• The korean journal of orthodontics
• /
• v.53 no.2
• /
• pp.125-136
• /
• 2023

Before progress was recently made in the application of temporary anchorage devices (TADs) in bio-mechanical design, orthodontists were rarely able to intrude molars to reduce upper posterior dental height (UPDH). However, TADs are now widely used to intrude molars to flatten the occlusal plane or induce counterclockwise rotation of the mandible. Previous studies involving clinical or animal histological evaluation on changes in periodontal conditions after molar intrusion have been reported, however, studies involving human histology are scarce. This case was a Class I malocclusion with a high mandibular plane angle. Upper molar intrusion with TADs was performed to reduce UPDH, which led to counterclockwise rotation of the mandible. After 5 months of upper molar intrusion, shortened clinical crowns were noticed, which caused difficulties in oral hygiene and hindered orthodontic tooth movement. The mid-treatment cone-beam computed tomography revealed redundant bone physically interfering with buccal attachment and osseous resective surgeries were followed. During the surgeries, bilateral mini screws were removed and bulging alveolar bone and gingiva were harvested for biopsy. Histological examination revealed bacterial colonies at the bottom of the sulcus. Infiltration of chronic inflammatory cells underneath the non-keratinized sulcular epithelium was noted, with abundant capillaries being filled with red blood cells. Proximal alveolar bone facing the bottom of the gingival sulcus exhibited active bone remodeling and woven bone formation with plump osteocytes in the lacunae. On the other hand, buccal alveolar bone exhibited lamination, indicating slow bone turnover in the lateral region.

• Journal of Korean Foot and Ankle Society
• /
• v.19 no.4
• /
• pp.181-187
• /
• 2015

Purpose: The purpose of this study is to retrospectively analyze the clinical results of screws and Kirschner wire (K-wire) fixation in patients with fracture dislocation of Lisfranc joint and the consequence of screw breakage. Materials and Methods: Sixty patients underwent Lisfranc joint open reduction and removal of internal fixators from January 2007 to December 2011. Forty-nine cases (81.7%) underwent operations with screw alone, and 11 cases (18.3%) underwent operations with both screws and K-wires. Type of internal fixators, duration of internal fixator removal, breakage of internal fixators and satisfaction with reduction were investigated. Additionally, American Orthopaedic Foot and Ankle Society (AOFAS) midfoot scales were analyzed. Results: The internal fixator was broken in 5 cases (8.3%). The average duration of instrument removal was 154 days in the non-broken screw group and 268.6 days in the broken screw group (p<0.05). The average AOFAS midfoot scale was 77.4 in the non-broken screw group and 74.2 in the broken screw group. The most commonly damaged portion was the first tarsometatarsal (Lisfranc) joint. Conclusion: Treatment with screws and K-wires was effective in patients with fracture dislocation of Lisfranc joint. The appropriate time for screw removal should be considered.

• Archives of Plastic Surgery
• /
• v.43 no.1
• /
• pp.40-45
• /
• 2016

Background Bioabsorbable plates and screws are commonly used to reduce maxillofacial bones, particularly in pediatric patients because they degrade completely without complications after bone healing. In this study, we encountered eight cases of a delayed foreign body reaction after surgical fixation with bioabsorbable plates and screws. Methods A total of 234 patients with a maxillofacial fracture underwent surgical treatment from March 2006 to October 2013, in which rigid fixation was achieved with the Inion CPS (Inion, Tampere, Finland) plating system in 173 patients and Rapidsorb (Synthes, West Chester, PA, USA) in 61 patients. Their mean age was 35.2 years (range, 15-84 years). Most patients were stabilized with two- or three-point fixation at the frontozygomatic suture, infraorbital rim, and anterior wall of the maxilla. Results Complications occurred in eight (3.4%) of 234 patients, including palpable, fixed masses in six patients and focal swelling in two patients. The period from surgical fixation to the onset of symptoms was 9-23 months. Six patients with a mass underwent secondary surgery for mass removal. The masses contained fibrous tissue with a yellow, grainy, cloudy fluid and remnants of an incompletely degraded bioabsorbable plate and screws. Their histological findings demonstrated a foreign body reaction. Conclusions Inadequate degradation of bioabsorbable plates caused a delayed inflammatory foreign body reaction requiring secondary surgery. Therefore, it is prudent to consider the possibility of delayed complications when using bioabsorbable plates and surgeons must conduct longer and closer follow-up observations.

• Journal of Korean Neurosurgical Society
• /
• v.52 no.2
• /
• pp.114-119
• /
• 2012

Objective : The purpose of this study was 1) to analyze clinically-executed cervical lateral mass screw fixation by the Kim's technique as suggested in the previous morphometric and cadaveric study and 2) to examine various complications and bicortical purchase that are important for b-one fusion. Methods : A retrospective study was done on the charts, operative records, radiographs, and clinical follow up of thirty-nine patients. One hundred and seventy-eight lateral mass screws were analyzed. The spinal nerve injury, violation of the facet joint, vertebral artery injury, and the bicortical purchases were examined at each lateral mass. Results : All thirty-nine patients received instrumentations with poly axial screws and rod systems, in which one hundred and seventy-eight screws in total. No vertebral artery injury or nerve root injury were observed. Sixteen facet joint violations were observed (9.0%). Bicortical purchases were achieved on one hundred and fifty-six (87.6%). Bone fusion was achieved in all patients. Conclusion : The advantages of the Kim's technique are that it is performed by using given anatomical structures and that the complication rate is as low as those of other known techniques. The Kim's technique can be performed easily and safely without fluoroscopic assistance for the treatment of many cervical diseases.

• Journal of Korean Foot and Ankle Society
• /
• v.24 no.3
• /
• pp.107-112
• /
• 2020

Purpose: Hallux valgus (HV) is a common foot deformity that causes pain in the first metatarsophalangeal joint. Distal metatarsal osteotomies are commonly performed as a treatment. This retrospective study compared the clinical and radiological results of bioabsorbable magnesium (Mg) versus titanium (Ti) screw fixation for modified distal chevron osteotomy in HV. Materials and Methods: Forty-nine patients, who underwent modified distal chevron osteotomy for HV in 2018 and 2019, were reviewed retrospectively. Bioabsorbable Mg screw fixation was applied in 20 patients (22 feet), and a traditional Ti compression screw was applied in 29 patients (40 feet). The patients were followed up for at least six months. The clinical results were evaluated using the American Orthopaedic Foot and Ankle Society hallux metatarsophalangeal-interphalangeal (AOFAS-MTP-IP) scale and a visual analogue scale (VAS). The hallux valgus angle (HVA), intermetatarsal angle (IMA), and distal metatarsal articular angle (DMAA) were measured before, after surgery, and at the six months follow-up. Results: The AOFAS-MTP-IP scale and VAS points were improved in both groups, with no significant difference between them. At the six-month follow-up, HVA, IMA, and DMAA were similar. Bone union was confirmed in both groups, and there were no significant major complications in both groups. Four people in the Ti screw group underwent implant removal surgery. Conclusion: Bioabsorbable Mg screws showed comparable clinical, radiologic results to Ti standard screws six months after distal modified chevron osteotomy. These screws are an alternative fixation material that can be used safely and avoid the need for implant removal operations.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.31 no.2
• /
• pp.127-135
• /
• 2009

Objectives : The titanium fixation system has been used in orthognathic surgery for fixation of bone segments usually, but the biodegradable fixation system was developed and also being used. The strongest point in the biodegradable system is that no extra operation should be needed to remove fixation materials. In spite of this merit, oral & maxillofacial surgeons hesitate to use this system in fracture or orthognathic surgery. In this study, as we got some clinical experiences, we'd like to report the result of clinical study using the biodegradable fixation system in orthognathic surgery. Patients and Methods : A total of 35 patients composed of 17 males and 18 females with 25 osteotomies in maxilla and 34 osteotomies in mandible were fixated with the biodegradable fixation system(Inion $CPS^{(R)}$). We investigated methods of stabilization, fixation time, and complications on the basis of the method as above. Results : Four 2mm thick L shaped plates with 7 holes of which 1 hole was removed were fixed in maxilla with six $2.0{\times}7mm$ screws. Three $2.5{\times}16{\sim}18mm$ screws were used to fix superior ramus area and one mandibular angle area in mandible. It took about 27.4 minutes in maxilla, 25.3 minutes in mandible to perform the fixation which took longer time than the titanium system(9.5 minutes in maxilla, 8 minutes in mandible). Generally, there was no problem except 9 cases in which there were some complications. Conclusions : In most cases, the biodegradable fixation system can be used without problem in usual orthognathic surgery. But, this system is inferior to the titanium fixation one in some respects such as fixation time, size, and physical property. Some supplementations for such weak points as aforementioned should be needed for the universal use of biodegradable materials.

• Journal of Korean Neurosurgical Society
• /
• v.42 no.4
• /
• pp.305-310
• /
• 2007

Objective : Combined antero-posterior fixation has been a standard method for bilateral interfacetal dislocation in cervical spine. The purpose of this study is to evaluate the efficacy and complication of anterior cervical stabilization in treatment of bilateral interfacetal dislocation. Methods : A total of 65 cases of traumatic bilateral interfacetal dislocation in cervical spine who were managed in our institution, from Mar. 1997 to Feb. 2006, were included in this study. Closed reduction was tried in all cases before operation. If closed reduction was accomplished successfully, only anterior cervical fixation was performed (Group I), and attempted to place screws bicortically as possible with unicortical screws. If failed, posterior open reduction with fixation was first tried, followed by anterior cervical fixation (Group II). All patients were evaluated for neurological outcome and radiological evidence of healing. Results : The Group I included 47 patients and the Group II, 18 patients. The improvement of Frankel grade and increase of mean cervical lordosis angles were not statistically different between two groups. Screw-plate system used did not influence the outcome. On follow up, solid bone fusion was evident and there were no cases of instability in both groups. Conclusion : Our study demonstrated that anterior cervical fixation on BID is safe and effective in comparison with combined antero-posterior cervical fixation.

• Proceedings of the KOSOMBE Conference
• /
• v.1998 no.11
• /
• pp.279-280
• /
• 1998

A new algorithm is developed that can reduce the metal artifact on CT caused by pedicle screws. Metal artifact has been recognized as a major problem in precise reading of CT images. In particular, spine surgeons have been bothered with the artifact appearing on CT taken after pedicle screw insertion. To reduce the artifact, our new algorithm first finds the center line from CT images, and then overlays an exact size screw image on the CT. The exact screw is obtained from an actual design specifications of screw, and the CT images are processed to maximize bone margins while minimizing screw images through adjusting the window width and level. 실험 결과 단순한 Window W/L 조절로는 해결되지 않는군요. This algorithm provides spine surgeons with more accurate CT images and thus better interpretation of CT to ascertain the success or failure of pedicle screw insertion.

• Journal of Veterinary Clinics
• /
• v.36 no.5
• /
• pp.292-295
• /
• 2019

A 2-year-old, 440 kg, thoroughbred gelding showed a lameness grade of 3 out of 5, as well as swelling and heating on the proximal interphalangeal joint (PIPJ). Periarticular new bones due to the arthritis were observed on performing radiography and ultrasonography. PIPJ arthrodesis was performed under general anesthesia. With the PIPJ open, the articular cartilage was removed by using curette, chisel, and mallet. Arthrodesis was performed with a PIP plate and two additional transarticular cortex screws inserted in lag fashion. A cast was placed over the limb distal from the proximal metatarsal bone. At 6 months after surgery, complete union of the PIPJ was confirmed by radiography, and the incision site was well closed. Based on the outcome, a PIP plate with two additional transarticular cortex screws inserted in lag fashion is recommended as a method for treating osteoarthritis of the PIPJ in horses.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.31 no.3
• /
• pp.207-215
• /
• 2009

Purpose: The aim of the present study is to evaluate the long term bone healing after horizontal ridge augmentation using auto block bone graft for implant installation timing. Materials and Methods: Five Beagle dogs(which were 14 months old and weighted approximately 10kg). In surgery 1(extraction & bone defect), premolars(P2, P3,P4) were extracted and the buccal bone plate was removed to create a horizontally defected ridge. After three months healing, in surgery 2(ridge augmentation). Auto block bone grafts from the mandibular ramus were used in filling the bone defects were fixed with stabilizing screws. The following fluorochrome labels were given intravenously to the beagle dogs: oxytetracycline 1week after the surgery, alizarin red 4 weeks after the surgery, calcein blue 8 weeks after the surgery. The tissue samples were obtained from the sacrificed dogs of 1, 4, 8, 12, 16 weeks after the surgery. Non-decalcified sections were prepared by resin embedding and microsection to find thickness of $10{\mu}m$ for the histologic examination and analysis. Results: 1. We could achieve the successful reconstruction of the horizontal bone defect by auto block bone graft. The grafted bone block remained stable morohologically after 16 weeks of the surgery. 2. In the histologic view. We observed osteoid tissue from the sample $4^{th}$ week sample and active capillary reconstruction in the grafted bone from the $12^{th}$ week sample. Healing procedures of auto bone grafts were compared to that of the host bone. 3. Bone mineralization could be detected from the $8^{th}$ week sample. 4. Fluorochrome labeling showed active bony changes and formation at the interface of the host bone and the block graft mainly. Bony activation in the grafted bone could be seen from the $4^{th}$ week samples. Conclusions: Active bone formation and remodeling between the grafted bone and host bone can be seen through the revascularization. After the perfect adhesion to host bone, Timing of successful implant installation can be detected through the ideal ridge formation by horizontal ridge augmentation.