• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.37 no.6
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• pp.483-489
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• 2011

Introduction: This study examined the cumulative resorption of implants placed in a severely atrophic mandible and analyzed the radiologic bone resorption in the marginal bone, after an autogenous bone graft including both block and particulates that had been harvested from the ramus and iliac crest. Materials and Methods: A retrospective study was performed on patients who had bone grafts for augmentation followed by implant installation in the mandible area from 2003 to 2008. Twelve patients (6 men and 6 women) who received 34 implants in the augmented sites were evaluated. Cumulative radiologic resorption around the implants was measured immediately, 3 months, 6 months and 12 months after implant installation surgery. Results: The installed implant in grafted bone showed 0.84 mm marginal bone resorption after 3 months and 50% total cumulative resorption after 1 year. The mean marginal bone resorption around the implant installed in the grafted bone was 0.44 mm after 3 months, 0.52 mm after 1 year, after which it stabilized. The implant survival rate was 97% (failed implant was 1/34). Marginal bone resorption of the installed implant in the autogenous onlay block bone grafts was 0.98 mm after 3 months, which was significantly higher than that of a particulated bone graft (0.74 mm) (P <0.05). Conclusion: An autogenous graft including block type and particulate type is a predictable procedure for the use of dental implants in a severely atrophic mandible. Implant placement in augmented areas show a relatively high survival and minimal bone loss, as revealed by a radiologic evaluation.

• The Journal of the Korean dental association
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• v.51 no.8
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• pp.459-467
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• 2013

The use of autogenous tooth bone graft material has been commercialized since 2008. Autogenous tooth bone grafts always require that the tooth of the patient be extracted, and thus, the use of graft material are limited in many cases. For solution of limitation in quantity and concurrent use of autogenous tooth bone graft material, the grafting of familial teeth has been suggested. It has the following advantages: the teeth of family members are used as bone graft materials, the genetic composition is identical, and potential genetic and infectious risks can be minimized. Because the teeth of family members are used, a good tissue affinity is obtained, and thus, superior bone generation rates compared to those observed for allogenic or xenogenic bones can be anticipated. We used familial tooth bone-graft materials for alveolar ridge augmentation, socket preservation, and maxillary sinus graft in some cases. In most cases, the impacted third molars of their children were prepared as bone graft material and were used for surgery. In one case, the impacted third molar from the patient's brother was used as bone graft material. We obtained satisfactory result and these cases are reported herein.

• The Journal of the Korean dental association
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• v.48 no.3
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• pp.205-217
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• 2010

Purpose The aim of this study is to evaluate the survival rates and analyze the stability of lateral approach and trans-crestal approach for maxillary sinus floor elevation of simultaneous implant placement. Materials and method 407 patients who have been treated in LivingWell dental hospital between 2003 to 2009 were selected. Lateral window technique, osteotome technique and sinus drill technique were used for sinus floor elevation procedure. A total of 714 implants-MP-1 HA coated implant(Tapered Screw $Vent^{TM}$, $Spline^{TM}$, Zimmer, USA), FBR surfaced implant(Pitt-$Easy^{TM}$, Oraltronics, Germany)-were placed in grafted maxillary sinus simultaneously. The autogenous bone or a combination with the allograft or alloplast was grafted into sinus. Sinus floor elevation was combined with vertical/horizontal onlay bone grafts to reconstruct the defect of alveolar ridge. Results The average preoperative height of the maxillary alveolar bone was 5.78mm(range: 0.4mm~12.5mm). 14 implants failed during the healing period(lateral approach: 4, trans-crestal approach: 10) and 3 implant failed after prosthetic loading(lateral approach: 2, trans-crestal approach: 1). The cumulative survival rate of implants after 6 years was 97.6%. Trans-crestal approach(97.4%) and lateral approach(97.9%) had similar survival rates. Conclusion The results indicate that the trans-crestal approach and lateral approach for maxillary sinus elevation is a acceptable method at atrophic maxillary posterior area.

• The Journal of the Korean dental association
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• v.25 no.5 s.216
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• pp.465-477
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• 1987

This is an experimental and clinical study on the use of an autogenous frozen mandibular bone. Two aspects must be considered in the treatment of mandibular tumors: the eradication of the disease, and the maintenamce of the mandibular continuity for a good functional and esthetic results. The authors used the cryosurgical method in the dogs and the tumor of the mandible in human, which consists of partial mandibular resection; immersion of the bone in the liquid nitrogen at -196℃, followed by reimplantation of the mandibular bone in its bed. In experimental study, the mandibular segment showed favorable healing process without rejection during the cohole experimental periods. In clinical study, the frozen bone showed no antigenicity and excellent cosmetic results.

• Journal of Korean Dental Science
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• v.6 no.1
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• pp.34-40
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• 2013

Fibrous dysplasia is a benign fi bro-osseous lesion wherein normal bone is replaced with an excessive proliferation of cellular fibrous connective tissue intermixed with irregular bony trabeculae. Fibro-osseous lesions like fibrous dysplasia are often associated with non-epithelial cysts, such as simple bone cyst. The etiologic and pathogenic relationships between fi brous dysplasia and simple bone cyst have not been conclusively established. Nonetheless, the mechanism of cyst formation in fibro-osseous lesion associated with simple bone cyst can be said to differ from that of the typical simple bone cyst of the jaws. This article reports a case of bilateral lesions including fi brous dysplasia and simple bone cyst on each site and reviews the pathogenesis of cyst formation in the fibro-osseous lesion.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.41
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• pp.12.1-12.5
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• 2019

Background: Le Fort I osteotomy is one of the surgical procedures now routinely and safely performed. It is possible to move the maxilla in three dimensions, but it is necessary to separate the bones around the maxillary sinus. Therefore, with surgery, maxillary sinus mucosal thickening occurs. By knowing the changes in the sinus mucosa after surgery and the factors affecting it, it is possible to better predict the outcomes of surgery and contribute to safer surgery. In this study, thickening of maxillary sinus mucosa before and after surgery in Le Fort I osteotomy was evaluated using multidetector-row computed tomography (MDCT) images, and the changes in mucosal thickening and the related factors were examined. Methods: Using MDCT images, the maxillary sinus mucosa of 125 patients who had undergone Le Fort I osteotomy was retrospectively evaluated before surgery, 1 month after surgery, and 1 year after surgery. On the MDCT images, the maxillary sinus was judged as mucosal thickening and classified into three grades according to the proportion occupying the maxillary sinus. In the evaluation of factors related to mucosal thickening, the following eight factors were examined: sex, age, diagnosis, operating time, amount of postoperative bleeding, with/without bone graft, with/without multisegmental osteotomy, and with/without macrolide therapy after surgery. Results: The mean age at the time of surgery was 25.6 ± 8 years. Of all 125 patients, 66 had bilateral thickening, 19 had unilateral thickening, and 40 had no thickening. Factors that were significantly related to mucosal thickening were the operative time for the maxilla, bone grafts, and macrolide therapy after surgery. Conclusions: Operative time for the maxilla, bone grafts, and macrolide therapy after surgery were found to be related to mucosal thickening. In addition, MDCT scanning 1 month after surgery was considered to be appropriate for evaluation of maxillary sinus mucosal thickening.

• Journal of Korean Dental Science
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• v.8 no.2
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• pp.65-73
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• 2015

Purpose: Parathyroid hormone (PTH) therapy has drawn attention, as an alternative to anti-resorptive drugs since PTH accelerates bone density by anabolic action. The purpose of this study was to identify the effect of intermittent PTH administration on jaw bones of rat undergone bilateral ovariectomy. Materials and Methods: Nine female Sprague-Dawley rats were divided into three groups. PTH group was ovariectomized (OVX) to induce osteoporosis and PTH $30{\mu}g/kg$ was administered 1 week after the surgery. In OVX group, ovariectomy was performed and only vehicle was administered by subcutaneous injection 3 times per week. Control group was subjected to sham surgery. The animals were sacrificed 8 weeks after the surgery and specimens were obtained from ilium and upper and lower jaw bones. Histological investigation was carried out by using an optical microscope and micro-computed tomography was taken to examine structural property changes in each bone sample. Result: In the ilium, the bone volume ratio (bone volume/total volume, BV/TV) of PTH, OVX and control groups was $53.75%{\pm}7.57%$, $50.61%{\pm}12.89%$, $76.20%{\pm}5.92%$ (P=0.061) and bone mineral density (BMD) was $1.12{\pm}0.09$, $0.88{\pm}0.48$, $1.38{\pm}0.07g/cm^3$ (P=0.061). In the mandible, BV/TV of PTH, OVX and control groups was $64.60%{\pm}12.17%$, $58.26%{\pm}9.63%$, $67.54%{\pm}14.74%$(P=0.670) and BMD was $1.21{\pm}0.17$, $1.19{\pm}0.13$, $1.27{\pm}0.18g/cm^3$ (P=0.587). In the maxilla, BV/TV of PTH, OVX and control groups was $61.19%{\pm}8.92%$, $52.50%{\pm}11.22%$, $64.60%{\pm}12.17%$ (P=0.430) and BMD was $1.20{\pm}0.11$, $1.11{\pm}0.16$, $1.21{\pm}0.17g/cm^3$ (P=0.561). No statistically significant difference was found in any variables in all groups. Histological observation revealed that the ilium in OVX group demonstrated sparsely formed trabecular bones compared with other groups. However, upper and lower trabecular bones did not present significant differences. Conclusion: Intermittent administration of PTH appears to affect the microstructure of rat jaw bones, but statistical significance was not found. However, the measurements in this study partly implicated the possible anabolic effect of PTH in vivo.

• Journal of Korean Dental Science
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• v.4 no.2
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• pp.79-84
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• 2011

The extracted right mandibular third molar of a 37-year-old man was transplanted into the first molar area, and a bone graft procedure using autogenous tooth-bone graft material was performed for the space between the root and the alveolar socket. Reattachment was achieved after 10 months. Therefore, autogenous tooth-bone graft material is considered reasonable for bone induction and healing in the autotransplantation of teeth.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.3
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• pp.102-108
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• 2016

A dental ultrasonic surgical instrument, commercially known as a scaler, is a high-value-added advanced technology that is used for tartar removal, implant operations, and gum and jaw bone surgery. In this study, the piezoelectric phenomenon for making linear motion associated with input electrical signals was studied, and the behavior of the ultrasonic vibrator was investigated by using the commercially available finite element program ANSYS(R) for the purpose of designing dental surgery tools. Modal analysis was carried out, and the optimal frequency range was calculated from the analyzed results. The ultrasonic vibrator was then redesigned based on the calculated optimal frequency range. The performance of the system was tested, and consequently, the proposed methodology was proven useful in vibrator design.

• Journal of Korean society of Dental Hygiene
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• v.18 no.4
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• pp.525-533
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• 2018

Objectives: This retrospective study evaluated the changes in the airway width after the orthognathic surgery associated with the skeletal Class III malocclusion. Methods: The lateral cephalograms of 30 adult patients were taken before and immediately after the operation, and after the orthodontic treatment. The angles and distances of them were measured and compared. Results: Before the surgery, the mean value of mandibular (S-B) setback was 9.66 mm, and moved by 1.56 mm anteriorly after the orthodontic treatment. The ANB increased by 5.42 degrees, since then it decreased by 0.68 degree. The hyoid bone (S-APH) moved by 5.05 mm posteriorly, but then moved by 2.26 mm anteriorly. The soft tissue width of laryngeal pharynx (apw2-ppw2) was narrowed by 1.04 mm, and decreased by additional 0.83 mm after the orthodontic treatment. Conclusions: As the mandible was moved back, the location of hyoid bone and laryngeal pharynx were moved backward.