• Korean Journal of Biological Psychiatry
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• v.4 no.2
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• pp.246-250
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• 1997

Tardive dyskinesia(TD) is a serious side effect of long-term treatment with neuroleptic medications. To investigate if glutamatergic hyperfunction is associated with TD, effect of MK-801 on the prevention and treatment of TD was studied using a rat model, ie, vacuous chewing movements(VCM). When comparing VCM scores of GroupI(haldol decanoate+MK-801) with that of GroupII(haldol decanoate+phosphate buffer saline), late measured VCM scores of former were significantly lower than that of latter, meaning that MK-801 is effective in the prevention of VCM. Furthermore, when MK-801(0.1mg/kg, 0.3mg/kg) is administered to VCM(+) rats(VCM${\geq}$ 7/4min) of GroupII, VCM scores were significantly decreased, meaning that MK-801 is also effective in the treatment of VCM. From the above results, it is suggested that glutamatergic hyperfunction might be involved in the development of TD and MK-801 could be effective in the prevention and treatment of it.

• Journal of the Korea Convergence Society
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• v.2 no.4
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• pp.39-45
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• 2011

This paper examined the relationship between stress, the most potential cause among a variety of factors causing temporomandibular joint disorder, and temporomandibular joint disorder. In particular, this paper aimed to identify the temporomandibular joint disorder of those who were in their 20s, the age when temporomandibular joint disorder possibility increased. The survey was conducted by randomly selecting 120 college students who understood the purposes of this research and agreed to the survey from July 11 to 30, 2011. For the general features of the subjects, only gender showed any statistically significant difference. In the relationship between stress and habits related to temporomandibular joint disorder, the habit which the subjects had the most was "propping up of the chin", 64.4%. Five habits were observed the most frequently in the group with the highest stress. The habit of chewing on one side of the mouth showed the highest response as 81.5% in the group with high stress. Other habits showed similar results, about 60%.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.2
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• pp.148-155
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• 2008

The aim of the study is to interpret the distribution of occlusal force by 3-dimensional finite element analysis of ISP(Implant Supported Prosthesis) supported by minimum number of implant to restore the edentulous patients. For this study, the Astra Tech implant system is used. Geometric modeling for 6 and 4 fixture ISP group is performed with respect to the bone, implant and one piece superstructure, respectively. Implants are arbitrarily placed according to the anatomical limit of lower jaw and for the favorable distribution of occlusal force, which is applied at the end of cantilever extension of ISP with 30mm. Element type is tetrahedral for finite element model and the typical mechanical properties, Young's modulus and Poisson's ratio of each material, cortical, cancellous bone and implant material are utilized for the finite element analysis. From this study, we can see the distribution of equivalent stress equal to real situation and speculate the difference in the stress distribution in the whole model and at each implant fixture, From the analysis, the area of maximum stress is distributed on distal contact area between bone and fixture in the crestal bone. The maximum stress is 53MPa at the 0.2mm area from the bone-implant interface in the maximum side for 300N load condition for 4 fixture case, which is slightly less than the stress calculated from allowable strain. This stress has not been deduced to directly cause the loss of crestal bone around implant fixture, but the stress can be much reduced as the old peoples may have lower chewing force. Thus, clinical trial may be performed with this treatment protocol to use 4 fixtured ISP for old patients.

• The Korean Journal of Pain
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• v.27 no.3
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• pp.260-265
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• 2014

Background: To evaluate the results of conventional radiofrequency thermorhizotomy (CRT) for trigeminal neuralgia (TN) in patients with failed medical management. Methods: Patients with Trigeminal neuralgia who were referred to us for 'limited intervention' during the time frame July-2011 to Jan-2013 were enrolled for this study. CRT was administered by the Sweet technique. Pain relief was evaluated by the principle investigator. Results: Eighteen patients were enrolled and completed a mean follow-up of 18.0 months. Pain relief was observed in 14 of 18 (77.8%) patients on the post-operative day, 14 of 18 (77.8%) at 1-month follow-up, 14 of 17 (82.4%) at 3-months follow-up, 12 of 15 (80%) at 6-months follow-up, 7 of 11 (63.6%) at 1-year follow-up and 2 of 6 (33.3%) 1.5 years of follow-up. Four patients required a repeat cycle of CRT; two at six months of follow-up and two at one year of follow-up. One patient was transferred for surgical intervention at six months of follow-up. Side-effects included facial hypoesthesia (n = 6); nausea/vomiting (n = 2), diminished corneal reflex (n = 13) and difficulty in chewing (n = 11). Severity of adverse effects gradually diminished and none of the patients who are beyond 6 months of follow-up have any functional limitation. Conclusions: CRT is an effective method of pain relief for patients with Trigeminal neuralgia. Successful outcome (excellent or good) can be expected in 66.7% of patients after first cycle of CRF. The incidence and severity of adverse effects is less and the procedure is better tolerated by the patients.

• Journal of International Academy of Physical Therapy Research
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• v.3 no.2
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• pp.475-478
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• 2012

The purpose of this study is to identify the level of masseter muscle tension according to the levels of restricted movement and pain in the temporomandibular joint(TMJ), thereby verifying the fact that excessive masseter muscle tension can be a cause for restricted movement and pain in the TMJ. The subjects of this study were 81 men and women in their 20s and 30s, who feel uncomfortable with their masticatory function on the preferred chewing side. The subjects were measured in terms of the range of motion (ROM) and deviation of the TMJ and the degree of pain in the affected region. The ROM and deviation of the TMJ were measured using the Global Posture System(GPS) after instructing each subject to open his/her mouth to the fullest and taking photos of the subject with a digital camera. The tension of the masseter muscle was measured with a Pressure Threshold Meter(PTM). After the measurements, in order to compare the ROM of the TMJ, the subjects were divided into two groups based on the ROM of above 35mm and below 35mm. For the deviation and pain, based on the average of total subjects, the subjects were divided into two groups of above and below average. Thereafter, the levels of masseter muscle tension were compared between each pair of groups. According to the results, when each variable was compared between the respective two groups, in terms of the deviation, the pressure pain threshold(PPT) of the masseter muscle revealed a statistically significant difference(p<.05). However, the ROM and pain showed no statistically significant difference. Consequently, masseter muscle tension may cause restricted movement in the TMJ. In particular, the deviation and tension in the masseter muscle is considered to be a factor that causes deviation in the TMJ.

• Journal of the Korean Society of Food Culture
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• v.29 no.2
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• pp.163-177
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• 2014

This study aimed to investigate the perception, consumption, and acceptability of convenience mealsin low-income female elderly attending a lunch program at a community well fare center. Using in-depth interviews, qualitative data were collected 11 elderly females ($62.5{\pm}11.2y$) living in Seoul. Participants tried to eat various foods in small-portionsat home, although they ate out what they were offered. Elderly females preferred lunch box-type meals containing a bowl of rice served with toppings, gruel, or Bibimbop due to the growing unavailability of cooking or preparing a meal. Side-dish type convenience mealswere also preferred among elderly females since boiled rice can be easily prepared according to individual preferences. In addition, participants preferred healthy foods. Convenience meal planning and production, appropriate kinds of foods, cooking methods, menus, and packaging should be selected based on the elderly's functional atrophy in chewing, swallowing, digestion, and metabolic diseases. Furthermore, food preferences and comfort foods among the elderlyneed to be identified and characterized. Therefore, more information, including bite size, cutting size, and food texture, should be provided to understand and develop convenience meals for the elderly.

• Restorative Dentistry and Endodontics
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• v.19 no.1
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• pp.231-254
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• 1994

Fracture of cusp, on posterior teeth, especially those carious or restored, is major cause of tooth loss. Inappropriate treatments, such as unnecessarily wide cavity preparations, increase the potential of further trauma and possible fracture of the remaining tooth structures. Fracture potential may be directly related to the stresses exerted upon the tooth during masticatory function. The purpose of this study is to evaluate the fracture resistance of tooth, restored with composite resin inlay. In this study, MOD inlay cavity prepared on maxillary first premolar and restored with composite resin inlay. Three dimensional finite element models with eight nodes isoparametric solid element, developed by serial grinding-photographing technique. These models have various occlusal isthmus and depth of cavity, 1/2, 1/3 and 1/4 of isthmus width and 0.7, 0.85 and 1.0 of depth of cavity. The magnitude of load was 474 N and 172 N as presented to maximal biting force and normal chewing force. These loads applied onto ridges of buccal and lingual cusp. These models analyzed with three dimensional finite element method. The results of this study were as follows : 1. There is no difference of displacement between width of occlusal isthmus and depth of cavity. 2. The stress concentrated at bucco-mesial comer, bucco-disal comer, pulpal line angle and the interface area between internal slopes of cusp and resin inlay. 3. The vector of stress direct to buccal and lingual side from center of cavity, to tooth surface going on to enamel. The magnitude of vector increase from occlusal surface to cervix. 4. The crack of tooth start interface area, between internal slop of buccal cusp and resin inlay. It progresses through buccopulpal line angle to cervix at buccomesial and buccodistal comer. 5. The influence with depth of cavity to fracture of tooth was more than width of isthmus. 6. It would be favorable to make the isthmus width narrower than a third of the intercuspal distance and depth of cavity is below 1 : 0.7.

• Physical Therapy Korea
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• v.26 no.1
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• pp.28-36
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• 2019

Background: Temporomandibular disorder (TMD) is characterized by pain and limited range of motion in the jaw. TMD patients generally prefer to chew on the unaffected or less-affected side, and this tendency often results in asymmetries in masseter muscle thickness and range of mandibular motion. Objects: The purpose of this study was to compare the asymmetries in masseter muscle thickness and range of mandibular motion in subjects with and without temporomandibular disorders. Methods: Thirty-nine subjects were divided into two groups: A TMD group ($n_1=19$) and a control group ($n_2=20$). The jaw opening range and laterotrusion were measured using a digital vernier caliper. The masseter muscle thickness was examined in both the resting state and the maximal clenching state using ultrasonography. The absolute asymmetry indices calculated based on the laterotrusion and masseter muscle thickness of the respective right and left sides. A two-way ANOVA and a Mann-Whitney U test were used for statistical analysis. Results: No significant different was found in the masseter muscle thickness between the TMD and control group. A significant difference was found in the absolute asymmetry indices of mandibular laterotrusion between the TMD and control groups (p<.05). Furthermore, the ranges of jaw opening were significantly different between males and females (p<.05). The absolute asymmetry index values of masseter muscle thickness at rest and during maximal clenching were also significantly different between males and females (p<.05). Conclusion: These results demonstrated that the subjects with TMD had a larger degree of asymmetry in laterotrusion than those without TMD. Therefore, a physiotherapy program needs to be designed to restore normal laterotrusion capacities for TMD subjects. These results also showed that female subjects had greater absolute asymmetry indices in masseter muscle thickness than male subjects. Therefore, more training is needed to promote bilaterally balanced chewing among women.

• Journal of Dental Rehabilitation and Applied Science
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• v.35 no.1
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• pp.37-45
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• 2019

In the case of edentulous patients, the total amount of occlusal force is dispersed by the keratinized gingiva during mastication, in result, causing lower masticatory and chewing efficiency. In particular, the mandibular area has more side effects such as pain than the maxilla has. It gets worse when the patient has more absorption of alveolar bone, but the implant treatment is often interrupted due to the existence of the inferior alveolar nerve. In this case, a patient treated with the all-on-4 method by placing the implant in the anterior part of mandible and with the conventional complete denture for the maxilla has maintained without complications and was satisfied with the restoration both functionally and esthetically.

• The korean journal of orthodontics
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• v.53 no.5
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• pp.298-306
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• 2023

Objective: Pain following the insertion of separators and archwires varies with age, sex, race, ethnicity, threshold, and health status. This study aimed to evaluate the characteristics of pain in orthodontic patients after the insertion of elastomeric separators, its effects on daily life, and its association with age and sex in a population not previously studied in this regard. Methods: A cross-sectional study of 130 patients undergoing orthodontic treatment included collecting data on demographics, pain experienced following the placement of separators, time of onset, duration, characteristics, change in dietary pattern or chewing side, intake of analgesics, and severity of pain on the Wong Baker's scale. The results are reported as counts and percentages. Associations between sex and age were evaluated using Pearson's chi-square test. Results: Among the 130 patients, 56.2% were 9-20 years old, 63.8% experienced pain following the insertion of separators, 22.9% had their first episode of pain at 4 hours, 56.6% experienced intermittent pain, and 37.3% experienced discomfort; 18.1% males and 81.9% females experienced pain following the insertion of separators. Pearson's chi-square test showed a significant association between pain and sex (P = 0.04). Most patients (37.3%) reported "hurts little more" for pain intensity on Wong Baker's scale and 21.7% reported all four quadrants as sites of pain. Conclusions: The pain experienced after separator insertion was associated with sex and age. Females experienced more pain than males and patients between the age range of 21 and 36 years suffered more pain during mastication than between 9 and 20 years old.