• Physical Therapy Korea
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• v.13 no.4
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• pp.39-46
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• 2006

The purpose of this study was to determine the effects of slump sitting postures on the masticatory, neck, shoulder, and trunk muscles associated with work-related musculoskeletal disorders (WRMD). Eleven healthy adults (age, $23.3{\pm}2.7$ yrs; height, $174.0{\pm}4.1$ cm; weight, $61.4{\pm}6.6$ kg) participated in this study. The participants were free of injury history and neurologic deficits in the masticatory, neck muscles and upper extremities at the time of participation. The subjects were asked to perform erect and slump sitting postures under the guidance of physical therapists. The surface electromyography (EMG) was recorded from the anterior temporalis, masseter, upper trapezius, serratus anterior, middle trapezius, L3 paraspinal, external abdominal oblique, gluteus maximus muscles of 11 adults as they performed visual terminal display work, which are known as the weakened and tightened muscles owing to WRMD. The recorded signals were averaged and normalized to the mean amplitude of the EMG signal obtained during submaximal reference voluntary contractions. The results of study were as follows: The masseter, upper trapezius, serratus anterior, middle trapezius, L3 paraspinal, external abdominal oblique muscles significantly differed in the slump sitting posture (p<.05). The muscle activities of the serratus anterior, middle trapezius muscle, and external abdominal oblique were significantly lower and that of the masseter, upper trapezius, L3 paraspinal muscles were significantly higher. Further research is needed to assess the motor control problems and the function of the deep muscles in posture stability of patients with WRMD.

• Journal of Oral Medicine and Pain
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• v.30 no.3
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• pp.337-344
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• 2005

A tactile sensor employs a piezoelectric element to detect contact frequency shifts and thereby measure the stiffness or softness of material such as tissue, which allows the sensor to be used in many fields of research for urology, cardiology, gynecology, sports medicine and caner detection and especially for cosmetics and skin care. In this study, reliability of the tactile sensor system was investigated with its manual application to the muscles susceptible to temporomandibular disorders. Stiffness and elasticity of anterior temporalis, masseter and trapezius muscles were calibrated bilaterally from 5 healthy men with an average of 24.5$\pm$0.94 years. The tactile sensor used in this study had a computer-controlled and motor-driven sensor unit which automatically pressed down on the skin surface over the muscles being measured and retracted, thereby providing the hysteresis curve. The slope of the tangent of the hysteresis curve (${\Delta}f/{\Delta}x$) is defined as stiffness of the muscle being measured and the distance between the two parts of the curve as its elasticity. To determine inter-examiner reliability, all the measurements were performed by the two examiners A and B, respectively and the same examination were repeated with an interval of 2 days for intra-examiner reliability. The results from this study demonstrated high reliability in measuring stiffness and elasticity of anterior temporalis, masseter and upper trapezius muscles using a tactile sensor system. It is suggested that the tactile sensor system can be a highly reproducible and effective instrument for quantitative evaluation of the muscle in head and neck region.

• Journal of Oral Medicine and Pain
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• v.35 no.1
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• pp.49-59
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• 2010

The purpose of this study was to investigate short-term masticatory muscle reactions in response to simulated noise and music sound. Hypothesis of this study was that loud noise would cause increased stiffness and decreased elasticity of the masticatory muscles compared to low level of noise or identical sound level of music. Fifteen male volunteers were recruited for the study. The sound levels of noise and music used here were 60 dB and 100 dB. The experiment comprised 4 sessions, Session 1 with 100 dB of noise for the 1st day of experiment: Session 2 with 100 dB of music for the $2^{nd}$ day: Session 3 with 60 dB of noise for the $3^{rd}$ day: Session 4 with 60 dB of music for the $4^{th}$ day. Stiffness and elasticity on the anterior temporalis and superficial masseter muscles were measured with tactile sensor before and 2, 4 and 6 minutes after exposure of sound. The study indicated that, in short-term exposure of sound, there was no significant difference between noise and music at both 60 and 100 dB of sound level, but that there were partially significant differences between 60 and 100 dB of sound level regardless of sound type. This suggest that high level of sounds like 100 dB used in this study, in spite of short term exposure of several minutes, would lead to masticatory muscle contraction, especially in the masseter muscles.

• Journal of Oral Medicine and Pain
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• v.33 no.4
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• pp.339-352
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• 2008

Aims: The aims of this study were to identify the association between cervical muscle pain and TMD by pressure pain response, and to find cervical muscles showing moderate to severe pressure pain that are correlated with masticatory muscle pain. Methods: Patients(n=129, female 65.9%, mean age 28.8 years) answered a TMD questionnaire asking about headache, neck pain, emotional stress, sleep disturbance, parafunction habits, and pain intensity. A clinical examination of the masticatory system was performed. Of the neck muscles, (1) the upper sternocleidomastoid, (2) the middle sternocleidomastoid, (3) the upper trapezius, (4) the splenius capitis, (5) the semispinalis capitis, (6) the scalene medius, and (7) the levator scapulae muscles were examined by palpation. Pressure pain or tenderness of all palpation sites was scored from 0 to 3 according to the pain response. The variables of sum of pressure pain scores were calculated from pressure pain scores and were used for statistical analyses. Results: Eighty patients(62.0%) answered that they suffer from neck pain in the TMD questionnaire. More than 40% of sternocleidomastoid and upper trapezius examination sites showed moderate to severe tenderness in the cervical muscles, and 36% of middle masseter in the masticatory muscles. For the 129 patients, the sum of cervical muscle pain scores(mean=12.88, SD=8.06) and the sum of TMD pain scores(mean=5.36, SD=5.10) were moderately correlated($\rho$ = 0.502, P < 0.001). The sum of TMD pain scores tends to increase as the sum of cervical muscle pain scores increases(Y = 0.395${\cdot}$X, $R^2$ = 0.659, P < 0.001). In the patients with masticatory muscle disorders, the sum of sternocleidomastoid and upper trapezius pain scores(mean = 8.67, SD = 4.95) and the sum of temporalis and masseter pain scores(mean = 3.37, SD = 3.56) showed moderate correlation($\rho$ = 0.375, P < 0.001). Those two variables were in a proportionate relationship(Y = 0.359${\cdot}$X, $R^2$ = 0.538, P < 0.001). In a partial correlation analysis of the sum of unilateral pain scores, the sum of right cervical muscle pain scores and the sum of left cervical muscle pain scores showed the highest correlation(r = 0.802, P < 0.001). The sum of right TMD pain scores and the sum of left TMD pain scores were moderately correlated(r = 0.481, P < 0.001). For the twenty patients with unilateral TMD pain, the partial correlation coefficient between the sum of ipsilateral cervical muscle pain scores and the sum of contralateral cervical muscle pain scores was the largest(r = 0.597, P = 0.009). A partial correlation between the sum of primary TMD side pain scores and the sum of ipsilateral cervical muscle pain scores was 0.564(P = 0.015). Conclusions: TMD is associated with cervical muscle pain on condition of pressure pain response to palpation. Of the cervical muscles, sternocleidomastoid and upper trapezius frequently exhibit moderate to severe pressure pain, and they are closely related to the masticatory muscle pain. The characteristic of symmetric involvement of pain is prominent in cervical muscles; however, TMD can affect the level of cervical muscle pain to modify its symmetric nature.

• Korean Journal of Head & Neck Oncology
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• v.1 no.1
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• pp.35-61
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• 1985

The surgical treatment of advanced carcinomas and some benign tumors having clinically malignant behaviors of the head and neck region often require extensive resection, necessitating large flaps for reconstruction. Since the original upper arm flap was described by Tagliacozzi in 1597, a variety of technique such as random pattern local flap, axial flap, distant flap, scalping flap, myocutaneous flap, free flap etc. have been proposed for reconstruction of head, face and neck defects. Reconstruction of the facial defects usually require the use of distant tissue. Traditionally, nasal reconstruction has been carried out with a variety of forehead flaps. In recent years, there has been more acceptance of immediate repairs following the removal of these tumors. As a result, patients are more willing to undergo these extensive resections to improve their chances of cure, with the reasonable expectation that an immediate reconstruction will provide an adequate cosmetic result. Authors experienced 13 cases of head and neck tumor during last three and half years that required wide excision and immediate reconstruction with various flaps, not with primary closure or simple skin graft. We present our experience with varied flaps for reconstruction after wide resection of head and neck tumors 3 cases of defect of dorsum of nose or medial canthus with island forehead flaps, lower eyelid defect with cheek flap, cheek defect with Limberg flap, orbital floor defect with Temporalis muscle flap, lateral neck defects with Pectoralis major myocutaneous flap or Latissimus dorsi myocutaneous free flap, subtotal nose defect with scalping flap, wide forehead defect with Dorsalis pedis free flap and 3 cases of mandibular defect or mandibular defect combined with lower lip defect were reconstructed with free vascularized iliac bone graft or free vascularized iliac bone graft concomitantly combined with free groin flap pedicled on deep circumflex iliac vessels We obtained satisfactory results coincided wi th goal of treatment of head and neck tumors, MAXIMAL CURE RATE with MINIMAL MORBIDITY, OPTIMAL FUNCTION, and an APPEARANCE as close to normal as possible.

• Journal of the HCI Society of Korea
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• v.1 no.2
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• pp.9-17
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• 2006

We propose an EMG-based input interface technology for helping the tetraplegic to utilize mouse, keyboard and power wheelchair. Among possible actions for the tetraplegic utilizing these devices, teeth-clenching is chosen as an input action. By clenching left, right or both teeth, and controlling the clenching duration, several input commands for utilizing the devices can be conducted. EMG signals generated by teeth-clenching are acquired around one's left and right temples and they are used as control sources for utilizing the devices. We develop signal acquisition devices, signal processing algorithms, and prototype systems such as power wheelchair control, mouse control, and game control. Our experimental results with the tetraplegic show that the proposed method is useful for utilizing the devices.

• Journal of Korean Neurosurgical Society
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• v.67 no.2
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• pp.249-256
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• 2024

The Leksell frame-based transcerebellar approach was proposed with the arc support frame attached upside down to the Z coordinate. This study presented practical tips and considerations for obtaining adequate tissue samples for deep-seated cerebellar lesions or lower brainstem lesions specifically those accessible via the cerebellar peduncle. For practical insights, the Leksell coordinate frame G was fixed to prevent the anterior screw implantation within the temporalis muscle, to avoid interference with the magnetic resonance (MR)-adapter, and taking into account the magnetic field of MR in close proximity to the tentorium. After mounting of indicator box, the MR imaging evaluation should cover both the indicator box and the infratentorial region that deviated from it. The coordinates [X, Y, Za, Arc⁰, Ringa⁰] obtained from Leksell SurgiPlan^® software (Elekta, Stockholm, Sweden) with arc 0⁰ located on the patient's right side were converted to [X, Y, Zb=360-Za, Arc⁰, Ringb⁰=Ringa⁰-180⁰]. The operation was performed in the prone position under general anesthesia in four patients with deep cerebellar (n=3) and brainstem (n=1) tumors. The biopsy results showed two cases of diffuse large B-cell lymphoma, one metastatic braintumor and one glioblastoma. One patient required frame repositioning as a complication. Drawing upon the methodology outlined in existing literature, we anticipate that imparting supplementary expertise could render the stereotactic biopsy of infratentorial tumors more consistent and manageable for the practitioner, thereby facilitating adequate tissue samples and minimizing patient complications.

• The korean journal of orthodontics
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• v.27 no.2
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• pp.283-296
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• 1997

Stomatognathic system is a complex one that is composed of TMJ, neuromuscular system, teeth and connective tissue, and all its components are doing their parts to maintain their physiological relationships. Mandible, in particular, performs various functions such as mastication, speech, and deglutition, the muscular activities that determine such functions are signalled by numerous types of proprioceptors that exist in periodontal membrane, TMJ, and muscles to be controlled by complicated pathways and mechanics of peripheral and central nervous system. Orthodontic treatment, especially when accompanied by orthognathic surgery, brings dramatic changes of stornatognat is system such as intraoral proprioceptors and muscle activities and thus, changes in patterns of mandibular function result The author tried to analyze changes in patterns of mandibular movement and physiologic activities of surrounding muscles in Skeletal Class III ortlrognathic surgery patients who presently show a great increase in numbers. The purpose of this study was to draw some objective guidelines in evaluating funclierual aspects of orthognathic surgery patients. Mandibular functional analysis using Biopak was performed for skeletal Class III prognathic patients who underwent IVRO(lntraoral Vertical Ramus Osteotmy), and the following results were obtained: 1. Resting EMG was greater in pre-surgical group than the control group, and it showed gradual decrease after the surgery. Clenching EMG of masseter and anterior temporalis of pre-surgical group was smaller than those of control group, they also increased post-surgically, and significant difference was found between pre-surgical and post-surgical(6 months) groups. 2. Resting EMG of anterior ternporalis was greater than that of all the other muscles, but there was no significant difference. Clenching EMG of anterior temporalis and masseter were greater than those of the other muscles with statistical difference. In swallowing, digastric muscle showed the highest EMG with statistical significance. 3. Limited range of mandibular movement was shown in pre-surgical group. Significant increase in maximum mouth opening was observed six months post-surgically, and significant increase in protrusive movement was observed three months post-surgically.

• Journal of Korean Neurosurgical Society
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• v.29 no.8
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• pp.985-994
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• 2000

Objective : There are some advantages of trigeminal evoked potential(TEP) recording compared to other somatosensory evoked potential(SSEP) recordings. The trigeminal sensory pathway has a pure sensory nerve branch, a broader receptive field in cerebral cortex, and a shorter pathway. Despite these advantages, there is little agreement as to what constitutes a normal response and what wave forms truly characterize the intraoperative TEP. This study presents the normative data of TEP recorded on the epidural surface of the rat with a platinum ball electrode. Materials & Methods : Under general anesthesia with urethane, the adult Sprague-Dawley male rats(300-350g) were given electrical stimulation with two stainless steel electrodes which were inserted into the subcutaneous layer of the area around whiskers. A reference electrode was positioned in the temporalis muscle ipsilateral to the recording site. Results : TEPs were recorded in the Par I area of somatosensory cortex and recorded most apparently on the point of 2mm posterior from the bregma and 6mm lateral from the midline. The typical wave form consisted of 5 peaks (N1-P1-N2-P2-N3 according to emerging order, upward negativity). Each latency to corresponding peaks was not influenced by the different intensities of stimulation, especially from 1 to 5mA. Average latencies of 5 peaks were in the following order ; 7.7, 11.1, 15, 22.3, 29.4ms. There was also no significant difference between latencies before and after administration of muscle relaxant(pancuronium). For the electrophysiological localization of recorded waves, the action potential of a single unit was recorded with glass microelectrode(filled with 2M NaCl, $3-5M{\Omega}$) in the thalamus of rat. A sharp wave was recorded in the VPM nucleus, in which the latency was shorter than that of N1. This suggests that all 5 peaks were generated by neural activities in the suprathalamic pathway. Conclusion : In terms of recording near-field potentials, our data also suggests that TEP in the rat may be superior to other SSEPs. In overall, these results may afford normative data for the studies of supratentorial lesions such as hydrocephalus or cerebral ischemia which can have an influence on near-field potentials.

• Journal of Oral Medicine and Pain
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• v.33 no.1
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• pp.85-95
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• 2008

The purpose of this study was to evaluate the effects of oral habits on the muscles of mastication and facial expression by means of two parameters: muscle stiffness and elasticity. 10 healthy, fully-dentate male subjects in their twenties were selected for this study; all had normal Class I occlusal relationships. Muscle stiffness and elasticity were measured with a tactile sensor(Venustron, Axiom Co., JAPAN) while subjects were asked to relax and perform various parafunctional activities such unilateral clenching(biting the bite force recorder with a force of 50kg on each subject's preferred side), jaw thrusting and lip bracing. The following muscles were examined: temporalis anterior(Ta), masseter(Mm), frontalis(Fr), inferior orbicularis oculi(OOci), zygomaticus major(Zm), superior and inferior orbularis oris(OOrs and OOri) and mentalis(Mn). Paired t-test, Correlation Coefficients, ANOVA and Multiple Comparison t-tests were used for statistical analysis. Unilateral clenching was highly correlated with bilateral stiffness and elasticity of all the muscles tested. Mm was affected by all three oral habits; Ta was affected by unilateral clenching(p<0.05); Zm was affected by unilateral clenching and OOrs, OOri and Mn were most affected by lip bracing(p<0.05). This study indicates that not only the masticatory muscles but also the muscles of facial expression, mainly circumoral muscles, can be significantly influenced by parafunctional activities such as unilateral clenching and lip bracing.