• Imaging Science in Dentistry
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• v.53 no.4
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• pp.283-289
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• 2023

The apnea-hypopnea index is widely regarded as a measure of the severity of obstructive sleep apnea (OSA), a condition characterized by recurrent episodes of apnea or hypopnea during sleep that induce airway collapse. OSA is a catastrophic problem due to the wide range of health issues it can cause, including cardiovascular disease and memory loss. This review was conducted to clarify the roles of various imaging modalities, particularly cone-beam computed tomography (CBCT), in the diagnosis of and preoperative planning for OSA. Unfortunately, 2-dimensional imaging techniques yield insufficient data for a comprehensive diagnosis, given the complex anatomy of the airway. Three-dimensional (3D) imaging is favored as it more accurately represents the patient's airway structure. Although computed tomography and magnetic resonance imaging can depict the actual 3D airway architecture, their use is limited by factors such as high radiation dose and noise associated with the scans. This review indicates that CBCT is a low-radiation imaging technique that can be used to incidentally identify patients with OSA, thereby facilitating early referral and ultimately enhancing the accuracy of surgical outcome predictions.

• Journal of radiological science and technology
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• v.39 no.4
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• pp.543-547
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• 2016

Acute stroke is a one of common disease that require fast diagnosis and treatment to save patients life. however, the acute stroke may cause lifelong disability due to brain damage with no prompt surgical procedure. In order to diagnose the Stroke, brain perfusion CT examination and possible rapid implementation of 3D angiography has been widely used. However, a low-dose technique should be applied for the examination since a lot of radiation exposure to the patient may cause secondary damage for the patients. Therefore, the degradation of the measured CT images may interferes with a clinical check in that blood vessel shapes on the CT image are significantly affected by gaussian noise. In this study, we employed the spatio-temporal technique to analyze dynamic (brain perfusion) CT data to improve an image quality for successful clinical diagnosis. As a results, proposed technique could remove gaussian noise successfully, demonstrated a possibility of new image segmentation technique for CT angiography. Qualitative evaluation was conducted by skilled radiological technologists, indicated significant quality improvement of dynamic CT images. the proposed technique will be useful tools as a clinical application for brain perfusion CT examination.

• Journal of Oral Medicine and Pain
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• v.38 no.1
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• pp.77-86
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• 2013

In order to evaluate the effect of conservative treatment for Temporomandibular Disorders(TMD), 137 patients were subjected at the Department of Oral Medicine, Pusan National University Dental Hospital from June 2012 to Sept. 2012. They were treated conservatively with behavioral therapy, physical therapy, medication and occlusal stabilizing splint therapy. Subjective symptoms and clinical findings were investigated to evaluate and compare the patients' status after 3 months treatment. The results were as follows; 1. Pain, Noise, LOM(Limitation of motion) and MCO(Maximum comfortable opening) measurements of TMD were markedly improved after conservative treatments including behavior therapy, physical therapy, medication and splint therapy. 2. There was no difference in treatment outcomes after conservative treatments when the subjects were classified and compared according to gender and chronicity. 3. Conservative treatment including stabilization splint produced better results than physical therapy with medication. 4. After 3 months of treatment, pain and LOM were significantly improved in the MD(Muscle disorder) group. Pain, LOM and noise were significantly improved in the DD(Disc displacements) group. In the OA(Osteoarthritis) group, pain, noise, LOM and MCO were significantly improved.

• Journal of Oral Medicine and Pain
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• v.38 no.1
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• pp.69-76
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• 2013

Aim : The purpose of this study was to investigate the hypothesis that treatment with self-checking behavior management program was valuable in the management of temporomandibular disorders compared with a existing method treatment group. Methods : All participants who are diagnosed with temporomandibular disorders were treated with medication and physical therapy. They came into the clinic at intervals of two weeks, three times. The signs and symptoms were assessed investigating Pain NRS(Numerical Rating Scale), MCO(Maximum comfortable opening), Noise NRS, LOM(Limitation of Mouth opening) NRS at every visit. Experimental group received instructions repeatedly by using self evaluation questionnaire. Control group was educated once at the beginning of treatment. The difference Pain NRS, MCO, Noise NRS, LOM NRS between first and second visits, first and third visits were estimated.. Result :Experimental group showed greater improvement on MCO difference after stopping medication(p=0.001). This improvements were prominent in the male(p=0.001) and the first or second decade of the patients(p=0.004). Conclusion : The present study showed that there was better result when educating repeatedly with using self evaluation questionnaire than educating once at the beginning of the treatment.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.4
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• pp.558-563
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• 2000

The lasers have been used in dentistry for more than 30 years and the application of lasers for drilling dental hard tissue has been investigated since the early developement of lasers. Recently, the Er:YAG laser was invented for hard tissue ablation. The Er:YAG laser, having a wavelength of 2.94um, is highly absorbed in both water and hydroxiapatite, leading to a very effective material for hard tissue removal by bursting off the solid tissue component that is, enamel and dentin are removed by the Er :YAG laser by water vaporization and microexplosion, without any melting of inorganic tissues. Therefore, the Er:YAG laser produced round craters with well defined margins and the surrounding tissues had no cracks and no charring. When used for cavity preparation, pulpal damage should not occur if hear buildup is minimized by careful selection of exposure parameters and by use of a water spray. The present study demonstrated that the Er:YAG laser cut the tooth substance adequately for composite resin restoration, without having undesirable side effects such as harmful effects on the pulp, discoloration or cracking etc. Also, the child patients were well cooperative during laser treatment mainly because of little noise, lesser vibration and minimal pain compared to conventional means of cavity preparation.

• Journal of Oral Medicine and Pain
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• v.41 no.4
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• pp.169-179
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• 2016

Purpose: This study is designed to analyse etiology and bone pattern at the first visit using cone-beam computed tomography (CBCT) and to evaluate the treatment outcome of conservative treatment in temporomandibular disorder (TMD) patients with rheumatoid arthritis (RA). Methods: One hundred condyles in 50 subjects with RA were chosen among the patients who presented to the Department of Oral Medicine of Pusan National University Dental Hospital, diagnosed as TMD. Condylar bone changes were classified by normal, erosive bony change, proliferative bony change and combined group (erosive bony change+proliferative bony change). They were treated conservatively with physical therapy, medication, behavioral therapy and/or occlusal stabilizing splint therapy. After 3 months on average, patients were re-evaluated with regards to subjective symptoms and the clinical findings were investigated. Results: TMD patients with RA have behavioral contributing factors such as parafunctional habit. The results that analyse bone pattern at the first visit using CBCT proliferative bony changes group (32.6%) were more common than erosive bony changes group (15.2%). In comparison between unilateral and bilateral bony change in temporomandibular joint, the ratio showed no significant differences. After 3 months of conservative treatments, pain, noise, limitation of motion (LOM) were markedly improved regardless of occlusal splint therapy. However only LOM was significantly improved through occlusal splint therapy during 3 months. Conclusions: TMD patients with RA had similar behavioral contributing factors and characteristics of CBCT images shown in general TMD patients and also similar response to conservative treatment so it is difficult to differentiate. Therefore when TMD patients show symptoms corresponding to clinical diagnostic criteria of RA at the first visit, serological testing should be conducted and through this, early diagnosis and treatment of RA should be initiated.

• Imaging Science in Dentistry
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• v.31 no.2
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• pp.93-99
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• 2001

Purpose: To analyze the possible association between magnetic resonance imaging signal intensity of temporomandibular joint disk and posterior attachment, and the type and extent of disk displacement, disk configuration, effusion and clinical signs in patients with internal derangement. Materials and Methods: Magnetic resonance images of the 132 temporomandibular joints of 66 patients with temporomandibular joint displacement were analyzed. The clinical findings were obtained by retrospective review of the patients' records. The type and extent of disk displacement, disk configuration and effusion were evaluated on the proton density MR images. The signal intensity from the anterior band, posterior band and posterior attachment were measured on MR images. The associations between the type and extent of disk displacement, disk configuration, effusion and clinical signs and the MR signal intensity of disk and posterior attachment were statistically analyzed by student's t-test. Results: Of 132 joints, 87 (65.9%) showed anterior disk displacement with reduction (ADR) and 45 (34.1%) showed anterior disk displacement without reduction (ADnR). The signals from posterior attachments were lower in joints with ADnR than those of ADR (p<0.05). The results showed statistically significant (p<0.05) association between the type and extent of disk displacement and disk configuration, and decreased signal intensity of posterior attachment. There were no statistical associations between pain, noise and limited mouth opening, and signal intensity of disk and posterior attachment. Conclusions: The average signal from posterior attachment was lower in joints with ADnR than that of ADR. The type and extent of disk displacement and disk configuration appeared to be correlated with the signal intensity from posterior attachment.

• Journal of Oral Medicine and Pain
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• v.38 no.3
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• pp.275-289
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• 2013

This study was conducted to investigate and analyze the dental patients' awareness and understanding about TMDs. Among the total number of 243 patients who had visited the department of dentistry of Busan Paik Hospital, Inje University or Hanvit dental hospital in Ulsan metropolitan city and participated in the survey, 195 patients who filled in all parts of the questionnaire were selected as the subjects. The results were as follows. 1. The subjects who were aware of the term, "TMDs" were 17.4%. The group with total education period of 12 years and over was significantly more aware of "TMD"(82.4%, p<0.01) than the other group. The subjects who were aware of the term, "jaw joint disease" were 81.0%. 30 to 49 age group(45.6%, p<0.05) and the group with total education period of 12 years and over(60.1%, p<0.01) were significantly more aware of "jaw joint disease" than other groups. 2. More than half of the subjects chose "overuse of the jaws" as the concept of jaw joint disease(50.6%). 3. TV, radio(41.4%) was the most frequent source of awareness about jaw joint disease followed by family and friends(20.2%), hospitals and health professionals(18.2%), internet(15.7%) and newspapers, magazines(4.5%). Among the respondents who were aware of jaw joint disease through TV, radio, 30 to 49 age group showed significantly higher percentage(52.4%, p<0.05) than other age groups. Among the respondents who were aware of jaw joint disease through internet, 18 to 29 age group showed significantly higher percentage(61.3%, p<0.01) than other age groups. Among the respondents who were aware of jaw joint disease from hospitals and health professionals, the group with total education period of 12 years and over showed significantly higher percentage(75.0%, p<0.05) than the other group. 4. Noise during mouth opening and closing(26.9%), mouth opening difficulty(25.1%) and jaw pain(13.7%) were the most frequently responded sign and symptoms of jaw joint disease. For the causes of jaw joint disease, enjoying hard food chewing(19.5%), occlusal discrepancy(19.0%) and chewing with one side only(18.5%) were responded in sequence. TMJ surgery(28%) was the most frequently responded treatment method for jaw joint disease, followed by occlusal appliance therapy(23.9%) and physical therapy(14.6%). For preventive method of jaw joint disease, avoid eating hard food(21.1%), avoid opening mouth wide(17.0%) and simultaneous using of molar of both side when chewing food(15.4%) were chosen frequently.

• Science of Emotion and Sensibility
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• v.14 no.4
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• pp.545-554
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• 2011

In this study, the parameters of Polysomnography (PSG) test, such as total sleep time, snoring time, had been analyzed to evaluate the effectiveness of a developed anti-snore pillow. The developed anti-snore pillow is made up of two polyvinylidene fluoride (PVDF) vibration sensors, pumps, valves, and air bladders. The two PVDF sensors inside the pillow can acquire the sound signals and the algorithm was perfectly designed to extract snoring by removing unwanted noise accurately and automatically. Once the pillow recognizes snore, a pump inside the hardware activates, and a bladder under the neck area inside the pillow will be inflated. The PSG test was used and two volunteers were participated for the study. The parameters of the PSG results were analyzed to evaluate the effectiveness of the anti-snore pillow. The total sleep time of each volunteer was similar on each phase of test, but the snoring time and the longest snoring episode were significantly decreased with the use of anti-snore pillow. The overall results showed excellent possibilities for reducing snoring for the person who snores during sleep by using the anti-snore pillow. The effectiveness of the anti-snore pillow can be evaluated by the PSG test. Moreover, the relationship between each parameter of PSG test and the quality of sleep will be used for further researches.

• Journal of the Korean Society of Radiology
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• v.13 no.4
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• pp.581-588
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• 2019

MRI is superior when contrasted to help the organization generate artifacts resolution, but also affect the diagnosis and create a image that can not be read. Metal is inserted into the tooth, it is necessary to often be inhibited in imaging by causing the geometric distortion due to the majority and if the difference between the magnetic susceptibility of a ferromagnetic material or paramagnetic reducing them. The purpose of this study is to conduct a metal artefact in accordance with the analysis using a diamagnetic material. The magnetic material include a wire for the orthodontic bracket and a stainless steel was used as a diamagnetic material was used copper, zinc, bismuth. Testing equipment is sequenced using 1.5T, 3T was used was measured using a SE, TSE, GE, EPI. A self-produced phantom material was used for agarose gel (10%) to a uniform signal artifacts causing materials are stainless steel were tested by placing in the center of the phantom and cover inspection of the positive cube diamagnetic material of 10mm each length.After a measurement artefact artifact zone settings area was calculated using the Wand tool After setting the Low Threshold value of 10 in the image obtained by subtracting images, including magnetic material from a pure tool phantom images using Image J. Metal artifacts occur in stainless steel metal artifact reduction was greatest in the image with the bismuth diamagnetic materials of copper and zinc is slightly reduced, but the difference in degree will not greater. The reason for this is thought to be due to hayeotgi offset most of the susceptibility in bismuth diamagnetic susceptibility of most small ferromagnetic. Most came with less artifacts in image of bismuth in both 1.5T and 3T. Sequence-specific artifact reduction was most reduced artifacts from the TSE 1.5T 3T was reduced in the most artifacts from SE. Signal-to-noise ratio was the lowest SNR is low, appears in the implant, the 1.5T was the Implant + Bi Cu and Zn showed similar results to each other. Therefore, the results of artifacts variation of diamagnetic material, magnetic susceptibility (${\chi}$) is the most this shows the reduced aspect lower than the implant artificial metal artifacts criteria in the video using low bismuth susceptibility to low material the more metal artifacts It was found that the decrease. Therefore, based on the study on the increase, the metal artifacts reduction for the whole, as well as dental prosthesis future orthodontic materials in a way that can even reduce the artifact does not appear which has been pointed out as a disadvantage of the solutions of conventional metal artifact It is considered to be material.