• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.21 no.2
• /
• pp.149-165
• /
• 1999

The pathomechanism of obstructive sleep apnea(OSA) is not clearly elucidated. The possible mechanisms are pathologic reduction of pharyngeal muscular tonus during sleep, abnormal anatomical stenosis of nasopharyx or a combination of the above two mechanisms. It is very important to find the cause(anatomical location or pathologic dynamic change) of OSA in order to treat it. Cephalometric analysis in patients with obstructive sleep apnea is a good method for evaluating anatomical morphologic change but it cannot give any information about the dynamic changes occurring during sleep. On the contrary, nasopharyngeal endoscopy offer 3 dimensional image and information about the dynamic changes. Accordingly, these two diagnostic tools can be utilize in the diagnosis and treatment planning of OSA Cephalometric analysis of craniofacial skeletal and soft tissue morphology in 53 patients with OSA and 43 controls was performed and cephalometric analysis and nasopharygeal endoscopy were performed in 9 patients with OSA in order to come up with individualized therapy plans. Following results were obtained ; Patients with OSA showed 1. body weight gain 2. clockwise mandibular rotation 3. increased anterior lower facial height 4. inferiorly positioned hyoid bone 5. increased length of soft palate 6. decreased sagittal dimension of nasopharyx 7. increased vertical length of inferior collapsable nasopharyx 8. increased length of tongue Through cephalometric analysis and nasopharygeal endoscopy(mutually cooperative in diagnosis), 9. one can find the possible origin of OSA and make a adequate individualized therapy plan and predict accurate prognosis. Cephalometric analysis and nasopharygeal endoscopy are highly recommended as a diagnostic aid in OSA patients

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.13 no.3
• /
• pp.291-299
• /
• 1991

We retrospectively reviewed 334 inpatients who sustained a total of 518 mandibular fractures and who ewer treated in our department between l980-1990. This results were obtained as follows : 1. In respect of incidence, there were the highest frequency in July, and the lowest frequency in May. The number of patients has not been increased year after year due to competition with other department in our hospital. 2. The age frequency was the highest in the 2nd decade(38.9%) and the ratio of man to women was 4.9 : 1. 3. The most frequent cause of mandibular fracture was traffic accident(43.4%), and the next was fall down(24.3%), fist blow(71%), industrial accident(21%) and others in order. In the traffic accident, autobicycle accident was 14.1%. 4. The most common location of mandibular fracture was symphysis(38.8%), condyle(20.7% ), angle(19.9%) and body(15.1%) were next in order of frequency. The classification by location of fracture, the frequency of single fracture was 54.8%. 5. In 334 patients of mandibular fracture, the frequency of associated injuries was facial laceration(58.4%), teeth injuries(37.7%), extremity injuries(13.2%) were next in order of frequency. 6. The patients arrived in hospital immediately within 24 hours after accident wee 61.4% of all. In respect of treatment, open reduction was 68.7% of all. 7. Complications including infection were present 11.1% of patient. Other complications inclued delayed healing malocclusion, malocclusion and neurologic problem.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.31 no.2
• /
• pp.180-183
• /
• 2009

Eagle's syndrome refers to a symptomatic elongation of the styloid process or calcification of the stylohyoid and stylomandibular ligaments that usually accompanies facial and pharyngeal pain, dysphagia, and foreign-body sensation in the throat. Making an accurate diagnosis is difficult as Eagle's syndrome can be accompanied with referred pain to various areas of head and neck. Treatment options for Eagle's syndrome include non-surgical and surgical methods. The surest and the most effective method for relieving the symptom is surgical removal or reduction of the elongated styloid process. The present study reports two cases of female whom were diagnosed as "Eagle's syndrome" and whose chief complain was foreign-body sensation and pain in the throat on movement. Surgical removal via transoral approach of the elongated styloid process is a safe surgical option with favorable results compared to extraoral approach.

• Journal of the Korea Computer Graphics Society
• /
• v.3 no.2
• /
• pp.27-34
• /
• 1997

3-D image modeling is in high demand for automated visual inspection and non-destructive testing. It also can be useful in biomedical research, medical therapy, surgery planning, and simulation of critical surgery (i.e. cranio-facial). Image processing and image analysis are used to enhance and classify medical volumetric data. Analyzing medical volumetric data is very difficult In this paper, we propose a new image modeling method based on tetrahedrization to improve the visualization of three-dimensional medical volumetric data. In this method, the trivariate piecewise linear interpolation is applied through the constructed tetrahedral domain. Also, visualization methods including iso-surface, color contouring, and slicing are discussed. This method can be useful to the correct and speedy analysis of medical volumetric data, because it doesn't have the ambiguity problem of Marching Cubes algorithm and achieves the data reduction. We expect to compensate the degradation of an accuracy by using an adaptive sub-division of tetrahedrization based on least squares fitting.

• Journal of Dental Anesthesia and Pain Medicine
• /
• v.19 no.5
• /
• pp.253-260
• /
• 2019

Background: Sometimes general anesthesia is required for dental surgery in pregnant women. Facial bone fractures or neck abscess should be treated immediately. Dental surgery, however, creates a stressful situation that can cause inflammation. Inflammatory responses are a well-known major cause of preterm labor and preterm birth. Here we demonstrate the effects of remifentanil on the factors related to preterm labor and its mechanism of action on amniotic-derived epithelial cells (WISH cells). Methods: WISH cells were exposed to lipopolysaccharide (LPS) for 24 h and co-treated with various concentrations of remifentanil. MTT assays were performed to measure cell viability. To explain the effects of remifentanil on the factors related to inflammation in WISH cells, activation of nuclear factor kappa B ($NF-{\kappa}B$) and p38 and the expression of interleukin $(IL)-1{\beta}$, tumor necrosis factor $(TNF)-{\alpha}$, cyclooxygenase (COX)2, and prostaglandin E $(PGE)_2$ were quantified using western blotting and RT-PCR, respectively. Results: Remifentanil did not affect WISH cell viability. In western blot analysis, co-treatment with remifentanil resulted in decreased phosphorylation of $NF-{\kappa}B$, and expression of COX2 and $PGE_2$ in LPS-induced inflammation, but the results were statistically significant only at low concentrations. Reduction of $IL-1{\beta}$ and $TNF-{\alpha}$ expression was also observed with RT-PCR. Conclusion: Co-treatment with remifentanil does not affect the viability of WISH cells, but reduces the expression of the factors related to inflammation, which can induce uterine contraction and preterm labor. These findings provide evidence that remifentanil may inhibit uterine contraction and preterm labor in clinical settings.

• Archives of Craniofacial Surgery
• /
• v.20 no.2
• /
• pp.94-100
• /
• 2019

Background: Skin defects of head and neck need reconstruction using various local flaps. In some cases, surgeons should consider skin graft for large skin defect. It is important to heal skin graft and donor sites. The authors investigated wound healing mechanisms at the donor sites with split-thick-ness skin graft (STSG). In this study, the authors compared two types of immediate regraft including sheets and islands for the donor site after facial skin graft using remnant skin. Methods: The author reviewed 10 patients who underwent STSG, from March 2015 to May 2017, for skin defects in the craniofacial area. The donor site was immediately covered with the two types using remnant skin after harvesting skin onto the recipient site. Depending on the size of the remnant skin, we conducted regraft with the single sheet (n= 5) and island types (n= 5). Results: On postoperative day 1 and 3 months, the scar formation was evaluated using the Patient and Observer Scar Assessment Scale (POSAS) and Vancouver Scar Scale (VSS). Total POSAS and VSS scores for the island type were lower than in single sheet group after 3 months postoperatively. There was significant difference in specific categories of POSAS and VSS. Conclusion: This study showed a reduction in scar formation following immediate regrafting of the remnant skin at the donor site after STSG surgery. Particularly, the island type is useful for clinical application to facilitate healing of donor sites with STSG.

• The Journal of Advanced Prosthodontics
• /
• v.14 no.5
• /
• pp.273-284
• /
• 2022

PURPOSE. Computer-aided design and manufacturing (CAD-CAM) of implant abutments has been shown to result in surface contamination from site-specific milling and fabrication processes. If not removed, these contaminants can have a potentially adverse effect and may trigger inflammatory responses of the peri-implant tissues. The aim of the present study was to evaluate the bacterial disinfection and cleaning efficacy of ultrasonic reprocessing in approved disinfectants to reduce the microbial load of CAD-CAM abutments. MATERIALS AND METHODS. Four different types of custom implant abutments (total N = 32) with eight specimens in each test group (type I to IV) were CAD-CAM manufactured. In two separate contamination experiments, specimens were contaminated with heparinized sheep blood alone and with heparinized sheep blood and the test bacterium Enterococcus faecium. Abutments in the test group were processed according to a three-stage ultrasonic protocol and assessed qualitatively and quantitatively by determination of residual protein. Ultrasonicated specimens contaminated with sheep blood and E. faecium were additionally eluted and the dilutions were incubated on agar plates for seven days. The determined bacterial counts were expressed as colony-forming units (CFU). RESULTS. Ultrasonic reprocessing resulted in a substantial decrease in residual bacterial protein to less than 80 ㎍ and a reduction in microbiota of more than 7 log levels of CFU for all abutment types, exceeding the effect required for disinfection. CONCLUSION. A three-stage ultrasonic cleaning and disinfection protocol results in effective bacterial decontamination. The procedure is reproducible and complies with the standardized reprocessing and disinfection specifications for one- or two-piece CAD-CAM implant abutments.

• Imaging Science in Dentistry
• /
• v.53 no.1
• /
• pp.69-75
• /
• 2023

Purpose: Maxillofacial trauma predominantly affects young adults between 20 and 40 years of age. Although radioprotection is a legal requirement, the significant potential of dose reduction in computed tomography (CT) is still underused in the clinical routine. The objective of this study was to evaluate whether maxillofacial fractures can be reliably detected and classified using ultra-low-dose CT. Materials and Methods: CT images of 123 clinical cases with maxillofacial fractures were classified by two readers using the AOCOIAC software and compared with the corresponding results from post-treatment images. In group 1, consisting of 97 patients with isolated facial trauma, pre-treatment CT images at different dose levels (volumetric computed tomography dose index: ultra-low dose, 2.6 mGy; low dose, <10 mGy; and regular dose, <20 mGy) were compared with post-treatment cone-beam computed tomography (CBCT). In group 2, consisting of 31 patients with complex midface fractures, pre-treatment shock room CT images were compared with post-treatment CT at different dose levels or CBCT. All images were presented in random order and classified by 2 readers blinded to the clinical results. All cases with an unequal classification were re-evaluated. Results: In both groups, ultra-low-dose CT had no clinically relevant effect on fracture classification. Fourteen cases in group 2 showed minor differences in the classification code, which were no longer obvious after comparing the images directly to each other. Conclusion: Ultra-low-dose CT images allowed the correct diagnosis and classification of maxillofacial fractures. These results might lead to a substantial reconsideration of current reference dose levels.

• The korean journal of orthodontics
• /
• v.40 no.1
• /
• pp.16-26
• /
• 2010

Objective: The purposes of this study were to evaluate the force and stress depending on the type, deflection and thickness of the materials and to evaluate the mechanical properties of thermoplastic materials after repeated loading. Methods: Four types of thermoplastic products were tested. Force until the deflections of 2.0 mm and the stress when the materials were restoring to its resting position were evaluated. The mechanical properties of thermoplastic materials evaluated after 5 repeated loading cycles. Results: The interaction was observed between the thickness and the deflection (p < 0.05) from the regression equation. Thickness and amount of deflection rather than products and materials showed the largest effect on force and stress. In all products, at least 159 gf of force was required for more than 1.0 mm deflection or when materials with 1.0 mm thickness were deflected. The stress recorded was more than 19 gf/$mm^2$. During repeated loading, each group showed significant difference on the force and the stress (p < 0.01), 10 - 17% reduction of force and 4 - 7% reduction of stress in average. Conclusions: Proper thickness of thermoplastic materials and deflection level of tooth movement should be decided for the physiologic tooth movement. Force decay after repeated loading should be considered for the efficient tooth movement.

• Journal of Oral Medicine and Pain
• /
• v.32 no.3
• /
• pp.293-303
• /
• 2007

The purpose of this paper is to evaluate if there is a relationship between anterior disc displacement without reduction and development of anterior open bite, and a relation between occurrence of open bite and occlusal appliance therapy. In general, the statistically significant differences were found between the Group 1 and 2 and normal mean group. The variables that represent mandibular size and form, showed a statistical significance in all 3 groups. Also 3 groups patients had a smaller ANB, a larger FMA than normal mean group. When we compared the 3 groups with respect to all cephalometric measurements by One-way analysis of variance (ANOVA), group 1 and 2 patients had a larger FMA, a larger SN to mandibular plane angle, a larger maxillomandibular plane angle, a larger occlusal plane to mandibular plane angle, a smaller total posterior facial height/total anterior facial height(%), and a larger gonial angle than group 3. The statistically significant differences were not found between the Group 1 and 2, and skeletal patterns were similar. Thus, morphologic features of patients with vertical discrepancies may represent a risk factor for the development of anterior open bite with or without occlusal appliance treatment. In case of patients with vertical discrepancy, we may have to be more careful when inducing a change of the vertical dimension.