm diameter intergrating sphere. The intensity of the light source passing through the shade tabs to the right angle was continuously recorded for wavelength from 400 to 700 nm. A transmission spectrum and digital data were obtained for each measurement and they were evaluated using Microcal Origin program. The obtained results of this study were as follows : 1. In Vita Lumin Shade Guide, sum of the transmission rate of the shade tabs at the wavelength 400-700nm was decreased in agreement with the arrangement order at each A, B, C, D group, except D4 shade tab. However, there were no relationships between the transmission rate of the shade tabs and the value-oriented. 2. In Vintage and Unibond Shade Guide, sum of the total transmission rate of the shade tabs was decreased in agreement with the arrangement order at each A, B, C, B group. When all shade tabs arranged in value-oriented, transmission rate was accord with the order, except D4 shade tab. 3. When shade tabs of the Vitapan 3D-Master Shade Guide have the same value and hue, sum of their total transmission rate decreased in accordance with the chroma-oriented. When the shade tabs have the same value and chroma, there were no differences from the order of the transmission rate to the various hue type. However, in the 'R' tabs of reddish hue type, the transmission rate increased at the long wavelength range area. In conclusion, we need the quantitative analyzing instruments in transmission determination. Vitapan 3D-Master Shade Guide covers the tooth color space taking into account the parameters of the systematic value, chroma, hue oriented, and the transmission rate relatively accorded with that sequence.