• Journal of Korean Dental Science
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• v.17 no.2
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• pp.53-63
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• 2024

Purpose: To investigate the effects of simultaneous soft and hard tissue augmentation and the addition of polydeoxyribonucleotide (PDRN) on regenerative outcomes. Materials and Methods: In five mongrel dogs, chronic ridge defects were established in both mandibles. Six implants were placed in the mandible, producing buccal dehiscence defects. The implants were randomly allocated to one of the following groups: 1) control: no treatment; 2) GBR: guided bone regeneration (GBR) only; 3) GBR/PDRN: GBR+PDRN application to bone substitute particles; 4) GBR/CTG: GBR+connective tissue grafting (CTG); 5) GBR/VCMX: GBR+soft tissue augmentation using volume stable collagen matrix (VCMX); and 6) group GBR/VCMX/PDRN: GBR+VCMX soaked with PDRN. The healing abutments were connected to the implants to provide additional room for tissue regeneration. Submerged healing was achieved. The animals were euthanized after four months. Histological and histomorphometric analyses were then performed. Results: Healing abutments were gradually exposed during the healing period. Histologically, minimal new bone formation was observed in the dehiscence defects. No specific differences were found between the groups regarding collagen fiber orientation and density in the augmented area. No traces of CTG or VCMX were detected. Histomorphometrically, the mean tissue thickness was greater in the control group than in the other groups above the implant shoulder (IS). Below the IS level, the CTG and PDRN groups exhibited more favorable tissue thickness than the other groups. Conclusion: Failure of submerged healing after tissue augmentation deteriorated the tissue contour. PDRN appears to have a positive effect on soft tissues.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.47 no.1
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• pp.34-39
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• 2021

Objectives: The purpose of the study was to assess the occurrence, location, and dimensions of the intraosseous vascular canal in the lateral wall of the maxillary antrum using cone-beam computed tomography (CBCT). Materials and Methods: In this retrospective study, we examined 400 CBCT scans from our archive of patients who had earlier reported to a dental teaching hospital in the United Arab Emirates. The prevalence, location, and dimensions of the lateral antral intraosseous canal (LAIC) in the maxillary antrum were evaluated by 2 examiners using standardised methods. A third examiner was consulted in cases of disagreement. Results: The prevalence of LAIC was 62.3% (249 maxillary antra) among the study population. The mean distance between the most inferior point of the alveolar bone and the inferior border of the LAIC in the posterior maxillary region was 19.83±3.12 mm. There was a significant difference (P=0.05) between the maxillary molar and premolar regions in mean distance from the most inferior point of the alveolar bone and the inferior border of the LAIC. There was no statistically significant difference in mean distance between the most inferior point of the alveolar bone and the inferior border of the LAIC between dentulous and edentulous areas (P=0.1). The G3-intrasinusal type canal less than 1mm in diameter was the most common type of LAIC. Conclusion: This study established the approximate location of the LAIC in a United Arab Emirates cohort, which will assist the oral surgeon in selecting the appropriate site for sinus lift procedures with reduced risk of surgical hemorrhage.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.39 no.6
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• pp.274-282
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• 2013

Objectives: The posterior maxillary region often provides a limited bone volume for dental implants. Maxillary sinus elevation via inserting a bone graft through a window opened in the lateral sinus wall has become the most common surgical procedure for increasing the alveolar bone height in place of dental implants in the posterior maxillary region. The purpose of this article is to assess the change of bone volume and the clinical effects of dental implant placement in sites with maxillary sinus floor elevation and autogenous bone graft through the lateral window approach. Materials and Methods: In this article, the analysis data were collected from 64 dental implants that were placed in 24 patients with 29 lacks of the bone volume posterior maxillary region from June 2004 to April 2011, at the Department of Oral and Maxillofacial Surgery, Inha University Hospital. Panoramic views were taken before the surgery, after the surgery, 6 months after the surgery, and at the time of the final follow-up. The influence of the factors on the grafted bone material resorption rate was evaluated according to the patient characteristics (age and gender), graft material, implant installation stage, implant size, implant placement region, local infection, surgical complication, and residual alveolar bone height. Results: The bone graft resorption rate of male patients at the final follow-up was significantly higher than the rate of female patients. The single autogenous bone-grafted site was significantly more resorbed than the autogenous bone combined with the Bio-Oss grafted site. The implant installation stage and residual alveolar height showed a significant correlation with the resorption rate of maxillary sinus bone graft material. The success rate and survival rate of the implant were 92.2% and 100%, respectively. Conclusion: Maxillary sinus elevation procedure with autogenous bone graft or autogenous bone in combination with Bio-Oss is a predictable treatment method for implant rehabilitation.

• The Journal of Korean Academy of Prosthodontics
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• v.56 no.4
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• pp.338-346
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• 2018

Crossed occlusion can be treated either by overdenture and telescopic denture or by placing an implant at the edentulous area to reestablish the support on the occlusion. If alveolar bony support is sufficient and an the environment where an implant is inserted is favorable to restoring the masticatory and aesthetic function of a patient, the implant-supported fixed prosthesis can provide more definitive occlusal support and more aid for other oral functions. In this case report, a patient with a severe residual alveolar bone resorption following the extraction of teeth and who had a crossed occlusion was treated with sinus bone graft and alveolar bone augmentation in order to place the implants at prosthetically position. The definitive restoration was made to reflect the patient's occlusal and aesthetic function using the CAD/CAM double scanning method. Finally, the treatment had the masticatory and aesthetic function adequately restored, which is reported here.

• The Journal of the Korean dental association
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• v.55 no.1
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• pp.30-41
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• 2017

Inadequate keratinized mucosa around dental implants can lead to more plaque accumulation, tissue inflammation, marginal recession and attachment loss. We evaluated the effects of free gingival and extracellular matrix membrane grafts performed to increase the insufficient width of keratinized tissue around dental implants in the posterior mandible. A 47-year-old female patient presented with discomfort due to swelling of the lower right second premolar area. Due to severe destruction of alveolar bone, the tooth was extracted. After 3 months, a guided bone regeneration (GBR) procedure was performed and then a dental implant was placed 6 months later. During the second-stage implant surgery, free gingival grafting was performed to increase the width of the keratinized tissue. After 12 months, a clinical evaluation was performed. A 64-year-old female patient had a missing tooth area of bilateral lower molar region with narrow zone of keratinized gingiva and horizontal alveolar bone loss. Simultaneous implant placement and GBR were performed. Five months after the first-stage implant surgery, a gingival augmentation procedure was performed with an extracellular matrix membrane graft to improve the width of the keratinized tissue in the second-stage implant surgery. After 12 months, a clinical evaluation was performed. In these two clinical cases, 12 months of follow-up, revealed that the increased width of the keratinized tissue and the deepened oral vestibule was well maintained. A patient showed a good oral hygiene status. In conclusion, increased width of keratinized tissue around dental implants could improve oral hygiene and could have positive effects on the long-term stability and survival rate of dental implants. When planning a keratinized tissue augmentation procedure, clinicians should consider patient-reported outcomes.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.23 no.4
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• pp.324-331
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• 2001

The present study was aimed to investigate the effects of latency period on alveolar ridge distraction using the intraoral distraction device. Nine adult mongrel dogs of either sex, weighing about 15kg, were used. They were divided into 3-day, 5-day, and 7-day groups according to the latency period. The left upper and lower premolars and first molars were extracted. Twelve weeks after the extraction, an osteotomy was performed and the distraction device was applied. After the latency period, the distraction was applied at a rate of 1.2mm for 8 days. The distraction device was left in place for 2 weeks to allow consolidation and was then removed. The animals were sacrified at 8 weeks after completion of distraction and were examined macroscopically, radiographically, and histologically. After completion of the distraction, the alveolar crest protruded prominently, showing the vertical augmentation of the alveolar bone. Soft tissues were broken down after the 6th day of distraction in 3-day latency group, and premature union occurred on the 7th day of distraction in the 7-day latency group. The average distance was $9.40{\pm}0.3mm$ in 3-day latency group, $9.35{\pm}0.1mm$ in 5-day latency group, and $8.85{\pm}0.1mm$ in 7-day latency group. In the radiograph taken at 8 weeks after distraction, there was slight bone resorption around the medial and distal edges of the alveolar bone segment, and a new bone deposition was observed in the neighboring alveolar crest area in all groups. Fibrous tissues were present in a part of the buccal cortical bone area of the distraction gap, and the woven and lamellar bones were observed in the distracted gap. There were bony bridges in the distraction gap in all animals examined. These results suggest that optimal time of latency period on alveolar ridge distraction using the intraoral distraction device is about 5 days in dogs, and about 7days in human beings.

• Journal of Korean Dental Science
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• v.17 no.2
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• pp.84-91
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• 2024

Achieving both esthetic and functional implant rehabilitation is crucial for the successful treatment of the anterior maxilla. Adequate peri-implant alveolar bone and soft tissue are essential for optimal rehabilitation of the esthetic area, and there is a direct association between the implant position and prosthetic outcomes. Immediate provisionalization may also be advantageous when combined with augmentation. This case report described the implant placement in a 25-year-old female patient who had lost her right maxillary lateral incisor (#12) due to trauma-induced avulsion. The treatment involved simultaneous grafting and collagenated, deproteinized bovine bone mineral, along with subepithelial connective tissue taken from the right maxillary tuberosity. A polyetheretherketone abutment and non-functional immediate provisionalization were performed by removing both the proximal and occlusal contacts on the composite resin crown. Clinical and radiographic evaluations revealed maintenance of stable ridge contour aspects for six months following surgical treatment. In summary, implant rehabilitation in the esthetic zone can be successful using simultaneous soft and hard tissue grafts. Moreover, soft tissue stabilization post-subepithelial connective tissue grafting can be achieved through early or immediate visualization, along with immediate implant placement.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.41 no.5
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• pp.284-289
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• 2015

In cases of severe alveolar bone atrophy in the posterior maxillary area, which has only a thin sinus floor, the autogenous tooth bone graft block (ABTB) was used to wrap the implant to enhance its primary stability and osseointegration in the sinus. These cases with four years of clinical follow-up demonstrate the applicability of the ABTB in maxillary sinus membrane elevation to improve the outcomes of implant placement.

• Journal of Periodontal and Implant Science
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• v.48 no.3
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• pp.174-181
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• 2018

Purpose: The aims of the present study were to quantitatively assess graft height changes after sinus lift procedures and to analyze the factors that influenced graft height changes, including the residual bone height before surgery, surgical approach, and tooth type. Methods: A total of 39 maxillary posterior implants placed during a simultaneous sinus lift procedure were evaluated. Panoramic radiographs of all patients were taken immediately after implant installation and at 3 months, 6 months, 1 year, 2 years, and 3 years. To analyze graft height changes over time, we measured the distance between the implant platform and the base of the grafted sinus floor at 3 locations. The radiographs were analyzed by a single examiner. Results: Graft height tended to decrease over time, and a statistically significant difference was observed at 2 years compared to baseline (P<0.05). There was no statistically significant difference in graft height change according to the surgical approach or tooth type. For residual bone height, a statistically significant difference in graft height change was found between those with 4-7 mm of residual bone height and those with ${\geq}7mm$ (P<0.05). Conclusions: Graft height after sinus lift procedures significantly decreased at 2 years compared to baseline after sinus augmentation. Further studies should be done with controlled variables, and prospective studies with 3-dimensional images are needed to clarify the factors that influence graft height changes.

• Journal of Periodontal and Implant Science
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• v.52 no.2
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• pp.170-180
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• 2022

Purpose: This study was conducted to assess the effect of hard and/or soft tissue grafting on immediate implants in a preclinical model. Methods: In 5 mongrel dogs, the distal roots of P2 and P3 were extracted from the maxilla (4 sites in each animal), and immediate implant placement was performed. Each site was randomly assigned to 1 of the following 4 groups: i) gap filling with guided bone regeneration (the GBR group), ii) subepithelial connective tissue grafting (the SCTG group), iii) GBR and SCTG (the GBR/SCTG group), and iv) no further treatment (control). Non-submerged healing was provided for 4 months. Histological and histomorphometric analyses were performed. Results: Peri-implant tissue height and thickness favored the SCTG group (height of periimplant mucosa: 1.14 mm; tissue thickness at the implant shoulder and ±1 mm from the shoulder: 1.14 mm, 0.78 mm, and 1.57 mm, respectively; median value) over the other groups. Bone grafting was not effective at the level of the implant shoulder and on the coronal level of the shoulder. In addition, simultaneous soft and hard tissue augmentation (the GBR/SCTG group) led to a less favorable tissue contour compared to GBR or SCTG alone (height of periimplant mucosa: 3.06 mm; thickness of peri-implant mucosa at the implant shoulder and ±1 mm from the shoulder: 0.72 mm, 0.3 mm, and 1.09 mm, respectively). Conclusion: SCTG tended to have positive effects on the thickness and height of the periimplant mucosa in immediate implant placement. However, simultaneous soft and hard tissue augmentation might not allow a satisfactory tissue contour in cases where the relationship between implant position and neighboring bone housing is unfavorable.