• The Journal of the Korean dental association
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• v.55 no.11
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• pp.756-765
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• 2017

Purpose: The purpose of this article is to evaluate a change o bone level on the sinus floor by a bone added osteotome sinus floor elevation (BAOSFE) technique, according to the amount of deproteinized bovine bone mineral (DBBM). And Changes in augmented bone height after BAOSFE procedure were also assessed for 6 months after the implant procedure. Materials and Methods: Forty eight single implants were placed in the posterior maxilla using BAOSFE technique. The implantation sites were classified into two groups according to the amount of grafted DBBM, 0.25 group (0.25g) and 0.5 group (0.5 g). Panoramic views or cone-beam computed tomography (CBCT) were taken at the time of implant placement with BAOSFE and after at least 6 months to assess the bone level changes in the elevated sites with DBBM. Results: Alveolar bone level around all implants was stable clinically and radiographically during the follow-up. Mean augmented bone height was $5.21{\pm}0.94mm$ in 0.25 group and $6.92{\pm}1.19mm$ in 0.5 group. Statistically significant difference in augmented bone height was found in the comparison between the 0.25 group and 0.5 group at the time of surgery. There was a positive correlation between the length of the implant protruding into the maxillary sinus and the augmented bone height. After 6 months, mean reduction of augmented bone height was $0.50{\pm}0.34mm$ in 0.25 group and $0.41{\pm}0.30mm$ in 0.5group. There was no specific correlation between the reduction of augmented bone height and amount of grafted DBBM. Conclusion: Within the limit of this study, the amount of grafting materials and the protrusion length of implant into the maxillary sinus affect the amount of the augmented bone height.

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.1
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• pp.79-87
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• 2021

The digital workflow of optical impressions by the intraoral scanner and CADCAM manufacture of dental prostheses is actively developing. The complex process of traditional impression taking, definite cast fabrication, wax pattern making, and casting has been shortened, and the number of patient's visits can also be reduced. Advances in intraoral scanner technology have increased the precision and accuracy of optical impression, and its indication is progressively widened toward the long span fixed dental prosthesis. This case report describes the long span implant case, and the operator fully utilized digital workflow such as computer-guided implant surgical template and CAD-CAM produced restoration after the digital impression. The provisional restoration and customized abutments were prepared with the optical impression taken on the same day of implant surgery. Moreover, the final prosthesis was fabricated with the digital scan while utilizing the same customized abutment from the provisional restoration. During the data acquisition step, stl data of customized abutments, previously scanned at the time of provisional restoration delivery, were imported and automatically aligned with digital impression data using an 'A.I. abutment matching algorithm' the intraoral scanner software. By using this algorithm, it was possible to obtain the subgingival margin without the gingival retraction or abutment removal. Using the digital intraoral scanner's advanced functions, the operator could shorten the total treatment time. So that both the patient and the clinician could experience convenient and effective treatment, and it was possible to manufacture a prosthesis with predictability.

• The Journal of Advanced Prosthodontics
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• v.8 no.5
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• pp.363-371
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• 2016

PURPOSE. On maxillofacial tumor patients, oral implant placement prior to postoperative radiotherapy can shorten the period of prosthetic reconstruction. There is still lack of research on effects of post-implant radiotherapy such as healing process or loading time, which is important for prosthodontic treatment planning. Therefore, this study evaluated the effects of post-implant local irradiation on the osseointegration of implants during different healing stages. MATERIALS AND METHODS. Custom-made implants were placed bilaterally on maxillary posterior edentulous area 4 weeks after extraction of the maxillary first molars in Forty-eight Sprague-Dawley rats. Experimental group (exp.) received radiation after implant surgery and the other group (control) didn't. Each group was divided into three sub-groups according to the healing time (2, 4, and 8 week) from implant placement. The exp. group 1, 2 received 15-Gy radiation 1 day after implant placement (immediate irradiation). The exp. group 3 received 15-Gy radiation 4 weeks after implant placement (delayed irradiation). RESULTS. The bone mineral density (BMD) was significantly lower in the immediate irradiation groups. BMD was similar in the delayed irradiation group and the control group. The irradiated groups exhibited a lower bone-to-implant contact ratio, although the difference was not statistically significant. The irradiated groups also exhibited a significantly lower bone volume and higher empty lacuna count than the control groups. No implant failure due to local irradiation was found in this study. CONCLUSION. Within the limits of this study, the timing of local irradiation critically influences the bone healing mechanism, which is related to loading time of prostheses.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.38
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• pp.1.1-1.4
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• 2016

Background: This study aimed to investigate the distribution and prevalence of intraosseous loop (anastomosis between posterior superior alveolar artery and infraorbital artery) in Koreans detected on computed tomography (CT) images taken prior to sinus augmentation surgery. Methods: From the 177 patients who underwent sinus augmentation with lateral approach at Ewha Womans University Department of Implant Dentistry, 284 CT scans were evaluated. The canal height (CH), ridge height (RH), and canal height from the sinus floor (CHS) were measured on para-axial views at the first premolar, first molar, and second molar. The horizontal positions of the bony canals in the lateral wall were also classified. One-way analysis of variance (ANOVA) and t test were used to estimate the statistical differences (p < 0.05). Results: The intraosseous loops were detected in 92 CT scans (32 %). The mean vertical height of the bony canals from the alveolar crest (CH) was $23.45{\pm}2.81$, $15.92{\pm}2.65$, and $16.61{\pm}2.92mm$ at the second premolar, first molar, and second molar, respectively. In the horizontal positions of the bony canals, intraosseous type was the most predominant. The canal heights more than 15 mm and less than 17 mm were most prevalent (33.7 %) and those under 13 mm were 12.0 %. Conclusions: The radiographic findings in this study could be used to decide the lateral osteotomy line avoiding potential vascular complication. However, only one third of the canals could be detected in CT scans; a precaution should be taken for the possibility of severe bleeding during lateral osteotomy.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.8
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• pp.4137-4140
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• 2012

The authors present five cases of combined oral mucosa-mandible defects reconstructed with the vascularized internal oblique-iliac crest myoosseous free flap. This technique has many advantages compared to other conventional methods such as the radial flap, scapula flap, and fibula flap. Vascularized iliac crest flaps provide sufficient high-quality bone suitable for reconstructing segmental madibular defects. Although fibular flaps allow longer donor bone tissue to be harvested, the iliac crest can provide an esthetic shape for mandibular body reconstruction and also provides sufficient bone height for dental implants. Conventional vascularized iliac crest myoosseous flaps have excessive soft tissue bulk for reconstruction of intraoral soft tissue defects. The modification discussed in the present article can reduce soft tissue volume, resulting in better functional reconstruction of the oral mucosa. Another advantage is that complete replacement of the oral mucosa is observed in as early as one month post-operation. The final mucosal texture is much better than that obtained with other skin paddle flaps, which is especially beneficial for the placement of dental implant prostheses. Donor site morbidity looks to be similar to, if not less than that observed for other modalities in terms of function and esthetics. For combined oral mucosa-mandible defects, the vascularized internal oblique-iliac crest myoosseous free flap shows good results with respect to hard and soft tissue reconstruction.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.42 no.1
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• pp.2-8
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• 2016

Objectives: The purpose of this study was to investigate the effects of low-level laser therapy (LLLT) with a diode gallium-aluminum-arsenide (Ga-Al-As) low-level laser device on the healing and attachment of titanium implants in bone. Materials and Methods: Thirteen New Zealand white male rabbits weighing $3.0{\pm}0.5kg$ were used for this study. Dental titanium implants (3.75 mm in diameter and 8.5 mm in length, US II RBM plus fixture; Osstem, Seoul, Korea) were implanted into both femurs of each rabbit. The rabbits were randomly divided into a LLLT group and a control group. The LLLT was initiated immediately after surgery and then repeated daily for 7 consecutive days in the LLLT group. Six weeks and 12 weeks after implantation, we evaluated and compared the osseointegration of the LLLT group and control group, using histomorphometric analysis, removal torque testing, and resonance frequency analysis (RFA). The results were statistically significant when the level of probability was 0.05 or less based on a non-parametric Mann-Whitney U-test. Results: The implant survival rate was about 96%. Histologically and histomorphometrically, we observed that the titanium implants were more strongly attached in LLLT group than in control group. However, there was no significant difference between the LLLT group and control group in removal torque or RFA. Conclusion: Histologically, LLLT might promote cell-level osseointegration of titanium implants, but there was no statistically significant effects.

• Journal of Periodontal and Implant Science
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• v.51 no.3
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• pp.179-188
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• 2021

Purpose: Due to the difficulty of the hygienic care and sanitary management of abutment teeth and subpontic areas associated with fixed dental prostheses (FDPs), intrabony defects occur and accelerate due to the accumulation of plaque and calculus. This study aimed to evaluate the efficacy of regenerative periodontal surgery for intrabony defects associated with FDPs. Methods: The study inclusion criteria were met by 60 patients who underwent regenerative treatment between 2016 and 2018, involving a total of 82 intrabony defects associated with FDPs. Periodontal osseous lesions were classified as 1-, 2-, and 3-wall intrabony defects and were treated with an enamel matrix derivative in combination with bone graft material. The changes in clinical (pocket probing depth [PPD] and clinical attachment level [CAL]) and radiographic (defect depth and width) outcomes were measured at baseline and at 6, 12, and 24 months. Results: Six months after regenerative treatment, a significant reduction was observed in the PPD of 1-wall (P<0.001), 2-wall (P<0.001), and 3-wall (P<0.001) defects, as well as a significant reduction in the CAL of 2-wall (P<0.001) and 3-wall (P<0.001) intrabony defects. However, there was a significant increase in the CAL of 1-wall intrabony defects (P=0.003). Radiographically, a significant reduction in the depth of the 3-wall (P<0.001) defects and a significant reduction in the width of 2-wall (P=0.008) and 3-wall (P<0.001) defects were observed. The depth decreased in 1-wall defects; however, this change was not statistically significant (P=0.066). Conclusions: Within the limitations of the current study, regenerative treatment of 2- and 3-wall intrabony defects associated with FDPs improved clinical and radiological outcomes. Additional prospective studies are necessary to confirm our findings and to assess long-term outcomes.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.4
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• pp.301-307
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• 2004

The flap considered at first for the reconstruction of large maxillary defect, especially mid-face defect, is scapular free flap, because it provides ample composite tissue which can be designed 3-dimensionally for orbital, facial and oral reconstruction. In case of maxillary defect involving hard palate, however, this flap has some limitations. First, its bulk prevents oral function and physio-anatomic reconstruction of nasal and oral cavity. Second, mobility and thickness of cutaneous paddle covering the alveolar area reduce retention of tissue-supported denture and give rise to peri-implantitis when implant is installed. Third, lateral border of scapula that is to reconstruct maxillary arch and hold implants is straight, not U-shaped maxillary arch form. To overcome these problems, new concept of step prefabrication technique was provided to a 27-year-old male patient who had been suffering from a complete hard palate and maxillary alveolar ridge defect. In the first stage, scapular osteomuscular flap was elevated, tailored to fit the maxillary defect, particulated autologous bone was placed subperiosteally to simulate U-shaped alveolar process, and then wrapped up with split thickness skin graft(STSG, 0.3mm thickness). Two months later, thus prefabricated new flap was elevated and microtransferred to the palato-maxillary defect. After 6 months, 10 implant fixtures were installed along the reconstructed maxillary alveolus, with following final prosthetic rehabilitation. The procedure was very successful and patient is enjoying normal rigid diet and speech.

• Korean Journal of Cleft Lip And Palate
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• v.6 no.2
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• pp.91-105
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• 2003

There are significant limitations in the precision of mandibular distraction in setting a desired occlusal and facial esthetic outcome. The purpose of this study is to present the simulation method for the distraction osteogenesis treatment planning. 3-D surgery simulation software programs V-works and V-Surgery(Cybermed, Seoul, Korea) were used from the 3D CT data in addition to the conventional data facial photography, panorama and cephalogram, dental cast model. We have utilized already for the various surgical procedures to get information preoperatively for the maxillofacial surgery like cancer localization and reconstructive surgery, orthognathic surgery and implant surgery in the department of Oral and Maxillofacial surgery, Seoul National University Hospital. On the software, bone cutting can be done at any place and any direction. Separated bone segment can be mobilized in all 3 dimensional direction. After the 3D simulation on the software program, mock surgery on the RP model can be performed. This planning method was applied to two hemifacial microsomia patients. With this protocol, we could simulate the movement of bony segment after maxillofacial distraction osteogenesis

• Maxillofacial Plastic and Reconstructive Surgery
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• v.23 no.5
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• pp.406-414
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• 2001

In recent decade, there has been a very rapid development in technical possibilities to provide patients with maxillofacial prostheses. Dr. Brenemark first introduced possibility of use of maxillofacial interosseous implant in patients with ablative tumor surgery in 1979. He did introduce the new type of maxillofacial implants system which widen the fixture flange on top of the bone. The advantages of fixed prostheses with implants were well known to various ways, easy to attach, keep clean prostheses, and not to disturb recipient bed. But there are some problems to install implants on maxillofacial regions, because mostly facial bone has very thin cortical bone and poor bone quality. It needs more retention between implant and bone which overcome that fault with fixture flange. To make maxillofacial prostheses, it should be understood general procedure of maxillofacial laboratory work. Ear and midface maxillofacial fabrication which include nose and eye defects will be described step by step.