, Hee-Kyun Oh 2 ·Abstract Purpose: This research sought to determine the resorption rate of bone grafted to the maxillary sinus according to the grafted material's type, patient's age, systemic disease, implant size, site of implant placement, and residual ridge height. Materials and Methods: This research targeted 24 patients who had immediate Osstem ® implant (US Plus ® ) placement after bone graft. The panorama was taken before the surgery, after the surgery, and 6 months after the surgery. Vertical height change and resorption rate of the grafted bone were measured with the same X-rays and compared. The influence of the following factors on the grafted bone material's resorption rate was evaluated: grafted material type, patient's age, systemic disease, implant size, site of implant placement, and residual ridge height. Results: Patients in their 40s had 34.0±21.1% resorption rate, which was significantly higher compared to the other age groups (P<0.05). There was no significant relationship between systemic disease and grafted bone resorption. There was no significant relationship between implant size (diameter, length) and grafted bone resorption. There was no significant relationship between the site of implant placement and grafted bone resorption. The ramal bone-grafted site was significantly more resorbed than the ramal bone/Bio-Oss ® -grafted site, maxillary tuberosity bone/Bio-Oss ® -grafted site, and ramal bone/maxillary tuberosity bone/Bio-Oss ® -grafted site (P<0.05). There was no significant difference in the grafted bone resorption rate in the sinus between more than 4 mm and less than 4 mm residual ridge heights. After an average of 6 months, a second surgery was done; given an average follow-up of 1.9 years, the success rate and survival rate of the implant were 96.9% and 98.4%, respectively. Conclusion: These results indicate that the bone resorption rate of grafted bone among patients in their 40s is higher compared to patients in their 50s and over, and that only autogenous bone (ramus) shows higher resorption rate than the mixed graft of autogenous bone and xenogenous graft (Bio-oss) after maxillary sinus graft.

Introduction: The purpose of this study is to evaluate the clinical results of vertical alveolar ridge augmentation using autogenous block bone graft, especially resorption rate, and outcomes of dental implants placed in the grafted site. Patients and Methods: Medical records and radiographs were reviewed. Twenty-seven patients who have been received the autogenous block bone graft which harvested from chin, ramus, and ilium, and the implant installation on 31 areas(22 maxillas and 9 mandibles) were included. Eight implants were installed simultaneously at the time of bone graft in 4 patients, and 65 implants were installed after 4.9 months(range 2~18 months) of autogenous block bone graft in 23 patients. The resorption amount and rate of augmented bone, and the success and survival rates implants were evaluated. Results: Mean height of the augmented block bone was 5.9pm2.3mm(range from 2.5 to 13.0 mm). Mean follow-up period after block bone graft was 30.4 months(range from 16 to 55 months). Mean resorption of the augmented block bone was 2.0pm1.5mm (range from 0.5 to 7.24 mm). The success and survival rates of the implants were 78.1 % and 98.6%, respectively. Conclusion: This study indicates that the autogenous block bone graft is a useful and stable method for alveolar ridge augmentation for dental implant. And more augmentation is needed to compensate the resorption of the grafted bone.

Purpose: This study evaluated postoperative maxillary stabilities in patients with skeletal Class III malocclusion who were taken both maxillary advancement surgery and mandibular retrusive surgery, using Le Fort I osteotomy, through three-dimensional computed tomography. Methods: We selected 14 patients who were taken postoperative three-dimensional computerized tomography at the time before surgery, immediately after surgery, six months after surgery among the patients undergone both maxillary advancement surgery using Le Fort I osteotomy and mandibular retrusive surgery using bilateral sagittal split ramus osteotomy. We measured and compared the vertical distance of A-point and posterior nasal spine (PNS), the horizontal distance of A-point and PNS in transverse plane and coronal plane of the three-dimensional reconstructed images, respectively. Results: In transverse plane, the distance difference between immediately after surgery (S1) and immediately before surgery (S0) of A-point was 0.04±1.80 mm, S2 and S0 was 0.15±1.69 mm, and between S1 and S2 was 0.11±0.58 mm. There were no significant differences between these data (P ＞0.05). In transverse plane, the distance between S1-S0 of PNS was 3.87±2.37 mm, S2-S0 of PNS was 3.79±2.39 mm, and S1-S2 of PNS was 0.08±0.18 mm. There were significant differences between these data (P ＜0.05). In coronal plane, the distance between S1-S0 of A-point was 3.99±0.86 mm, S2-S0 was 3.57±1.09 mm, and S1-S2 was 0.42±0.42 mm. There were significant differences between these data (P ＜0.05). In coronal plane, the distance between S1-S0 of PNS was 3.82±0.96 mm, S2-S0 was 3.43±0.91 mm, and S1-S2 was 0.39±0.49 mm. There were significant differences between these data (P ＜0.05). In transverse plane, it was estimated that PNS has no statistical postoperative stability in the same direction. In coronal plane, it was estimated that both A-point and PNS had no statistical postoperative stability (P ＜0.05). Conclusion: Clinically, the operation plan needs to take into account of the maxillary relapse.