• The Journal of Korean Academy of Prosthodontics
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• v.33 no.3
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• pp.550-568
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• 1995

The purpose of this study was to observe the effects of early functional on bone formation around titanium plsama sprayed IMZ implants. 15 IMZ implants were inserted on the mandibular premolar areaa in 5 mondgrel dogs. The inplants were divided into 4 groups according to it’s loading schedule : Temporary abutments were connected for functional loading 6weeks, 9weeks, and 12weeks after implants installation in group I, II, and III, respectively. Abutments were not connected in the control group. After polyfluorochrome sequential labeling, all animals were sacrificed and bone sections includig implants and the 1st. molar were removed and processed for histologic evaluation. From light and fluorescence microscopic evaluation as well as histomorphometric and EPMA analysis, following results were obtained : 1. Light microscopically, the osteoid tissues were observed much in the compact bone of unloaded group, and cancellous bone formation observed more in early loaded group. 2. Calcification and remodeling of bone took place faster in loaded group, especially in 6 weeks group. 3. Moderate to severe marginal bone resorption was observed in 6 weeks group, mainly on buccal crest. 4. There was no difference in the percentages of bone-to-metal contact among the experimental groups. 5. In quantitative analysis using EPMA, there was no difference in the content of calcium and phosphorus among the experimental groups, regardless of distance.

• Journal of Periodontal and Implant Science
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• v.38 no.1
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• pp.103-108
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• 2008

Purpose: Studies reported controversial results about prognosis of root resection with 0%-38% failure rate. The purpose of this study is to consider clinical efficacy of root resection. Materials and Methods: This study reported three cases of root resection which were performed on different sites. In first case, lower right first molar showed pus discharge and 7 mm of probing pocket depth. It was diagnosed as fracture of mesial root. Hemisection of mesial root was performed. In second case, upper right first molar showed severe bone loss on disto-buccal root and 7 mm of probing pocket. Resection of disto-buccal root was performed In third case, lower left second molar showed severe bone loss on distal root including apex and 15mm of probing pocket depth. Hemisection of distal root was performed. Result: In these three cases of root resection, compromised molars were treated successfully and conserved. Conclusion: Root resection is a successful procedure treating compromised multi-rooted teeth and conserving teeth when proper case selection is performed.

• The korean journal of orthodontics
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• v.48 no.2
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• pp.81-89
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• 2018

Objective: The aim of this study was to evaluate the stress distribution and displacement of various craniofacial structures after nonsurgical rapid palatal expansion (RPE) with conventional (C-RPE), bone-borne (B-RPE), and miniscrew-assisted (MARPE) expanders for young adults using three-dimensional finite element analysis (3D FEA). Methods: Conventional, bone-borne, and miniscrew-assisted palatal expanders were designed to simulate expansion in a 3D FE model created from a 20-year-old human dry skull. Stress distribution and the displacement pattern for each circumaxillary suture and anchor tooth were calculated. Results: The results showed that C-RPE induced the greatest stress along the frontal process of the maxilla and around the anchor teeth, followed by the suture area, whereas B-RPE generated the greatest stress around the miniscrew, although the area was limited within the suture. Compared with the other appliances, MARPE caused relatively even stress distribution, decreased the stress on the buccal plate of the anchor teeth, and reduced tipping of the anchor teeth. Conclusions: The findings of this study suggest that the incorporation of miniscrews in RPE devices may contribute to force delivery to the sutures and a decrease in excessive stress on the buccal plate. Thus, MARPE may serve as an effective modality for the nonsurgical treatment of transverse maxillary deficiency in young adults.

• Journal of Periodontal and Implant Science
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• v.54 no.2
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• pp.108-121
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• 2024

Purpose: The aim of this study was to compare changes in soft and hard tissue and the histologic composition following early implant placement in sites with alveolar ridge preservation or spontaneous healing (SH), as well as implant performance up to 1 year after crown insertion. Methods: Thirty-five patients with either intact buccal bone plates or dehiscence of up to 50% following single-tooth extraction of incisors, canines, or premolars were included in the study. They were randomly assigned to undergo one of three procedures: deproteinized bovine bone mineral with 10% collagen (DBBM-C) covered by a collagen matrix (DBBM-C/CM), DBBM-C alone, or SH. At 8 weeks, implant placement was carried out, and cone-beam computed tomography scans and impressions were obtained for profilometric analysis. Patients were followed up after the final crown insertion and again at 1 year post-procedure. Results: Within the first 8 weeks following tooth extraction, the median height of the buccal soft tissue contour changed by -2.11 mm for the DBBM-C/CM group, -1.62 mm for the DBBM-C group, and -1.93 mm for the SH group. The corresponding height of the buccal mineralized tissue changed by -0.27 mm for the DBBM-C/CM group, -2.73 mm for the DBBM-C group, and -1.48 mm for the SH group. The median contour changes between crown insertion and 1 year were -0.19 mm in the DBBM-C/CM group, -0.09 mm in the DBBM-C group, and -0.29 mm in the SH group. Conclusions: Major vertical and horizontal ridge contour changes occurred, irrespective of the treatment modality, up to 8 weeks following tooth extraction. The DBBM-C/CM preserved more mineralized tissue throughout this period, despite a substantial reduction in the overall contour. All 3 protocols led to stable tissues for up to 1 year.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.38 no.2
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• pp.116-120
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• 2012

The buccal fat pad is specialized fat tissue located anterior to the masseter muscle and deep to the buccinator muscle. Possessing a central body and four processes it provides separation allowing gliding motion between muscles, protects the neurovascular bundles from injuries, and maintains facial convexity. Because of its many advantageous functions, the use of the buccal fat pad during oral and maxillofacial procedures is promoted for the reconstruction of defects secondary to tumor resection, and those defects resulting from oroantral fistula caused by dento-alveolar surgery or trauma. We used the pedicled buccal fat pad in the reconstruction of intraoral defects such as oroantral fistula, maxillary posterior bone loss, or defects resulting from tumor resection. Epithelization of the fat tissue began 1 week after the surgery and demonstrated stable healing without complications over a long-term period. Thus, we highly recommend the use of this procedure.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.46 no.4
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• pp.250-257
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• 2020

Objectives: Palatal infiltration is the most painful and uncomfortable anesthesia technique for maxillary impacted third molar surgery (MITMS). This approach could cause patients distress and aversion to dental treatment. The aim of this study was to evaluate the anesthetic efficacy of a buccal infiltration injection without a palatal injection in MITMS. Materials and Methods: This prospective research study was a crossover split mouth-randomized controlled trial. Twenty-eight healthy symmetrical bilateral MITMS patients (mean age, 23 years) were randomly assigned to two groups. Buccal infiltration injections without palatal injections were designated as the study group and the buccal with palatal infiltration cases were the control group, using 4% articaine and 1:100,000 epinephrine. The operation started after 10 minutes of infiltration. Pain assessment was done using a visual analogue scale and a numeric rating scale after each injection and extraction procedure. Similarly, the success rate, hemodynamic parameters, and additional requested local anesthetic were assessed. Results: The results showed that the pain associated with local anesthetic injections between both groups were significantly different. However, the success rates between the groups were not significantly different. Postoperative pain was not significant between both groups and a few patients requested an additional local anesthetic, but the results were not statistically significant. For hemodynamic parameters, there was a significant difference in systolic pressure during incision, bone removal, and tooth elevation. In comparison, during the incision stage there was a significant difference in diastolic pressure; however, other steps in the intervention were not significantly different between groups. Conclusion: We concluded that buccal infiltration injection without palatal injection can be an alternative technique instead of the conventional injection for MITMS.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.17 no.1
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• pp.233-248
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• 1987

The author studied the effect of periapical bone loss on radiographic interpretation by using a dry adult human mandible. Artificial bony lesions were created at the apices of two mandibular second molars and four mandibular bicuspids. The jaw was stabilized and various artificial lesions were radiographed under ideal circumstances. Radiographic pictures were recorded and compared with the size of the actual lesions. The obtained results were as follows: 1. The size of actual lesions were always larger than their radiographic pictures. 2. The size of actual lesion had a greater discrepancy in the molar area where the cortical plates were havier, but the lesions in the bicuspid areas were only slightely larger than their radiographic pictures, and in these areas the cortical plates were quite thin. 3 Periapical lesions located in cancellous bone did not appear on a radiograph, regardless of the size of the created lesion, but when the junctional bone was involved or the cortical plate was perforated, the definite bone destructive change was observed on the roentenogram. 4. Removal of the entire buccal or lingual plate did not affect the trabecular pattern of bone on the roentgenogram. 5. When the cancellous bone and junctional bone were removed simultaneously, altered trabecular patterns were observed on the roentgenogram.

• The korean journal of orthodontics
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• v.31 no.6 s.89
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• pp.559-566
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• 2001

This study was undertaken to demonstrate the forces in the mandibular alveolar bone generated by activation of the mandibular posterior crossbite appliance in the treatment of buccal crossbite caused by lingual eruption of mandibular second molar. A three-dimensional photoelastic model was fabricated using a photoelastic material (PL-3) to simulate alveolar bone. We observed the model from the anterior to the posterior view in a circular polariscope and recorded photogtaphically before and after activation of the mandibular posterior crossbite appliance. The following results were obtained : 1. When the traction force was applied on the buccal surface of the mandibular second molar, stress was concentrated at the lingual alveolar crest and root apex area. The axis of rotation also was at the middle third of the buccal toot surface and the root apex, so that uncontrolled tipping and a buccal traction force for the mandibular second molar were developed. 2. When the traction force was applied on the lingual surface of the mandibular second molar more stress was observed as opposed to those situations in which the force application was on the buccal surface. In addition, stress intensity was increased below the loot areas and the axis of rotation of the mandibular second molar was lost. In result, controlled tipping and intrusive tooth movements were developed. 3. When the traction forte was applied on either buccal or lingual surface of the second molar, the color patterns of the anchorage unit were similar to the initial color pattern of that before the force application. So we can use the lingual arch for effective anchorage in correcting the posterior buccal crossbite. As in above mentioned results, we must avoid the rotation and uncontrolled tipping, creating occlusal interference of the malpositioned mandibular second molar when correcting posterior buccal crossbite. For this purpose, we recommend the lingual traction force on the second molar as opposed to the buccal traction.

• The korean journal of orthodontics
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• v.25 no.1 s.48
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• pp.101-110
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• 1995

The purpose of this study was to observe the tissue response to the orthodontic force applied immediately after buccal horizontal subapical osteotomy of maxilla. Five mongrel cats weighing about 2.5 Kg were used for this experiment. The left upper canine and premolar of each cat served as a experimental side and the right ones as a control side. On the experimental side, a 100gm orthodontic force was applied between the upper canine and premolar immediately after the osteotomy. On the control side, the same orthodontic force was applied without the osteotomy. After 7days, the experimental animals were sacrificed. The results were as follows: 1. In the pressure zones of the experimental group, significant increase of osteoclasts and direct resolution along the alveolar bone surface was observed as compared with those of the control group. 2. In the pressure 2ones of the experimental group, a less extensive hyalinized zone was observed than those of the control group. 3. In the pressure zones of both group, no root resorption was found. 4. Tn the tension zones of the experimental group, new bone deposition increased along the alveolar bone surface as compared with those of the control group. In conclusion, the results suggest the possibility that early orthodontic treatment after orthognathic surgery may have some benefits if the stability of the repositioned segment at surgery is secured.

• Journal of Periodontal and Implant Science
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• v.49 no.3
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• pp.171-184
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• 2019

Purpose: To evaluate the effects of intra-alveolar socket grafting, subepithelial connective tissue grafts, and individualized abutments on peri-implant hard and soft tissue outcomes following immediate implant placement. Methods: This randomized experimental study employed 5 mongrel dogs, with 4 sites per dog (total of 20 sites). The mesial roots of P3 and P4 were extracted in each hemimandible and immediate dental implants were placed. Each site was randomly assigned to 1 of 4 different treatment groups: standardized healing abutment (control group), alloplastic bone substitute material (BSS) + standardized healing abutment (SA group), BSS + individualized healing abutment (IA group), and BSS + individualized healing abutment + a subepithelial connective tissue graft (IAG group). Clinical, histological, and profilometric analyses were performed. The intergroup differences were calculated using the Bonferroni test, setting statistical significance at P<0.05. Results: Clinically, the control and SA groups demonstrated a coronal shift in the buccal height of the mucosa ($0.88{\pm}0.48mm$ and $0.37{\pm}1.1mm$, respectively). The IA and IAG groups exhibited an apical shift of the mucosa ($-0.7{\pm}1.15mm$ and $-1.1{\pm}0.96mm$, respectively). Histologically, the SA and control groups demonstrated marginal mucosa heights of $4.1{\pm}0.28mm$ and $4.0{\pm}0.53mm$ relative to the implant shoulder, respectively. The IA and IAG groups, in contrast, only showed a height of 2.6mm. In addition, the height of the mucosa in relation to the most coronal buccal bone crest or bone substitute particles was not significantly different among the groups. Volumetrically, the IA group ($-0.73{\pm}0.46mm$) lost less volume on the buccal side than the control ($-0.93{\pm}0.44mm$), SA ($-0.97{\pm}0.73mm$), and IAG ($-0.88{\pm}0.45mm$) groups. Conclusions: The control group demonstrated the most favorable change of height of the margo mucosae and the largest dimensions of the peri-implant soft tissues. However, the addition of a bone substitute material and an individualized healing abutment resulted in slightly better preservation of the peri-implant soft tissue contour.