[Show abstract][Hide abstract] ABSTRACT: Purpose:
To evaluate the cumulative survival rate (CSR) and mechanical complications of single-tooth Ankylos® implants.
Materials and methods:
This was a retrospective clinical study that analyzed 450 single Ankylos® 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.
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).
The Ankylos® 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.
Preview · Article · Jan 2015 · The journal of advanced prosthodontics
[Show abstract][Hide abstract] ABSTRACT: Silk fibroin (SF) is a new degradable barrier membrane for guided bone regeneration (GBR) that can reduce the risk of pathogen transmission and the high costs associated with the use of collagen membranes. This study compared the efficacy of SF membranes on GBR with collagen membranes (Bio-Gide®) using a rat calvarial defect model.
Thirty-six male Sprague Dawley rats with two 5 mm-sized circular defects in the calvarial bone were prepared (n=72). The study groups were divided into a control group (no membrane) and two experimental groups (SF membrane and Bio-Gide®). Each group of 24 samples was subdivided at 2, 4, and 8 weeks after implantation. New bone formation was evaluated using microcomputerized tomography and histological examination.
Bone regeneration was observed in the SF and Bio-Gide®-treated groups to a greater extent than in the control group (mean volume of new bone was 5.49 ± 1.48 mm(3) at 8 weeks). There were different patterns of bone regeneration between the SF membrane and the Bio-Gide® samples. However, the absolute volume of new bone in the SF membrane-treated group was not significantly different from that in the collagen membrane-treated group at 8 weeks (8.75 ± 0.80 vs. 8.47 ± 0.75 mm(3), respectively, P=.592).
SF membranes successfully enhanced comparable volumes of bone regeneration in calvarial bone defects compared with collagen membranes. Considering the lower cost and lesser risk of infectious transmission from animal tissue, SF membranes are a viable alternative to collagen membranes for GBR.
Preview · Article · Dec 2014 · The journal of advanced prosthodontics
[Show abstract][Hide abstract] ABSTRACT: Pediatric patients are considered to be more radiosensitive than adults; thus, radiation dose evaluations based on radiologic examinations are particularly important in this population. However, no national diagnostic reference levels (DRLs) are available for pediatric patients in the Republic of Korea. Therefore, the aim of this study was to determine the usage of panoramic and cephalometric radiography under the National Health Insurance (NHI) scheme and to investigate the current DRLs for child panoramic and lateral cephalometric radiography using dose area product (DAP). DAP values were obtained for standard child exposure settings used routinely by dentists. Analysis was performed on data obtained from 28 panoramic and 20 cephalometric x-ray units for the DAP investigation. DRLs for child panoramic and cephalometric radiography were found to be 95.9 mGy cm and 121.3 mGy cm, respectively. These DRLs are higher than those recommended in the UK and Germany, which indicates that further effort is required to reduce pediatric doses in the Republic of Korea.
[Show abstract][Hide abstract] ABSTRACT: This study compared bone healing following the use of 2 piezoelectric surgery units or conventional mechanical cutting with carbide and diamond drills to explore their future applications for bone surgery.
Subcritical-size (approximately 1.5-2 mm) calvarial defects were created in the parietal bones of adult mice. Following defect standardization, a full-thickness semicircular defect was created on the parietal bones of 12 mice divided into 4 groups: carbide bur, Surgystar, diamond bur, and Piezoelectric System. Hard tissue healing was assessed using micro-computed tomography at 1 day, 2 weeks, 4 weeks, and 8 weeks after surgery.
At 4 weeks, the Surgystar group and Piezoelectric System group showed a significant difference from the carbide group. The Surgystar and Piezoelectric System groups did differ from the diamond group. At 8 weeks, the Surgystar and Piezoelectric System groups differed significantly from the carbide and diamond groups. The fraction of healing results over the 8 weeks demonstrated that the Surgystar group had a significantly higher bone healing percentage than did the carbide group (P = 0.001) and the diamond group (P = 0.026), but it did not differ significantly from the Piezoelectric System group (P = 0.420).
The Surgystar and Piezoelectric System are suitable for bone osteotomy and provide faster bone healing in comparison with mechanical instrumentation.
No preview · Article · Jan 2014 · The Journal of craniofacial surgery
[Show abstract][Hide abstract] ABSTRACT: The objective of this study was to demonstrate that a silk fibroin (SF) and 4-hexylresorcinol (4-HR) incorporation membrane could be used for a guided bone regeneration technique. Fourier transform infrared measurements were obtained to determine change of physical property of SF membrane by 4-HR incorporation. Two peri-implant defects, 3.0 × 5.0 mm (width × length), were prepared on the lateral side of the implant hole in the tibia of New Zealand white rabbits (n = 8). The peri-implant defect was left unfilled in the control group. Silk fibroin + 4-HR membrane was applied to the peri-implant defect in the experimental group. The 8 animals were killed at 8 weeks after implantation. Subsequently, removal torque test and histomorphometric evaluation were done. Fourier transform infrared spectroscopy showed no specific chemical interaction between 4-HR and SF. In the histomorphometric analysis, the mean bone regeneration was 18.3 ± 1.9 mm in the experimental group and 9.3 ± 0.9 mm in the control group (P = 0.004). In conclusion, the SF and 4-HR incorporation membrane successfully regenerated bone in the rabbit tibia peri-implant bone defect model.
No preview · Article · Nov 2013 · The Journal of craniofacial surgery
[Show abstract][Hide abstract] ABSTRACT: Changes in the condylar position after bilateral sagittal split ramus osteotomy (BSSO) can cause many complications, such as condylar dysfunction and increased risk of relapse. This study evaluated a simple approach for condylar repositioning in BSSO as a method to rapidly obtain the patient's centric relation (CR) bite position without prefabricated equipment.
The study subjects included 9 patients (5 men and 4 women; mean age, 23.7 years) who underwent BSSO in the Department of Oral and Maxillofacial Surgery in Hallym University hospital between December 2009 and March 2012. We performed BSSO with the condylar-repositioning method according to the patient's CR bite.
Measurements of changes in the condylar position via radiographic images (lateral cephalometric radiographs) did not indicate significant differences after surgery (P < 0.05). In surveys of temporomandibular joint symptoms, the scores for categories (sound, pain, mouth opening limitation) also did not show any increases after surgery.
Within a standard operating time, the condyle was effectively repositioned using the condylar-repositioning method described in this study. These results indicate this new repositioning method is simple and eliminates the need for any additional device.
No preview · Article · Sep 2013 · The Journal of craniofacial surgery
[Show abstract][Hide abstract] ABSTRACT: A novel maxillomandibular fixation (MMF) procedure using a skeletal anchorage screw (SAS) (in the maxilla) and an arch bar (in the mandible), which we call "hybrid maxillomandibular fixation," was explored in this study. The aims of the study were to examine the efficacy of our hybrid MMF method and to compare periodontal tissue health and occlusal rehabilitation among 3 MMF methods.
In total, 112 patients who had undergone open reduction at the Department of Oral and Maxillofacial Surgery between September 2005 and December 2012 were selected for this study. The participants were assigned to one of the following groups: SAS (maxilla), SAS (mandible), SAS-arch bar, or arch bar-arch bar. Periodontal health was evaluated using the Gingival Index, and the perioperative occlusal reproducibility was evaluated using a score of 1 to 3. Statistical analysis was performed using parametric tests (Student t test or 1-way analysis of variance followed by post hoc Tukey test).
In the Gingival Index comparison performed 1 month after the surgery, only the group using the arch bars and wiring was significantly different from the other groups (P < 0.05). The occlusal reproducibility scores were not significantly different. The pain and discomfort of the patients were reduced in the hybrid MMF group.
The hybrid MMF takes advantage of MMF using both arch bars and SASs for mandibular fractures. In addition, it overcomes many problems presented by previous MMF methods.
No preview · Article · Sep 2013 · The Journal of craniofacial surgery
[Show abstract][Hide abstract] ABSTRACT: The purpose of this study was to evaluate displacement of the mandibular condyle after orthognathic surgery using a condylar-repositioning device.
The patient group comprised 20 adults who underwent bimaxillary surgery between August 2008 and July 2011. The degree of condylar displacement was measured by pre- and postoperative tomographic analysis using centric relation bite and a wire during surgery. A survey assessing temporomandibular joint (TMJ) sound, pain, and locking was performed. The 20 tomographs and surveys were analyzed using the Wilcoxon signed-rank test and McNemar's test, respectively.
No significant changes were observed in the anterior, superior, or posterior joint space of the TMJ (p > 0.05). In addition, no significant change was observed in TMJ sound (p > 0.05). However, TMJ pain and locking both decreased significantly after surgery (p < 0.05).
Due to its simplicity, this method may be feasible and useful for repositioning condyles.
Preview · Article · Apr 2013 · Korean Journal of Orthodontics
[Show abstract][Hide abstract] ABSTRACT: Purpose: Intravenous sedation with midazolam is common in contemporary dentistry. That is effective for anxious patients, but additional analgesic agent needs to be used, because midazolam alone doesn't have an analgesic effect. This study was performed to select an analgesic agent between an opioid agent, and nonsteroidal anti-inflammatory drugs as adjunctives in intravenous sedation with midazolam. Methods: The subjects were 60 patients who visited the Department of Oral and Maxillofacial Surgery, Sacred Heart Hospital, Hallym University, between August 2009 and February 2010. Conscious sedation was performed on 20 patients of 3 groups (control group, ketorolac group, and fentanyl group), who were divided randomly. The analgesic agent was administrated preoperatively. For sedation, vital signs were recorded. After sedation and operation, subjective questionnaires of the patient and operator were implemented. Results: All of the , blood pressure, and heart rates stayed within the normal range for sedation. The sedation depth and analgesic effect of the ketorolac group and fentanyl group were similar. In the case of sedation depth, 12 patients in the ketorolac group and 14 patients in the fentanyl group had no memory of surgery. In the case of analgesic effect, the visual analogue scale of pain scored 2~3 in 13 patients in the ketorolac group, and 0~2 in 12 patients in the fentanyl group. The satisfaction of patients and doctors was also similar. Conclusion: Considering the management and complication of an opioid agent, non-steroidal anti-inflammatory drugs is more effective than an opioid agent.
[Show abstract][Hide abstract] ABSTRACT: Cystic lesions on the jaws with expansion can invade the adjacent anatomical structure, infiltrate and expand the jaws, cause facial deformity, etc. There is great potential for pathologic fractures after cyst enucleation, and damage to the major structures like the nerve, artery. For these reasons, marsupialization and decompression are commonly used to reduce the cystic size. In 1947, Thomas first mentioned decompression that reduces the osmotic pressure in a cyst by making a hole in the cyst and insert a drain. In our cases, a large sized cystic lesion was treated with a specific device made from an orthodontic band and spinal needle. This device is easy and effective for applications and self irrigation.
[Show abstract][Hide abstract] ABSTRACT: Introduction: In today's society, the rapid and appropriate care of the dental emergency patients is much more important. So, a retrospective study on the characteristics of emergency dental injuries and diseases will be very meaningful. Materials and Methods: This retrospective clinical study was carried by reviewing the radiographic films and emergency chart of 11,493 patients who had visited the emergency room of Hallym Sacred heart Hospital and were treated in the Department of Oral and Maxillofacial Surgery from January 2006 to December 2010. Results: The male to female ratio was 1.9:1. The highest monthly incidence was observed in May (10.4%) and June (8.9%) and the peak age distribution was the first decade (56.0%), followed by the second decade (16.0%). Trauma was the most common cause in dental emergency patients, followed in order by toothache, odontogenic infection, temporomandibular joint (TMJ) disorder and oral hemorrhage. Soft tissue injury was most prevalent in the trauma group, followed by tooth injury and facial bone fractures. In the tooth injury group, tooth fracture (56.7%) showed the highest incidence followed in order by tooth subluxation (18.2%), tooth concussion (16.9%), tooth avulsion (11.5%) and alveolar bone fractures (3.7%). In the facial bone fracture group, mandibular fractures (81.8%) showed the highest incidence followed in order by maxilla fractures (15.7%), nasal bone fractures (9.0%), zygomaticomaxillary complex fractures (5.4%), orbital bone fractures (2.5%). In mandibular bone fractures, the most common location was the symphysis (70.1%), followed in order by the mandibular angle (33.0%), mandibular condyle (22.8%) and mandibular body (13.6%). In the infection group, a submandibular space abscess (46.2%) was most common followed in order by a buccal space abscess (17.4%), canine space abscess (16.9%) and submental space abscess (12.3%). TMJ dislocation (89.3%) showed the highest incidence in the TMJ disorder group, followed by TMJ derangement (10.7%). In the other group, a range of specific symptoms due to post operation complications, trigeminal neuralgia, chemical burns and foreign body aspiration were reported. Conclusion: For the rapid and appropriate care of the dental emergency patients, well-organized system should be presented in oral and maxillofacial surgery. And it is possible under analysis of pattern and the variation of the dental emergency patients.
[Show abstract][Hide abstract] ABSTRACT: The placement of a single miniplate is not sufficient to achieve rigid fixation in mandibular angle fractures. It often causes difficulties in reducing the intermaxillary fixation (IMF) period. Consequently, the placement of 2 miniplates is preferable. The intraoral approach in an open reduction and internal fixation (ORIF) of a mandibular angle fracture with 2 miniplates is often challenging. Accordingly, an alternative of transbuccal approach is performed. However, this method leaves a scar on the face and can result in facial nerve injury. This clinical study suggests a protocol that can maintain rigid fixation without a transbuccal approach in mandibular angle fractures.
[Show abstract][Hide abstract] ABSTRACT: Bone morphogenic protein-4 (BMP-4) is widely expressed in oral cavity and involved in tooth morphogenesis, cellular differentiation and proliferation. The purpose of this study was to compare the difference in expression pattern of BMP-4 in odontogenic keratocysts (OKC) and dentigerous cysts (DC).
We evaluated 77 cysts, OKC (n = 34) or DC (n = 43). The average age of patients with OKC was 29.5 +/- 14.4 and that of patients with DC was 36.1 +/- 19.4. The male to female ratio was 20:14 for OKC and 27:16 for DC. Ten cases of OKC were recurrences. Expression of BMP-4 was determined by immunohistochemistry and in situ hybridization.
The intensity scales were (-) for invisible or trace staining, (+) for visible staining, and (++) for dense, strong staining. OKCs exhibited the following staining patterns: the epithelium in 15/34 specimens and the mesenchymal cells in 17/34 specimens showed (++) stain. In contrast, the staining pattern of DC was (-) for epithelium in 37/43 specimens. The mesenchymal cells showed (-) degree staining in 30/43 specimens. The difference between the groups studied was significant (P < 0.001 in epithelium and mesenchymal cells). When recurrent and non-recurrent OKC were compared BMP-4 was expressed more intensely in the recurrent cases (P = 0.036 in epithelium). The difference in BMP-4 expression in mesenchymal cells was not significant. In situ hybridization demonstrated positive mRNA probes to BMP-4 were localized in epithelium and mesenchymal cells of OKCs and DCs.
BMP-4 was expressed more intensely in OKC when compared with DC, and was more intensely expressed in recurrent cases.
Full-text · Article · Apr 2005 · Journal of Oral Pathology and Medicine