• Archives of Craniofacial Surgery
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• v.9 no.2
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• pp.45-50
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• 2008

Purpose: Traditionally, titanium miniplate has been used for rigid fixation of mandible fractures. However, the limitations of metal plate have been reported such as hypersensitivity, interference with the cranio-facial growth of growing child, secondary bone resorption around the plate, foreign body reaction, declination of primary callus formation, and bone atrophy, and so forth. Recently, biodegradable miniplate has been introduced and used as an alternative to the metal plate despite of its lower strength. This study evaluated the usefulness and stability of biodegradable plate and screw for treatment of mandible fractures. Methods: In this study, 61 patients(92 areas) diagnosed as mandible fracture in the last 2 years have been reviewed. We used titanium plate and screw in 32 patients, and biodegradable plate and screw($INION^{(R)}$) in 29 patients. Stability of plates and screws, bony healing process and its side effects were observed by clinical and radiographic assessment. Results: In the titanium material group, one of malocclusion, two of mouth opening limitation, three of pain, three of palpation were shown. The plate of six patients involved in these complications were removed. In the biodegradable group, two of mouth opening limitation, two of pain, one of localized wound infection were shown and one plate was removed secondarily. Conclusion: There was no statistical difference between two groups in bony healing and complication rates. Biodegradable implants show efficient stability during initial bone healing and low side effects in long-term follow up periods.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.28 no.4
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• pp.249-255
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• 2002

Recently, Skeletal Anchorage System (SAS) has been focused clinically with the view point that it could provide the absolute intraoral anchorage. First, it began to be used for the patient of orthognathic surgery who had difficulty in taking intermaxillary fixation due to multiple loss of teeth. And then, its uses have been extended to many cases, the control of bone segments after orthognathic surgery, stable anchorage in orthodontic treatment, and anchorage for temporary prosthesis and so on. SAS has been developed as dental implants technique has been developed and also called in several names; mini-screw anchorage, micro-screw anchorage, mini-implant anchorage, micro-implant anchorage (MIA), and orthosystem implant etc. Now many clinicians use SAS, but the anatomical knowledges for the installed depth of intraosseous screws are totally dependent on general experiences. So we try to study for the cortical thickness of maxilla and mandible in Korean adults without any pathologic conditions with the use of Computed Tomography at the representative sites for the screw installation.

• Journal of Korean Neurosurgical Society
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• v.44 no.1
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• pp.8-14
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• 2008

Objective : The purpose of this study was to determine the efficacy of short segment fixation following postural reduction for the re-expansion and stabilization of unstable burst fractures in patients with osteoporosis. Methods : Twenty patients underwent short segment fixation following postural reduction using a soft roll at the involved vertebra in cases of severely collapsed vertebrae of more than half their original height. All patients had unstable burst fracture with canal compromise, but their motor power was intact. The surgical procedure included postural reduction for 2 days and bone cement-augmented pedicle screw fixations at one level above, one level below and the fractured level itself. Imaging and clinical findings, including the level of the vertebra involved, vertebral height restoration, injected cement volume, local kyphosis, clinical outcome and complications were analyzed. Results : The mean follow-up period was 15 months. The mean pain score (visual analogue scale) prior to surgery was 8.1, which decreased to 2.8 at 7 days after surgery. The kyphotic angle improved significantly from $21.6{\pm}5.8^{\circ}$ before surgery to $5.2{\pm}3.7^{\circ}$ after surgery. The fraction of the height of the vertebra increased from 35% and 40% to 70% in the anterior and middle portion. There were no signs of hardware pull-out, cement leakage into the spinal canal or aggravation of kyphotic deformities. Conclusion : In the management of unstable burst fracture in patients with severe osteoporosis, short segment pedicle screw fixation with bone cement augmentation following postural reduction can be used to reduce the total levels of pedicle screw fixation and to correct kyphotic deformities.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.29 no.6
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• pp.438-443
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• 2003

Purpose : This study evaluated the usefulness of resorbable plate and screw for treatment of maxillofacial bone fractures. Patients and methods : From july, 2000 to july, 2002, we used resorbable plates and screws($Biosorb^{(R)}$ FX, Bionix Inc, Finland) on 126 patients for treatment of maxillofacial bone fractures. Among them, 80 patients were capable of periodic following up to present season. We evaluated these patients with clinical, radiographic findings and subjective satisfaction. Results : 80 patients composed of 63 men and 17 women. Complication rates are 7.5%(6/80) recorded. 1 of bulging sensation, 3 of infection sign, 2 of the plate detachment were shown. The plates involved in such complications were removed. The other patients(92.5%) were not shown any problems. We could not find complete resorption of screw holes in the mandibular symphysis area even though two years later after surgery. Conclusion : Bioresorbable plates and screws are useful as fixation material at maxillofacial fractures although strength is thought to be weaker than titanium plate. But to reduce the possible complicaions, need to careful clinical and radiographical evaluations.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.49 no.1
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• pp.43-48
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• 2023

The biocompatibility and durability of implant fixtures are major concerns for dentists and patients. Mechanical complications of the implant include abutment screw loosening, screw fracture, loss of implant prostheses, and implant fracture. This case report aims to describe management of a case of fixture damage that occurred after screw fracture in a tissue level, internal connection implant and microscopic evaluation of the fractured fixture. A trephine bur was used to remove the fixture, and the socket was grafted using allogeneic bone material. The failed implant was examined by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS), which revealed a fractured fixture with both normal and irregular bone patterns. The SEM and EDS results give an enlightenment of the failed fixture surface micromorphology with microfracture and contaminated chemical compositions. Noticeably, the significantly high level of gold (Au) on the implant surface and the trace amounts of Au and titanium (Ti) in the bone tissue were recorded, which might have resulted from instability and micro-movement of the implant-abutment connection over an extended period of time. Further study with larger number of patient and different types of implants is needed for further conclusion.

• The Journal of Korea Assosiation for Disability and Oral Health
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• v.11 no.1
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• pp.5-8
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• 2015

Neuroblastoma is a common malignant tumor of the sympathetic nervous system in childhood, arises from embryonic neural crest cells. The period of tooth development is matched with peak times of diagnosis and treatment of neuroblastoma. The intensive multimodality treatment including radiotherapy and chemotherapy is used in patients with neuroblastoma has been shown to have late adverse effects and disturbances in dental development like tooth agenesis, microdontia, enamel hypoplasia and short roots. A 8-year old girl had been on medication and radiotherapy for neuroblastoma since she was 15 months old at Department Pediatrics, Chonnam National University Hospital. Oligodontia, microdontia, and short root formation was notable in clinical and radiological examination. Mobility of lower permanent incisor was detected and measured at about degree 2. Resin wire splint using mini-screw implantation on buccal alveolar bone was conducted for maintenance of mandibular incisors and alveolar bone. Excessive mobility has been eliminated and maintained well so far. Further treatment is planned for re-evaluation of mobility, preventing dental caries and regular oral hygiene management. Although we need further evaluation, this treatment could be one of alternative therapy for those who have similar dental anomalies.

• Journal of Korean Neurosurgical Society
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• v.50 no.1
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• pp.17-22
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• 2011

Objective : In the present study, authors retrospectively reviewed the clinical outcomes of halo-vest immobilization (HVI) versus surgical fixation in patients with odontoid fracture after either non-surgical treatment (HVI) or with surgical fixation. Methods : From April 1997 to December 2008, we treated a total of 60 patients with upper cervical spine injuries. This study included 31 (51.7%) patients (22 men, 9 women; mean age, 39.3 years) with types II and III odontoid process fractures. The average follow-up was 25.1 months. We reviewed digital radiographs and analyzed images according to type of injury and treatment outcomes, following conservative treatment with HVI and surgical management with screw fixation. Results : There were a total of 31 cases of types II and III odontoid process fractures (21 odontoid type II fractures, 10 type III fractures). Fifteen patients underwent HVI (10 type II fractures, 5 type III fractures). Nine (60%) out of 15 patients who underwent HVI experienced successful healing of odontoid fractures. The mean period for bone healing was 20.2 weeks. Sixteen patients underwent surgery including anterior screw fixation (6 cases), posterior C1-2 screw fixation (8), and transarticular screw fixation (2) for healing the odontoid fractures (11 type II fractures, 5 type III fractures). Fifteen (93.8%) out of 16 patients who underwent surgery achieved healing of cervical fractures. The average bone healing time was 17.6 weeks. Conclusion : The overall healing rate was 60% after HVI and 93.8% with surgical management. Patients treated with surgery showed a higher fusion rate and shorter bony healing time than patients who received HVI. However, prospective studies are needed in the future to define better optimal treatment and cost-effective perspective for the treatment of odontoid fractures.

• The Journal of Advanced Prosthodontics
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• v.7 no.6
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• pp.423-430
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• 2015

PURPOSE. To evaluate the cumulative survival rate (CSR) and mechanical complications of single-tooth $Ankylos^{(R)}$ implants. MATERIALS AND METHODS. This was a retrospective clinical study that analyzed 450 single $Ankylos^{(R)}$ implants installed in 275 patients between December 2005 and December 2012. The main outcomes were survival results CSR and implant failure) and mechanical complications (screw loosening, fracture, and cumulative fracture rate [CFR]). The main outcomes were analyzed according to age, sex, implant length or diameter, bone graft, arch, and position. RESULTS. The 8-year CSR was 96.9%. Thirteen (2.9%) implants failed because of early osseointegration failure in 3, marginal bone loss in 6, and abutment fracture in 4. Screw loosening occurred in 10 implants (2.2%), and 10 abutment fractures occurred. All abutment fractures were located in the neck, and concurrent screw fractures were observed. The CSR and rate of screw loosening did not differ significantly according to factors. The CFR was higher in middle-aged patients (5.3% vs 0.0% in younger and older patients); for teeth in a molar position (5.8% vs 0.0% for premolar or 1.1% for anterior position); and for larger-diameter implants (4.5% for 4.5 mm and 6.7% for 5.5 mm diameter vs 0.5% for 3.5 mm diameter) (all P<.05). CONCLUSION. The $Ankylos^{(R)}$ implant is suitable for single-tooth restoration in Koreans. However, relatively frequent abutment fractures (2.2%) were observed and some fractures resulted in implant failures. Middle-aged patients, the molar position, and a large implant diameter were associated with a high incidence of abutment fracture.

• Clinics in Shoulder and Elbow
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• v.20 no.3
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• pp.147-152
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• 2017

Background: To evaluate the clinical and functional outcomes of arthroscopic-assisted reduction and percutaneous screw fixation for glenoid fractures with scapular extension, and investigate the radiologic and clinical benefits from the results. Methods: We evaluated patients treated with arthroscopic-assisted reduction and percutaneous screw fixation for glenoid fractures with scapular extension from November 2008 to September 2015. Fractures with displacement exceeding one-fourth of the anterior-articular surface or more than one-third of the posterior-articular surface in radiographic images were treated by surgery. Clinical assessment was conducted based on range of motion, Rowe score, and Constant score of injured arm and uninjured arm at last follow-up. Results: Fifteen patients with Ideberg classification grade III, IV, and V glenoid fracture who underwent arthroscopic-assisted reduction using percutaneous screw fixation were retrospectively enrolled. There were no differences in clinical outcomes at final follow-up compared to uninjured arm. Bone union was seen in all cases within five months, and the average time to bone union was 15.2 weeks. Ankylosis in one case was observed as a postoperative complication, but the symptoms improved in response to physical therapy for six months. There was no failure of fixation and neurovascular complication. Conclusions: We identified acceptable results upon radiological and clinical assessment for the arthroscopic-assisted reduction and percutaneous fixation. For this reason, we believe the method is favorable for the treatment of Ideberg type III, IV, and V glenoid fractures. Restoration of the articular surface is considered to be more important than reduction of fractures reduction of the scapula body.

• Journal of Dental Rehabilitation and Applied Science
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• v.21 no.1
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• pp.1-14
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• 2005

The purpose of this study was to assess the loading distributing characteristics of implant prosthesis of internal connection system(ITI system) according to position and direction of load, under vertical and inclined loading using finite element analysis (FEA). The finite element model of a synOcta implant and a solid abutment with $8^{\circ}$ internal conical joint used by the ITI implant was constructed. The gold crown for mandibular first molar was made on solid abutment. Each three-dimensional finite element model was created with the physical properties of the implant and surrounding bone. This study simulated loads of 200N at the central fossa in a vertical direction (loading condition A), 200N at the outside point of the central fossa with resin filling into screw hole in a vertical direction (loading condition B), 200N at the centric cusp in a $15^{\circ}$ inward oblique direction (loading condition C), 200N at the in a $30^{\circ}$ inward oblique direction (loading condition D) or 200N at the centric cusp in a $30^{\circ}$ outward oblique direction (loading condition E) individually. Von Mises stresses were recorded and compared in the supporting bone, fixture, and abutment. The following results have been made based on this study: 1. Stresses were concentrated mainly at the ridge crest around implant under both vertical and oblique loading but stresses in the cancellous bone were low under both vertical and oblique loading. 2. Bending moments resulting from non-axial loading of dental implants caused stress concentrations on cortical bone. The magnitude of the stress was greater with the oblique loading than with the vertical loading. 3. An offset of the vertical occlusal force in the buccolingual direction relative to the implant axis gave rise to increased bending of the implant. So, the relative positions of the resultant line of force from occlusal contact and the center of rotation seems to be more important. 4. In this internal conical joint, vertical and oblique loads were resisted mainly by the implant-abutment joint at the screw level and by the implant collar. Conclusively, It seems to be more important that how long the distance is from center of rotation of the implant itself to the resultant line of force from occlusal contact (leverage). In a morse taper implant, vertical and oblique loads are resisted mainly by the implant-abutment joint at the screw level and by the implant collar. This type of implant-abutment connection can also distribute forces deeper within the implant and shield the retention screw from excessive loading. Lateral forces are transmitted directly to the walls of the implant and the implant abutment mating bevels, providing greater resistance to interface opening.