• The Journal of Advanced Prosthodontics
• /
• v.3 no.4
• /
• pp.204-215
• /
• 2011

PURPOSE. The aim of this retrospective study is to analyze the relationship between local factors and survival rate of dental implant which had been installed and restored in Seoul Veterans Hospital dental center for past 10 years. And when the relationship is found out, it could be helpful to predict the prognosis of dental implants. MATERIALS AND METHODS. A retrospective study of patients receiving root-shaped screw-type dental implants placed from January 2000 to December 2009 was conducted. 6385 implants were placed in 3755 patients. The following data were collected from the dental records and radiographs: patient's age, gender, implant type and surface, length, diameter, location of implant placement, bone quality, prosthesis type. The correlations between these data and survival rate were analyzed. Statistical analysis was performed with the use of Kaplan-Meier analysis, Chi-square test and odds ratio. RESULTS. In all, 6385 implants were placed in 3755 patients (3120 male, 635 female; mean age $65{\pm}10.58$ years). 108 implants failed and the cumulative survival rate was 96.33%. There were significant differences in age, implant type and surface, length, location and prosthesis type (P<.05). No significant differences were found in relation to the following factors: gender, diameter and bone quality (P>.05). CONCLUSION. Related factors such as age, implant type, length, location and prosthesis type had a significant effect on the implant survival.

• Archives of Craniofacial Surgery
• /
• v.10 no.1
• /
• pp.33-36
• /
• 2009

Purpose: Fractures of the mandibular condylar area are common injuries that account for 29% to 40% of fractures of the facial bones and represent 20% to 62% of all mandibular fractures. Currently 3 main methods are being used in the treatment of mandibular subcondylar fractures: closed reduction; open reduction and internal fixation; Endoscopic reduction and internal fixation. Each method has its proponents and opponent as well as advantages and disadvantages, and indications for each vary among surgeons. There are six approaches of open reduction: submandibular, retromandibular, preaurilcular, postauricular, intraoral, transparotid approach. Among them, transparotid approach has been described for subcondylar exposure with dissection in the direction of facial nerve fibers to expose the bone through the parotid gland. This approach carries the risk of a parotid glandular fistula as well as facial nerve injury but has the advantage of being directly over the fracture site. We report safety and efficacy of surgical treatment using a transparotid approach for direct plating. Methods: A 43-year-old man sustained multiple facial bone fractures by driver traffic accident. Mandibular subcondyle was fractured and dislocated internally. We performed open reduction and internal fixation by transparotid approach. Fractured site was fixed by titanium mini plate & screw. We applicated arch bar for approximately 3 weeks. Results: Follow-up length was about 5months. Scar of surgical incision was indistinct, there was no symptoms and signs of facial nerve and parotid gland injury, and maximal mouth opening was measured 49.5 mm. Conclusion: Transparotid approach has high risks of facial nerve and parotid gland injury, but paradoxically it is the most effective technique in saving facial nerve. Open reduction and internal fixation of mandibular subcondylar fracture by transparotid approach with precise and versed procedure, best outcome can be expected.

• The korean journal of orthodontics
• /
• v.50 no.5
• /
• pp.346-355
• /
• 2020

The treatment of skeletal Class III malocclusion in adolescents is challenging. Maxillary protraction, particularly that using bone anchorage, has been proven to be an effective method for the stimulation of maxillary growth. However, the conventional procedure, which involves the surgical implantation of mini-plates, is traumatic and associated with a high risk. Three-dimensional (3D) digital technology offers the possibility of individualized treatment. Customized mini-plates can be designed according to the shape of the maxillary surface and the positions of the roots on cone-beam computed tomography scans; this reduces both the surgical risk and patient trauma. Here we report a case involving a 12-year-old adolescent girl with skeletal Class III malocclusion and midface deficiency that was treated in two phases. In phase 1, rapid maxillary expansion and protraction were performed using 3D-printed mini-plates for anchorage. The mini-plates exhibited better adaptation to the bone contour, and titanium screw implantation was safer because of the customized design. The orthopedic force applied to each mini-plate was approximately 400-500 g, and the plates remained stable during the maxillary protraction process, which exhibited efficacious orthopedic effects and significantly improved the facial profile and esthetics. In phase 2, fixed appliances were used for alignment and leveling of the maxillary and mandibular dentitions. The complete two-phase treatment lasted for 24 months. After 48 months of retention, the treatment outcomes remained stable.

• Journal of Periodontal and Implant Science
• /
• v.50 no.2
• /
• pp.97-105
• /
• 2020

Purpose: The present retrospective clinical study aimed to evaluate and compare the clinical and radiographic parameters, complications, and satisfaction in patients who received fixed prostheses supported by narrow-diameter implants (NDIs) in the anterior and posterior jaw. Methods: Patients aged ≥30 years who had NDI-supported fixed prostheses in the anterior or posterior region of either jaw for at least 2 years were included. Complications such as chipping of the crown; loosening or fracture of the screw, crown abutment, or implant; and loss of retention were recorded. Clinical peri-implant outcomes and crestal bone loss (CBL) were measured. A questionnaire was used to record responses regarding the aesthetics and function of the fixed restorations. Analysis of variance was used to assess the significance of between-group mean comparisons. The log-rank test was performed to analyze the influence of location and prosthesis type on technical complications. Results: Seventy-one patients (mean age: 39.6 years) provided informed consent with a mean follow-up duration of 53 months. Only bleeding on probing showed a statistically significant difference between NDIs in the anterior and posterior regions. The complication rate for NDIs in the posterior region was significantly higher than that for NDIs in the anterior region (P=0.041). For NDIs, CBL was significantly higher around splinted crowns than single crowns (P=0.022). Overall mean patient satisfaction was 10.34±3.65 on a visual analogue scale. Conclusions: NDIs in the anterior and posterior jaws functioned equally well in terms of periimplant soft and hard tissue health and offered acceptable patient satisfaction and reasonable complication rates.

• Archives of Plastic Surgery
• /
• v.36 no.1
• /
• pp.56-60
• /
• 2009

Purpose: Palatal fracture and mandible fracture result in instability of dental arch. Because they divide the maxillary and mandibular alveolus sagittally and / or transversely and comminute the dentition, they permit rotation of dental alveolar segments and significantly increase the potential for fracture malalignment, complicating fracture treatment. Previous treatment of palatal fracture consisted of palatal splint application and rigid palatal vault stabilization. This procedure result in patient's oral discomfort and removal of palate and screw. Mandible fracture often results in malocclusion due to widening of posterior aspect of dental arch. So we introduce more simple method using intermolar traction wiring, which can protect the widening of dental arch and rotation of dental alveolar segment. Methods: Arch bar and intermolar traction wiring with wire 1 - 0, or 2 - 0 was applied. After exposure of fracture line, neutrooclusion was maintained with intermaxillary fixation. And then open reduction & internal fixation on maxillary fracture line, commonly maxillary buttress, alveolar ridge, pyriform aperture except palatal vault or mandibular fracture line. After 1 week, intermolar traction wiring was removed. We checked occlusion and postoperative radiologic finding. Results: From June of 2007 to October of 2007, 10 patient, who have maxillary fracture with palatal fracture and mandible fracture, underwent open reduction & internal fixation with intermolar traction wiring. All have satisfactory occlusion and there were no complication, like gingiva disease, mouth opening impairment and nonunion. Conclusion: The intermolar traction wiring accompany open reduction and internal fixation can be alternative method for restoration of dental arch in facial bone fracture.

• Archives of Reconstructive Microsurgery
• /
• v.16 no.2
• /
• pp.125-132
• /
• 2007

Introduction: Ulna is nearly equal to radius in function and bony architecture and strength in forearm. But in lower extremity, fibula is 1/5 of tibia in anatomic and functional point so we can find fibula transposition is commonly used in defect of tibia. We cannot find other article about segmental forearm bone transposition in man. The purpose of this study was to report our clinical and functional result of undergoing segmented transposition of ipsilateral ulna with its own vascular supply in defect of radius in 6 cases. Material and method: From June 1994 to October 2007, 7 segmented bone transpositional grafts in forearm were performed in Kyung Hee Medical Center. The distribution of age was from 20 years old to 73 years old. There was male in 6 cases and female in 1 case. The causes of operation were giant cell tumor in 1 case and traumatic origin in 6 cases; it was nonunion in 2 cases and fracture with severe comminution in 4 cases. Ipsilaterally segmented ulna keeping its own vascular supply was transported to defect of radius in severe traumatic patients and one patient whose tumor in radius had been excised. Transported ulna was fixed to proximal and distal radius remnants by plate and screw. In one case with giant cell tumor, transported ulna was connected to radius across wrist joint as wrist joint fusion. Joint preserving procedures were performed in 6 cases with crushing injury of radius. Results: We could obtain solid bony union in all cases and good functional results. The disadvantage was relative shortening of forearm, but we could overcome this problem. Conclusion: We think that ipsilateral segmented ulna transposition keeping its own vascular supply to radius can be perfomed with one of procedures in cases with wide defect in radius.

• The Journal of the Korean dental association
• /
• v.51 no.4
• /
• pp.190-197
• /
• 2013

A titanium based screw shaped dental implant was first introduced by Branemark and a treatment protocol where the restoration of edentulous area by connecting abutment after the osseointegration of the titanium surface of the implant and surrounding bone structure has been proposed. Although this protocol is widely accepted as a standard up to date, the healing duration of 3-6 months as well as the need for provisional prostheses during this period present as a major drawback. Immediate loading has been accomplished through the advent of various implant designs, enforced surface treatments, diverse forms of abutment, and delicate surgical techniques together with the increase in demand from the patients. The success rate of the immediate loading technique has been first reported as 85.7% by Dr. Schnitman in 1990 which recently has been reported up to 100% in the case of immediate loading in single tooth by Dr. Kan. To ameliorate the success rate of immediate loading technique, selection of patients presenting a sound bone quality and quantity, acquiring primary stability through delicate surgical techniques and fabrication of prostheses which accounts for biological stabilities should all be taken into consideration. This presentation introduces the understanding of biological stability of immediate loading, various methods for measurement of stability and clinical cases regarding immediate loading technique.

• The Journal of Advanced Prosthodontics
• /
• v.13 no.6
• /
• pp.396-407
• /
• 2021

PURPOSE. Zirconia has exceptional biocompatibility and good mechanical properties in clinical situations. However, finite element analysis (FEA) studies on the biomechanical stability of two-piece zirconia implant systems are limited. Therefore, the aim of this study was to compare the biomechanical properties of the two-piece zirconia and titanium implants using FEA. MATERIALS AND METHODS. Two groups of finite element (FE) models, the zirconia (Zircon) and titanium (Titan) models, were generated for the exam. Oblique (175 N) and vertical (175 N) loads were applied to the FE model generated for FEA simulation, and the stress levels and distributions were investigated. RESULTS. In oblique loading, von Mises stress values were the highest in the abutment of the Zircon model. The von Mises stress values of the Titan model for the abutment screw and implant fixture were slightly higher than those of the Zircon model. Minimum principal stress in the cortical bone was higher in the Titan model than Zircon model under oblique and vertical loading. Under both vertical and oblique loads, stress concentrations in the implant components and bone occurred in the same area. Because the material itself has high stiffness and elastic modulus, the Zircon model exhibited a higher von Mises stress value in the abutments than the Titan model, but at a level lower than the fracture strength of the material. CONCLUSION. Owing to the good esthetics and stress controllability of the Zircon model, it can be considered for clinical use.

• The korean journal of orthodontics
• /
• v.52 no.6
• /
• pp.412-419
• /
• 2022

Objective: This study evaluated the effect of cyclic pre-calcification treatment on the improvement of bioactivity and osseointegration of Ti-6Al-4V mini-screws. Methods: The experimental groups were: an untreated group (UT), an anodized and heat-treated group (AH), and an anodized treatment followed by cyclic pre-calcification treatment group (ASPH). A bioactive material with calcium phosphate was coated on the mini-screws, and its effects on bioactivity and osseointegration were evaluated in in vitro and in vivo tests of following implantation in the rat tibia. Results: As a result of immersing the ASPH group in simulated body fluid for 2 days, protrusions appearing in the initial stage of hydroxyapatite precipitation were observed. On the 3rd day, the protrusions became denser, other protrusions overlapped and grew on it, and the calcium and phosphorus concentrations increased. The removal torque values increased significantly in the following order: UT group (2.08 ± 0.67 N·cm), AH group (4.10 ± 0.72 N·cm), and ASPH group (6.58 ± 0.66 N·cm) with the ASPH group showing the highest value (p < 0.05). In the ASPH group, new bone was observed that was connected to the threads, and it was confirmed that a bony bridge connected to the adjacent bone was formed. Conclusions: In conclusion, it was found that the surface treatment method used in the ASPH group improved the bioactivity and osseointegration of Ti-6Al-4V orthodontic mini-screws.

• Archives of Craniofacial Surgery
• /
• v.24 no.2
• /
• pp.52-58
• /
• 2023

Background: Complex orbital fractures are impure orbital fractures because they involve the orbital walls and mid-facial bones. The author reported an orbital wall restoration technique in which the primary orbital wall fragments were restored to their prior position in complex orbital fractures in 2020. As a follow-up to a previous preliminary study, this study retrospectively reviewed the surgical results of complex orbital wall fractures over a 4-year period and compared the surgical outcomes by dividing them into groups with and without balloon restoration. Methods: Data of 939 patients with facial bone fractures between August 2018 and August 2022 were reviewed. Of these, 154 had complex orbital fractures. Among them, 44 and 110 underwent reduction with and without the balloon technique respectively. Pre- and postoperative Naugle exophthalmometer (Good-Lite Co.) scales were evaluated. The orbital volume and orbital volume ratio were calculated from preoperative and 6 months postoperative computed tomography images. Results: Among 154 patients with complex orbital fractures, 44 patients underwent restoration with the balloon technique, and 110 patients underwent restoration without it. The Naugle scale did not differ significantly between the two groups, but the orbital volume ratio significantly decreased by 3.32% and 2.39% in groups with and without the balloon technique and the difference in OVR was significantly greater in patients in the balloon restoration group compared with the control group. Postoperative balloon rupture occurred in six out of 44 cases (13.64%). None of the six patients with balloon rupture showed significant enophthalmos at 6 months of follow-up. Conclusion: The balloon rupture rate was 13.64% (6/44 cases) with marginal screw fixation, blunt screws, and extra protection with a resorbable foam dressing. Furthermore, we restored the orbital wall with primary orbital fragments using balloon support in complex orbital wall fractures.