• Journal of Periodontal and Implant Science
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• 제45권6호
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• pp.205-209
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• 2015

Purpose: Dental implants present several advantages over other tooth replacement options. However, there has been little research on masticatory function in relation to implant treatment. Therefore, the aim of the present study was to evaluate the improvement of masticatory function two weeks after implant restoration. Methods: Masticatory ability was evaluated with the subjective food intake ability (FIA) and objective mixing ability index (MAI) methods. Fifty-four subjects with first and second missing molars completed the study. The subjects were asked to complete a self-reported questionnaire about 30 different food items, and to chew wax samples 10 times both before and two weeks after implant restoration. A total of 108 waxes were analyzed with an image analysis program. Results: Dental implant restoration for lost molar teeth on one side increased the FIA score by 9.0% (P<0.0001). The MAI score also increased, by 14.3% after implant restoration (P<0.0001). Comparison between the good and poor mastication groups, which were subdivided based on the median MAI score before implant restoration, showed that the FIA score of the poor group was enhanced 1.1-fold while its MAI score was enhanced 2.0-fold two weeks after an implant surgery. Conclusions: Using the FIA and MAI assessment methods, this study showed that masticatory function was improved two weeks after implant restoration. In particular, the enhancement of masticatory function by implant restoration was greater in patients with relatively poor initial mastication than in those with good initial mastication.

• Imaging Science in Dentistry
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• 제34권1호
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• pp.31-34
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• 2004

Purpose: To compare the size of the masseter and lateral pterygoid muscle between the affected and the unaffected side of the patients who have the chief complaints of the mandibular asymmetry. Materials and Methods: Twenty two patients (male: 4, female: 18, average age: 21.3 year-old) were radiographed using posterior-anterior (P-A) cephalography and computed tomography (CT). On P-A cephalography, the degree of deviation was determined by the distance from the mentum to the vertical reference line through the crista galli and the anterior nasal spine. On the scanned tracing papers of the maximum cross-sectional area of the masseter and lateral pterygoid muscle using axial CT images, the pixel number was measured. The ratio of the affected : unaffected sides were obtained. For the masseter and lateral pterygoid muscle, the relationship between the muscular volume and degree of skeletal hypoplasia was studied. Results : The half cases showed no skeletal asymmetry. The lateral pterygoid muscle of the affected side was larger significantly than unaffected side (p<0.05). However, there was no significant difference between two sides in the cases of skeletal asymmetry. There was only significant difference in the cases without skeletal asymmetry (p<0.05). Conclusions : To some extent, the slight mandibular hypoplasia could affect the growth of some masticatory muscles.

• Journal of Oral Medicine and Pain
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• 제21권2호
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• pp.265-277
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• 1996

The aim of this study was to investigate the electromyographic(EMG) activity of masticatory and cervical muscles according to chewing pattern in coronal plane during gum chewing. 70 patients with temporomandibular disorders and 30 dental students without any signs and symptoms of the disorders participated in this study. We measured the activity of masseter (MM), anterior temporalis(TA), sternocleidomastoideus(SCM) and trapezius muscle and recorded the chewing patterns using Biopak system synchronously. Chewing pattern was classified into S- or L-pattern by the midline opening path and short or long type by the lateral distance from midline. Obtained data were analyzed with SAS/STAT Program. The obtained results were as follows : 1. Generally, there was tended to be higher activity in the control group than in the patients group. 2. When comparing EMG activity according to preferred side, the muscle activity was tended to higher on the preferred chewing side than on the contralateral side. However, this difference is insignificant statistically 3. In unilateral affected patients, there was no difference in muscle activity between affected chewing side and unaffected chewing side except for the EMG of the temporalis anterior muscle. 4. Despite the varietal in each of the following variables, there mere no differences in EMG activity during gum chewing: chewing pattern in coronal plane and lateral distance of chewing. 5. The activity of SCM in chewing side was higher than that in contralateral side (p<0.001), but there was no difference in trapezius muscle. 6. In all of the control group, there was appeared L-chewing pattern than not involved the midline during preferred side chewing.

• 대한치과보철학회지
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• 제36권4호
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• pp.598-614
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• 1998

This study was performed to investigate the influence of lateral guidance pattern and chewing pattern on masticatory muscle activity and occlusal contact pattern. Twenty-five patients with temporomandibular disorders and thirty students without temporomandibular disorders were selected for this study. Electromyographic examination and occlusal contact examination were performed simultaneously with Bio-Pak System (Bioresearch Inc.,U.S.A.) and T-Scan System(Tekscan Co., USA). The obtained results were as follows : 1. The EMG activity of masseter and anterior temporal muscle in patient group with canine guidance was higher than with non-canine guidance. but there was no significant difference (p>0.05). 2. The EMG activity of anterior temporal muscle in normal group with non-canine guidance was higher at preferred chewing side than at opposite side (p<0.05). 3. The EMG activity of masseter muscle was higher in normal group than in patient group (p<0.05). 4. The number of occlusal contact in patient group with canine guidance was higher than with non-canine guidance, but there was no significant difference (p>0.05). 5. The occlusal contact force at preferred chewing side was higher in patient group than in normal group(p<0.05).

• Journal of Oral Medicine and Pain
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• 제12권1호
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• pp.53-61
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• 1987

In order to evaluate the effect of unilateral tooth clenching, the author observed a feature of producing the symptom complex related to pain and discomfort by the isometric unilateral canine biting under force of 5kg(FS) in Korean 31 adult females within normal masticatory function who were divided into the bilateral, the right and the left group according to their habitual sides of mastication, and analyzed the observed data statistically. The obtained results were as follows: 1. The duration of the isometric unilateral canine biting maintained before the occurrence of symptom complex related to pain and discomfort 66.72 seconds at right side and 39.50 seconds at left side in a group of subjects with bilateral habitual mastication. And the difference of the duration between of unilateral biting side was almost significant (P<0.05). 2. The most frequent region of occurrence of symptom complex related to pain and discomfort by the isometric unilateral canine biting was the contralateral superficial masseter muscle in a group of subjects with bilateral habitual mastication.

• 대한치과보철학회지
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• 제28권2호
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• pp.175-182
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• 1990

This study was performed to investigate the influence of occlusal change on the masticatory muscle activity. 8 students without any symptom of T.M.J. dysfunction, any history of prosthodontic or orthodontic treatment on dental college of WonKwang Univ. were participated in this study. The activity of masseter and anterior temporal muscles were measured by bioelectric processor(EM2, Myotronics, Inc., U.S.A.) during voluntary maximal clenching on natural teeth, by splint with bilateral posterior surface contact, by splint with unilateral posterior surface contact, and by splint without unilateral posterior teeth contact. The obtained results were as follows ; 1. The loss of posterior contact on noe side resulted in change of the activity of anterior temporal and masseter muscle during clenching on ipsilateral side, but there was no change of muscle activity on contralateral side. 2. The activity of anterior temporal and masseter muscle during clenching were not affected by the pattern of occlusal contact. 3. There were no difference between the activity of anterior temporal and masseter miuscle during clenching by natural teeth and by occlusal splint.

• Journal of Oral Medicine and Pain
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• 제21권2호
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• pp.293-304
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• 1996

The purpose of this study was to investigate the peak electromyographic activity(EMG) and time intervals in firing sequence of Anterior temporalis(TA) and Masseter(MM) on clenching, the number of tender points in the head and neck muscles, the occlusal contact state on clenching, and their relationship. 78 patients with Temporomandibular Disorders(TMDs) participated and were classified into articular or muscular group by clinical signs and symptoms. BioEMG$\textregistered$ of integrated masticatory function analyzer, Biopak$\textregistered$ system(Bioresearch Inc., USA), was used to measure EMG and related items, and T- Scan$\textregistered$(Tekscan, USA), computerized occlusal analyser, was used to record occlusal contact state on maximum voluntary clenching. EMG and occlusal contact were synchronously recorded and analysed with SAS Statistical program. The results of this study were as follows : 1. In total subjects, EMG of TA was lower than that of MM in articular group but in muscular group, vice versa, As a result, the ratio TA to MM was significantly different between the two groups. no significant differece. 3. The number and force of occlusal contact were more in articular group, but there was no significant difference in Total Left-Right statistics(TLR) between the two groups. 4. In unilaterally affected subjects for muscle function, no significant difference was observed between the affected side and the contralateral side in articular group, but in muscular group, the item of the number of tender points showed significant difference. However, for occlusal contact items, contact force in articular group shows significant difference between the two sides. 5. Rate of coincidence of the first firing side of TA with affected side or preferred chewing side was higher and not different between the two groups, but no significant correlation was showed between the first firing side and the first occlusal contact side.

• 대한치과교정학회지
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• 제22권2호
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• pp.389-412
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• 1992

Along with form and function relationship of craniofacial growth comes a concern for the masticatory muscles with postnormal occlusion. It is the aim of this study to grope the certain differences upon the electromyographic activities of the masticatory muscles between normal occlusion and class II malocclusion during the varieties of oral functions. 26 persons of normal occlusion whose mean age were 18.9-25.6 years and another 26 persons of class II malocclusion whose mean age were 19.0-28.9 years served for this study. The electromyographic recordings processed by $Medelec^{\circledR}$ MS 25 EMG apparatus were taken from the anterior and posterior temporal, and anterior and posterior masseter muscles of both sides, and suprahyoid muscles as well. Analyses of the data toward such specific activities as mandibular rest, maximal biting, chewing gums and swallowing peanuts turned out the following summary and conclusions. 1. The maximal mean amplitude of the posterior temporalis showed significant augmentation in class II malocclusion, however the anterior temporalis, posterior masseter, and suprahyoid muscles manifested meaningful diminutions. 2. Stronger posterior temporalis and weaker anterior masseter and suprahyoid muscles were arranged in maximal biting with parameters of maximal mean amplitude. 3. The anterior temporalis of working side expressed smaller maximal mean amplitude in class II malocclusion. Significant swelling in duration were shown at anterior and posterior temporalis of working side, and posterior temporalis of balancing side in class II malocclusion, and marked reduction at anterior masseter of balancing side and posterior masseter of working side as well. The lessened latency were expressed at anterior masseter of working side, and anterior and posterior masseter of balancing side. Class II malocclusion group had significant prolongation of silent period duration. Mean silent period duration of 10.75 msec in normal occlusion and 24.37 msec in class II malocclusion were calculated. 4. Significant augmentations of maximal mean amplitude while swallowing peanuts were yielded at right anterior temporalis and posterior temporalis of both sides, however left anterior masseter and right posterior masseter showed diminution. No significant differences in duration showed at every muscle examined in class II malocclusion group.5. Weaker masseter and stronger temporalis were suggested as characteristics of class II malocclusion.

• Journal of Oral Medicine and Pain
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• 제15권1호
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• pp.27-35
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• 1991

In order to evaluate muscular activity patterns of masticatory muscles and asymmetry patterns of muscular activity according to the levels of occlusal force, twenty-one individuals of age ranged from 23 to 27 years were examined. They were selected according to the following criteria : 1) no symptoms of temporomandibular disorder, 2) complete dentition except third molars, 3) normal or Angle's class I molar relationship and 4) no experience of dental treatment. The electromyographic amplitudes was measured for evaluation of muscular activity and asymmetric patterns of masseter and anterior temporal muscle during unilateral clenching at the levels of 10%, 20%, 40% and 50% of the maximum occlusal force by use of electromyogram and bite force meter. The obtained results were as follows : 1. The muscle activity indices of masticatory muscles of clenching side at the clenching levels of 10%, 20% and 30% of the maximum occlusal force were -19.12, -9.87, -0.49%, so that activity of anterior temporal muscle was dominant than that of masseter muscle. At the levels of 40%, 50% of the maximum occlusal force, muscle activity indices were 4.68%, 6.70%, so that activity of masseter was dominant at all level and as the levels of occlusal force was increased, muscular activity index was tend to decrease. 2. In masseter, asymmetry indices of muscular activity at the levels of 10%, 20% of maximum occlusal force were -10.34 and -1.24%, so that muscular activity of non-clenching side were dominant and at the levels of 30%, 40% and 50% each of maximum occlusal force, muscular activity was dominant on clenching side as 4.68, 7.18 and 10.9%. In anterior temporal muscle, asymmetry indices were 33.38%, 25.46, 2095, 10.23 and 15.45% at the levels of 10%, 20%, 30%, 40% and 50% each of maximum occlusal force, so that activity of clenching 15.45% at the levels of 10%, 20%, 30%, 40% and 50% each of maximum occlusal force, so that activity of clenching side was dominant than that of non-clenching side at all levels, but as the levels of occlusal force was increased, asymmetry indices of muscular activity was tend to decrease. 3. Between both sides, average electromyographic amplitudes of masseter and anterior temporal muscle were correlated, so that as the levels of occlusal force was increased, average electromyographic amplitudes of both side in same muscle were increased proportionally. But asymmetry indices between muscular activities of masseter and anterior temporal muscle were not correlated.

• Journal of Oral Medicine and Pain
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• 제31권2호
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• pp.167-176
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• 2006

최근에 안모에 관심이 증가하면서 안모비대칭에의 불편을 호소하는 환자가 증가하고 있으며 안모 비대칭 평가에는 고가의 3차원적인 영상이 많이 이용되었다. 본 연구에서는 치과영역에서 쉽게 접할 수 있으며 비교적 저렴한 파노라마방사선 사진과 정모방사선 사진을 이용하였다. 안모 비대칭에 대한 골격적인 평가를 하고자 본 연구에 지원한 대상자 중에 특이할만한 전신 질환자나 특이한 교합을 지닌 대상을 제외한 35명을 택하여 파노라마 방사선 사진과 정모 방사선 사진을 촬영하였으며, 저작 형태와 안모 비대칭을 인지하는 정도를 설문지 형식으로 조사하여 다음과 같은 결과를 얻었다. 1. 파노라마 방사선 사진상의 좌우측 비교에서 하악의 수직적 측정 항목인 Co-Go(p<0.05), Co-Ag(p<0.05)에서 하악각 측정 항목에서는 Co-Go-Ag(p<0.05), Go-Me-Ag(p<0.01) 유의한 차이를 보였다. 2. 파노라마방사선 사진에서 저작측에 따른 평가에서는 하악의 수직적 길이측정치에서 우측 저작자는 Co-Ag(p<0.01) 좌측 저작측에서는 Co-Go(p<0.05)에서 유의성을 보였다. 3. 정모 방사선사진 상의 좌우측 안모비대칭 비교에서는 Cg-Go(p<0.01), 우측 저작자에서는 Co-Ag(p<0.01) 좌측 저작자에서는 Cg-Go(p<0.05)에서 유의한 차이를 보였다. 4. 안모비대칭이 있다고 인지하는 군에서 하악의 수직적 측정 항목인 Co-Go(p<0.05)에서 유의성을, 하악각의 측정항목인 Co-Si-Cr(p<0.05), Go-Me-Ag(p<0.05)에서 유의성을 보였다. 안모가 좌측이 더 길다고 인지하는 군에서는 Go-Ag(p<0.05)의 수평적 계측 항목이 우측이 더 길었으며, 우측안모가 길다고 인지하는 군에서는 Co-Go(p<0.05)와 Co-Ag(p<0.01)의 하악의 수직적 측정치에서 유의성을 보였다.