• Journal of International Academy of Physical Therapy Research
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• v.11 no.1
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• pp.1954-1959
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• 2020

Background: Due to aging, blood flow rate decreases, also posture and chewing habit may be changed. Objective: To identify that changes in blood velocity in the common carotid arteries (CCAs) in old persons with unilateral chewing habit (UCH) and forward head posture (FHP) in the elderly. Design: An observational cross-sectional study. Methods: Chewing habits, FHP, and CCAs velocities were assessed in 85 elderly subjects. Chewing habits were measured by visual observation. CCAs measured the peak systolic velocity (PSV), end-diastolic velocity (EDV), minimum diastolic velocity, and resistivity index. The subjects were divided into UCH and bilateral chewing habit groups depending on chewing habit. The subjects were also divided into >49 degrees and <49 degrees for comparison of blood flow between the left and right CCAs. Results: In the UCH, the chewing side had significantly higher EDV (P=.003), PSV (P=.023) than the non-chewing side. There was no significant difference in velocity between the CCAs in the FHP. Conclusion: This study shows that the blood flow velocity of the chewing side of UCH was higher, and unilateral chewing affects the CCAs velocity and thus highlight the importance of chewing habit in the elderly than head posture.

• The Journal of Korean Academy of Prosthodontics
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• v.40 no.6
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• pp.577-589
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• 2002

There are several variations in normal mastication. In them, unilateral mastication is chewing, predominantly on a preferred side of the dentition and hardly on e non-preferred side. Continual unilateral mastication may alter the coordination of masticatory muscles. Although they studied about these EMG of masticatory muscles, there were no information about characteristics of masticatory muscle activity in unilateral mastication. Therefore, In this study, we investigated the activity of the masseter and anterior temporal muscles during rest, clenching in maximum intercuspation and gum chewing in habitually unilateral mastication group compared with normal group and tried to know effects of continual unilateral mastication on activity of masticatory muscles. The results of this study were as follows 1. In electromyographic activity during rest, in bilateral mastication group pattern of muscle activity of right and left side was symmetrical. But, in unilateral mastication group, records of anterior part of temporal muscle was higher than that of bilateral mastication group (p<.01) and patterns of muscle activity of right and left side in both muscle were asymmetrical.(p<.05) 2. In electromyographic activity during clenching in maximum intercuspation, records of superficial part of masseter muscle were higher than anterior part of temporal muscle in both group. Muscle activity of temporal muscle in unilateral mastication group was a little higher han bilateral mastication group and asymmetry of activity pattern in temporal and masseter muscle was shown but these differences were not statistically significant. (p<.05) 3. In electromyographic activity during gum chewing, temporal muscle was activated earlier than masseter muscle and maximum bite force is derived from masseter muscle in both group. In unilateral mastication group, electromyographic activity of masseter and temporal muscle of preferred chewing side, regardless of right or left side chewing, was higher than that of bilateral mastication group and especially, difference in masseter muscle was statistically significant. (p<.01) Based on the above results, our study suggested that recording of masticatory muscle activity will be helpful in the effective diagnosis and treatment of some types of the parafunctional habits.

• Journal of Yeungnam Medical Science
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• v.13 no.2
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• pp.308-323
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• 1996

This study tried to find the prevalence and distribution of temporo-mandibulr disorders(TMD) for workers (employee) in Seoul area to investigate the correlation between TMD and possible etiological factors such as general muscle and joint symptoms, headache, unilateral chewing and parafunction. This study was an epidemiological investigation of answers obtained from 282 persons by questionaire from Aug. 1995 to Nov. 1995. The major findings from the questionaire were as follows. (1) 43.26% of the subjects(282 persons) has TMD. (41.88% of man and 43.26% of women) (2) The more often people have general muscle and joint symptoms and headache, the more susceptible they are to TMD. Their correlation was very significant(p<0.001). (3) The more people have bad oral habits such as bruxism, clenching and biting habit, the more likely they have TMD. The more sensitive people are to stress, the more frequently they have bad oral habits such as bruxism, clenching and biting habit. (4) Unilateral chewing has higher TMD index than bilateral chewing. There is no relationship between ache areas and TMD index.

• Journal of Oral Medicine and Pain
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• v.38 no.2
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• pp.175-185
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• 2013

Objective : Condyle hypoplasia in temporomandibular joint(TMJ) is often observed in several radiographic views. Mandibular Condyle hypoplasia is frequently confused with osteoarthritis with bony changes in TMJ. This paper investigated clinical characteristics of mandibular condyle hypoplasia as compared with TMJ osteoarthritis. Material and method : 276 patients with TMD were taken clinical and radiological examination and were divided into study group, 189 patients diagnosed with mandibular condyle hypoplasia, and control group, 87 patients diagnosed with TMJ osteoarthritis. And clinical features(Onset, Overjet, Overbite, Noise, Locking, NAS of noise, LOM, pain, MCO, and site of diagnosis and pain)of the two groups were compared. Results : 1. Mandibular condyle hypoplasia and TMJ osteoarthritis were similar in many of the clinical features. 2. Mandibular condyle hypoplasia concordance rates of the radiographic diagnosis site and the pain site was significantly lower than TMJ osteoarthritis. 3. Bilateral mandibular condyle hypoplasia group had more occlusal discomfort, and clenching habits than unilateral mandibular condyle hypoplasia group. 4. Unilateral mandibular condyle hypoplasia group had more unilateral chewing habits and LOM than unilateral TMJ osteoarthritis group. Unilateral TMJ osteoarthritis group had more morning stiffness and higher concordance rates of the radiographic diagnosis site and the click sound site than unilateral mandibular condyle hypoplasia group. 5. Bilateral mandibular condyle hypoplasia group had more usual headaches and overjet than bilateral TMJ osteoarthritis group. Conclusion : Mandibular condyle hypoplasia has somewhat distinguishing clinical characteristics as compared with TMJ osteoarthritis.

• Journal of Korean society of Dental Hygiene
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• v.11 no.6
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• pp.853-862
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• 2011

Objectives : The aim of this study was to investigate the number of self-report symptoms for temporomandibular disorders(TMD) and related factors in the third grade students of high school. Methods : A total of 1,043 high school the 3rd students age 16 20 completed a questionnaire from 11 high schools in Andong city from April to June 2010. Student's t-test was used to analyze the difference of TMD number. Multiple regression analysis was performed to determine the effects of independent variables on TMD number. Results : 1. Students who have one TMD were 71.3%, two 41.7% and over three 25.7%, respectively. 2. The number of TMD symptom of students who have no good habits such as clenching, bite lip and cheeks, resting on hand, chewing gum, hard foods, and unilateral chewing was a statistically significant higher than those who doesn't have ones(p=0.00). 3. TMD number of students who have been under more stress was a significantly higher than those who didn't have been(p=0.00). 4. Bite lip and cheek(${\beta}$=0.03, p=0.037), chewing gum(${\beta}$=0.03, p=0.029), resting on hand(${\beta}$=0.04, p=0.006), hard foods(${\beta}$=0.07, p=0.000), and stress out(${\beta}$=-0.03, p=0.018) were significantly associated with TMD number by multiple regression analysis. Conclusions : Variables associated with TMD were bite lip and cheek, chewing gum, resting on hand, hard foods, and stress out factor. According to our findings, it is so important to teach good habits on oral health to the 3rd grade students in high school. Further prospective study should explore cause of TDM from those variables.

• Journal of Oral Medicine and Pain
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• v.41 no.3
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• pp.110-117
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• 2016

Purpose: The purpose of this study is to determine factors influencing the duration of occlusal appliance (OA) treatment for patients with temporomandibular joint (TMJ) internal derangement. Methods: Ninety patients were included for this study, who satisfied the following including criteria: (i) those who were diagnosed as disc displacement of TMJ by taking magnetic resonance imaging (MRI) and (ii) those who were finished OA treatment. The subjects were classified into three groups according to the period of OA treatment: (i) early response group (<6 months), (ii) moderate response group (6 months-1 year), and (iii) delayed response group (>1 year). Demographic data, data from chief complaints and past history of temporomandibular disorder, data from clinical examination and diagnostic imaging including panoramic view and TMJ MRI were compared among groups. One-way ANOVA and chi-square analysis were used to test statistical significance. Results: There were no significant differences in demographic data, data from chief complaints and TMJ imaging. However, only the prevalence of oral parafunctional habits including bruxism, clenching, and unilateral chewing showed significant differences among groups. Conclusions: Oral parafunctional habits could be factors to influence the duration of OA treatment in the patients with TMJ internal derangement.

• Journal of Oral Medicine and Pain
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• v.20 no.2
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• pp.407-420
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• 1995

This study was performed to evaluate and compare conservative treatment results by several parameters such as age, sex, symptom duration, type and timing of joint sound, parafunctional habits, splint type, and diagnostic classification. There have been too many articles reporting long term results of conservative treatment but articles related to comparison of treatment results by patients' self-evaluation have been rarely reported. For this study 258 patients with temporomandibular disorders(TMDs) were selected and examined by routine diagnostic procedure for TMDs. The subjects were classified into 5 TMDs subgroups ad treated with conservative treatments involving splints, physical modalities, jaw exercises, and counseling. Visual analogue scale(VAS) about pain, joint sound, and mouth opening limitation was recorded respectively during treatment period. From the VAS data and treatment duration, VAS treatment index(VAS Ti) was calculated. The obtained results were as follows : 1. Pain was the most frequent main symptom in subjects with temporomandibular disorders, and main symptom for mouth opening limitation was comparatively less than for pain or sound in disk displacement with reduction group or in degenerative joint disease group. 2. Degenerative joint disease group had the most poor treatment results and highest occlusal index of Helkim's index. 3. Good prognosis for conservative treatment was observed in acute group, under 6 months than chronic group, 6months over in symptom duration, and subjects with 40 years over in age showed the most poor prognosis. 4. Subjects treated with anterior repositioning splint had better treatment results than subjects treated with centric relation splint, but statistical significance in VAS Ti and treatment duration was not observed. 5. Treatment results according to affected side, types and point of joint sound did not show consistent statistical results. 6. The result for conservative treatment was observed poor in subjects with bruxism and clenching. 7. In studying coincidence between preferred chewing and affected side, frequency of preferred chewing side, in unilateral affection, was higher in ipsilateral than in contralateral side.

• Journal of Oral Medicine and Pain
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• v.20 no.2
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• pp.257-267
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• 1995

An Epidemiologic study was carried out on 77 TMD patients with degenerative joint disease who had visited the Orofacial Pain Clinic in Pusan National University Hospital. Al subjects were interviewed and examined clinically and radiologically using a standardized examination form. As related to gender and duration, subjective and objective sysmptoms in DJD patients were studied. The obtained results were as follows : 1. There were much more patients in the twenties or thirties, women and histories such as chronic duration and microtrauma. 2. Most patients responded positively more often to the questions of jaw function, unilateral chewing in habits, poot appetite and depression in behavioral response and shoulder pain in worsening prognosis 3. While the most common reasons for treatment were pain, noise, and limitation of opening, the associated symptoms such as headache, neckache, earache, jaw dysfunction, neck dysfunction, acute bite change and dizziness, ringing or fullness in the ears as secondary CNS excitatory effects were complained. 4. Opening the mouth in 25 to 40mm, soft end feel and deflective incisal pathway were seen and more tenderness to lateral or dorsal capsule of joint than intra or extra oral muscles were complained. 5. While there appeared no click, crepitus and single click in acute group, in chronic group, crepitus, single click and no click appeared in order of sequence. 6. Tomogram or bone scan revealed more bony changes than panorama and transcranial view.

• Journal of Oral Medicine and Pain
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• v.21 no.1
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• pp.67-78
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• 1996

This study was performed to compare the TMJ sounds by means of vibration-related items by Sonopak such as integral, high integral, above 300/(0-300) ratio, peak amplitude, peak frequency and median frequency before and after occlusa1 splint therapy as well as counselling, physical modalities. For this study 22 patients with craniomandibular disorders (CMDs) were selected and examined by routine diagnostic procedure for CMDs including Transcranial and Panoramic radiographs and were classified into 3 CMDs subgroups : disc displacement with reduction, disc displacement without reduction, and degenerative joint disease. Visual analogue scale (VAS) about joint sound was recorded during treatment period and VAS treatment index (VAS Ti) was calculated from the VAS data and treatment duration. The author evaluated and compared treatment results by several parmeters such as symptom duration, timing of joint sound, parafunctional habits, trauma, and diagnostic classification. The obtained results were as follows : 1. Before the treatment, the highest value of peak amplitude was observed in disc displacement with reduction group and value of median frequency was highest in degenerative joint disease group. In addition the highest values of peak frequency and ratio ware observed in degenerative joint disease group, though they were not significant. Furthermore the lowest value of high integral was observed in disc displacement without reduction group and though it was not significant, value of integral was lowest in that group. 2. Among 3CMDs subgroups disc displacement with reduction group showed the significantly decreased value of high integral and degenerative joint disease group had the significantly decreased value of integral after conservative treatment including occlusal splint therapy. Conclusively conservative treatment including occlusal splint therapy vay be effective in the treatment of CMDs including TMJ sound. 3. Fair prognosis for conservative treatment was observed in acute group under 6 months than chronic group, 6 months over in symptom duration but there was no statistical difference. The result for conservative treatment was observed slightly poor in subjects with bruxism, clenching, unilateral chewing habit and trauma history but there were no statistical differences.