• Journal of Dental Rehabilitation and Applied Science
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• v.31 no.3
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• pp.169-177
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• 2015

Purpose: The objects of this study were to examine the thickness of labial plate of anterior maxillary teeth and the gingival biotype in Koreans and to evaluate whether there is a correlation between the gingival biotype and the thickness of labial plate. Materials and Methods: This study was performed on 335 teeth of 57 subjects at the Pusan National University Dental Hospital. Cone Beam Computed Tomography (CBCT) was used to measure the thickness of labial plate at 4 mm, 6 mm, 8 mm from the cementoenamel junction and the gingival biotype was determined by the visibility of periodontal probe. Results: Thin facial bone less than 1 mm was observed in 87% at 4 mm, 88% at 6 mm and 90% at 8 mm. In 21% of total objects, thin gingival biotype was observed. There is no correlation between the thickness of labial plate and gingival biotype. Conclusion: Additional thorough radiographic examination such as CBCT was mandatory for aesthetic dental implant in the anterior dentition besides clinical oral examination.

• The korean journal of orthodontics
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• v.31 no.1 s.84
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• pp.97-105
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• 2001

In many cases of orthodontic treatment the upper anterior teeth are retracted. Periodontal problems may arise during incisor retraction, if the amount of tooth movement and the amount of remodeling in the anterior cortical bone are not the same. Therefore in this study, to find out the relationship between the amount of tooth movement and the amount of bone remodeling during retraction of the upper anterior teeth, lateral cephalograms of 56 female patients over 18-year-old were taken before and after treatment. Among the 56 patients, two groups were divided according to the type of root movement during retraction. 26 patients mainly moved by tipping and 30 by bodily movement. The cephalograms taken before and after treatment were superimposed upon the true horizontal plane. In the Tip-Group, the horizontal bone remodeling/tooth movement ratio was 1:1.63, and in the Torque-Group it was 1:1.66. Because the amount of tooth movement and the amount of bone remodeling were not the same in both groups, in the Tip-Group the root apex moved away from the palatal cortical plate and closer to the labial cortical plate, whereas in the Torque-Group the root moved away from the labial cortical plate and closet to the palatal cortical plate. Therefore, there are limitations in the amount of incisor retraction in patients with a very thin anterior cortical plate in the maxilla, and in patients with severe skeletal discrepancies orthognathic surgery should be considered and when orthodontic camouflage treatment is the only possible method, the orthodontist must be aware of the limitations of treatment.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.29 no.5
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• pp.444-450
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• 2007

In general, labiolingual or buccolingual widths of residual alveolar bone are insufficient in edentulous area, because of alveolar resorption. Horizontal augmentation is bone graft procedure with a view to reinforcing horizontally insufficient bone quantity for installation of implants. The standard method is taking appropriate amount of block bone from intraoral or extraoral autogenous bone, and solid fixation with screws or mini-plate on labial or buccal side of residual alveolar bone. The purpose of this study is to discuss clinical usefulness of horizontal augmentation with autogenous block bone by observation and analysis of course of 41 implants installed to 12 patients by horizontal augmentation in Seoul National University Bundang Hospital from July, 2002 to December, 2005. The mean age of patients is 52.7, from 19 to 70, and the number of men and women is each 2 and 10. Block bone was taken from symphysis, body, ramus of mandible or iliac bone. And 6 types of implants were installed simultaneously or not, the diameters of implants are from 3.3 to 5.5mm, the lengths are from 8 to 15mm. The operator added artificial bone grafting material and optionally covered with membrane. The mean periods of observation after operation and final prosthetics were 28.6 and 17.0 months. As a result, 40 among 41 implants survived, the survival rate was 97.6%. Average 0.9mm crestal resorption was observed at final point of time by periapical view of each patients. Major complication related to the procedure was numbness in 7 patients.

• Journal of Dental Rehabilitation and Applied Science
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• v.28 no.3
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• pp.277-290
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• 2012

Dental implants are universal restorative method on edentulous site in oral cavity and generally recognized by patients as well as clinicians. Rapid bone resorption of labial portion of maxillary anterior area is performed due to dental trauma, chronic periodontitis, and so on. Accordingly, Implants on maxillary anterior alveolar ridge with narrow labiopalatal width would lead to bony defects of dehiscence or fenestration. In this case, guided bone regeneration procedure is used to augment maxillary anterior alveolar ridge. It can have mechanical and biological advantages to mix tissue adhesive with bone graft materials in guided bone regeneration procedure. In these cases, when the dehiscence or fenestration defects was occurred by dental implants on maxillary anterior alveolar ridge with narrow labiopalatal width, guided bone regeneration procedures were performed with various combination of particle bone graft materials(allograft, xenograft, and alloplast) mixed with fibrin glue, excepting autogerous bone. We reported that all of 4 cases showed favorable alveolar ridge augmentations.

• The Journal of Korean Academy of Prosthodontics
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• v.33 no.2
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• pp.177-197
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• 1995

The endodontically treated tooth is generally restored with post & core, owing to the brittleness and the loss of large amount of tooth structure. Although there have been lots of studies about the endodontically treated teeth, the three-dimensional quantitative studies about the strees distribution of them are in rare cases. In this study, it was assumed that the coronal portion of the upper incisou had severely damaged. After the root canal therapy it was post cored, and restored with PFM crown, for this experiment nine types of model were constructed : 1); long, 2); medium, 3); short gold post for the roots supported with a narmal alveolar bone, 4); long, 5); medium, 6); short gold post for the roots supported with an alveolar bone resorbed to its 1/3 of root length, 7); long, 8); medium, 9); short base metal post for the roots supported with an alveolar bone resorbed to its 1/3 of root length. Force was applied from two directions. One was functional maximum bite force(300N) applied to the spot just lingual to the incisal edge with the angle of 45 degrees to the long axis of the tooth, and the other one was horizontal force(300N) applied to the labial surface. The results analyzed with three-dimensional finite element method were as follows : 1. Stress was concentrated on the middle portion of the labial side dentin of the root and the lingual portion of the apical dentin of the root. Stress in the post showed maximum value at 2 mm above the post apex. 2. In case of the long post and base metal post, strees was concentrated on the apex of the root and the post. 3. In case of the longer post, the displacement on the post-cement interface was lessened. The gold post was more displaceable than the base metal post. 4. In case of the alveolar bone resorption, stress concentrated on the root and the post and displacement on the post-cement interface were increased.

• Journal of the korean academy of Pediatric Dentistry
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• v.50 no.2
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• pp.142-154
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• 2023

The canine tooth is important both functionally and aesthetically, being positioned between the anterior and posterior teeth. The upper canine has the longest eruption path, forming in the deepest part of the maxillary bone and often experiencing eruption disorders, leading to significant aesthetic and functional issues. Early detection and management of canine impaction are crucial in pediatric dentistry, which focuses on tooth growth and eruption. The prevalence of maxillary canine impaction ranges from 1.1% to 3.0%. In Western populations, palatal impaction is twice as common as labial impaction, while some Korean studies report more labial impaction. Maxillary canine impaction occurs more frequently in women and is associated with various factors such as structural obstacles, pathological conditions in surrounding tissues, developmental abnormalities, and genetic factors. Labial displaced canines are linked to narrow maxillary intercanine width, total dental crowding, and skeletal Class III malocclusion. Maxillary palatal displaced canine impaction is more prevalent in patients with familial agenesis of lateral incisors or conical supernumerary lateral incisors. Understanding these factors aids in early diagnosis and appropriate intervention for canine tooth impaction, ensuring optimal oral health and aesthetics.

• Journal of the korean academy of Pediatric Dentistry
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• v.21 no.2
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• pp.577-585
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• 1994

The Twin Blocks technique was developed by Dr. William Clark of Scotland during the early 1980's. Twin Blocks are an uncomplicated system that incorporates the use of upper and lower bite blocks. These blocks reposition the mandible and redirect occlusal forces to achieve rapid correction of malocclusions. They are also comfortable and the patients wear them full-time-inducing eating time. Occlusal forces transmitted through the dentition provide a constant proprioceptive stimulus to influence the rate of growth and the trabecular structure of the supporting bone. The features of Twin Blocks mean easier and quicker treatment. The occlusal inclined plane is the fundamental functional mechanism of the natural dentition. Twin blocks are bite blocks that effectively modify the occlusal inclined plane to induce favorably directed occlusal forces by causing a functional mandibular displacement. Upper and lower bite blocks interlock at a $45^{\circ}$ angle and are designed for full-time wear to take advantage of all functional forces applied to the dentition including the forces of mastication. The patients who were treated with modified Twin Blocks, and following results were observed: 1. Large overjet and deep overbite were corrected. 2. Class II molar relationship was changed into Class I. 3. Labial inclination of upper incisors was corrected by adjustment of labial bow of upper bite block. 4. The profiles of two patients were improved by anterior displacement of mandible.

• Restorative Dentistry and Endodontics
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• v.19 no.2
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• pp.549-567
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• 1994

Restoration of severly damaged teeth after endodontic treatment had been an interest to many dentists, and it is a fact that there have been lots of studies about it. In these days, although we have used Para-Post, pins, threaded steel post, cast gold post and core, and so on, as a method of restoration frequently, it has been in controversy with the influence of them on the teeth and surrounding periodontal tissue. In this study, we assume that the crown of the upper incisor have severly damaged, so, after the root canal therapy, 4 types of restoration had been carried out; 1) coronal-radicular amalgam restoration, 2) after setting up the Para-Post, restore with composite resin core only, 3) after setting up the Para-Post; restore with amalgam core, then cover with the PPM crown 4) after setting up the Para-Post, restore with composite core, then cover with the PPM crown. After restoration, in order to observe the concentration of stress at internal portion of the teeth and the sourrounding periodontal tissue, developing a 2-dimensional finite element model of labiopalatal section, then loading forces from 3 direction - direction of 45 degrees from lingual side near the incisal edge, horizontal direction from labial height of contour, vertical direction at the incisal edge-were applied. The analyzed results were as follows: 1. Stress of the normal central incisor was concentrated on the dentin aroundpulp chamber, labiocervical portion of a tooth and root apex, but with the alveolar bone, in the case of load from the direction of 45 degrees from lingual side near the incisal edge showed remarkable concentration of stress: 2. Coronal-radicular amalgam technique -showed less concentration of stress on the root and surrounding periodontal tissue than the restoration with the Para-Post. 3. The von Mises equivalent stress on the Para-Post showed maximum value at root-core junction rather than both ends and model with PPM restoration with amalgam core showed the least concentration of stress. Only the force from horizontal direction showed large shear stress on internal portion of the root, root apex and alveolar bone. 4. PPM crown with composite core rarely showed the concentration of stress on root and periodontal tissue. 5. As for alveolar bone, remarkable shear stress was concentrated on labial and palatal side by horizontal load.

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

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.4
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• pp.330-333
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• 2009

Alveolar bone resorption after extraction impairs the necessary bone volume and complicates the case for implant surgery and aesthetic implant prosthesis. Immediate implant surgery after extraction decreases the number of surgical procedures and the duration of treatment, while allowing minimum alveolar bone resorption and preserving the residual bone volume. Although immediate implant holds many advantages such as preservation of hard and soft tissue around the extraction socket, greater implant survival rate and higher patient satisfaction, various complications and high failure rate are discouraging factors for the clinicians. In this case report, severe alveolar bone resorption with soft tissue changes were predicted after the extraction of prolonged retained deciduous incisors and impacted maxillary canines and thus decided on immediate implant procedure. Immediate implant surgery after extraction was carried out with minimal bone reduction and tapered wide-neck implant to establish initial stability. Simultaneous bone graft was done by filling the defect area with iliac cancellous bone with additional onlay-type bone graft and absorbable membrane on the labial bone for upper lip support. A stable and esthetic result was obtained with shortened treatment period.