• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.43 no.2
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• pp.134-137
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• 2017

Giant cell tumor (GCT) of the craniofacial bones has been reported but they are not common. This tumor occurs more often in women than in men and predominantly affects patients around the third to fifth decade of life. GCTs are generally benign but can be locally aggressive as well. We report a case of GCT involving the temporomandibular joint (TMJ), which was initially thought to be temporomandibular disorder (TMD). A 22-year-old female presented with swelling and pain over the right temporal region for 18 months associated with jaw locking and clicking sounds. On examination, her jaw deviated to the right during opening and there was a $2{\times}2$ cm swelling over the right temporal region. Despite routine treatment for TMD, the swelling increased in size. Computed tomography and magnetic resonance imaging of the brain and TMJ revealed an erosive tumor of the temporal bone involving the TMJ which was displacing the temporal lobe. Surgical excision was done and the tumor removed completely. Histopathological examination was consistent with a GCT. No clinical or radiological recurrence was detected 10 months post-surgery.

• The Journal of Korea Assosiation for Disability and Oral Health
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• v.11 no.2
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• pp.62-66
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• 2015

Temporomandibular joint dislocation causes considerable pain, discomfort, and swelling. The anatomic construction of the articular fossa and the eminentia articularis may predispose to dislocation, and weakness of the connective tissue forming the capsule is believed to be a predisposing factor. The capsule may be stretched and, more rarely, torn. Dislocation may be unilateral or bilateral and may occur spontaneously after stretching of the mouth to its extreme open position, such as during a yawn or during a routine dental operation. Manual reduction with the patient under muscle-relaxing condition or anesthesia is recommended method. After the reduction of an acute dislocation, immobilization of the jaw is recommended to allow the stretched and sometimes torn capsule to heal, thus preventing recurrence. A Barton's bandage may be applied for 2 to 3 weeks to prevent the patient from opening the jaw too wide. But, it results in recurrent dislocation in the neurologically disabled patient, because of loose intermaxillary fixation. This is a case report about management of recurrent temporomandibular joint dislocation by multiple loop wirings and intermaxillary elastics in cerebrovascular accident patient.

• Phonetics and Speech Sciences
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• v.2 no.4
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• pp.51-58
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• 2010

English vowels play an important role in the daily communication between Korean students and international visitors. However, many Korean students still have difficulty producing them distinctively. Vowels vary according to shapes of oral and pharyngeal cavities, which are mainly determined by the degree of jaw opening and tongue position. Yang (2008a) proposed a simplified chart of English and Korean vowels for an educational purpose. He also suggested to use wooden chopsticks to secure distinguishable jaw openings. The purpose of this study is to tap whether wooden chopsticks can be applicable to a method for correcting English vowel pronunciation. Twelve male and female students participated in the recordings of eight /hVd/ words followed by additional recordings with wooden chopsticks between upper and lower teeth. The first and second formant trajectories of both natural and controlled vowel productions were obtained and compared at six equidistant measurement points using Praat. Results showed that the formant values of natural vowel productions were comparable to those of controlled productions. Vowels with similar formant trajectories of male students were separated with the aid of chopsticks. The width of each chopstick could be controlled similarly in the experiment. The author concludes that wooden chopsticks can be useful to correct vowel pronunciation. Further studies are desirable for native speakers to make perceptual evaluations of controlled vowel productions by nonnative speakers.

• Phonetics and Speech Sciences
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• v.7 no.1
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• pp.151-163
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• 2015

In this study, we aim to describe kinematic characteristics of Korean /l/-flapping in two speech rates (fast vs. comfortable). Production data was collected from seven native speakers of Seoul Korean (four females and three males) using electromagnetic midsagittal articulometry (EMMA), which provided two dimensional data on the x-y plane. We examined kinematic properties of the vertical/horizontal tongue tip gesture, the vertical/horizontal (rear) tongue body gesture, and the jaw gesture in an /i/-/i/ context. Gestural landmarks of the vertical tongue tip gesture are directly measured. This serves as the actual anchoring time points to which relevant measures of other trajectories referred. The study focuses on velocity profiles, closing/opening spatiotemporal properties, constriction duration, and constriction minima were analyzed. The results are summarized as follows. First, gradiently distributed spatiotemporal values of the vertical tongue tip gesture were on a continuum. This shows more of a reduction in fast speech rate, but no single instance of categorical reduction (deletion). Second, Korean /l/-flapping predominantly exhibited a backward sliding tongue tip movement, in 83% of production, which is apparently distinguished from forward sliding movement in English. Lastly, there was an indication of vocalic reduction in fast rate, truncating spatial displacement of the jaw and the tongue body, although we did not observe positional variations with speech rate. The present study shows that Korean /l/-flapping is characterized by mixed articulatory properties with respect to flapping sounds of other languages such as English and Xiangxiang Chinese. Korean /l/ flapping demonstrates a language-universal property, such as the gradient nature of its flapping sounds that is compatible with other languages. On the other hand, Korean /l/-flapping also shows a language-particular property, particularly distinguished from English, in that a backward gliding movement occurs during the tongue tip closing movement. Although, there was no vocalic reduction in V2 observed in terms of jaw and tongue body height, spatial displacement of these articulators still suggests truncation in fast speech rate.

• The korean journal of orthodontics
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• v.49 no.4
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• pp.254-264
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• 2019

Objective: To evaluate the short-term changes in masticatory muscle activity and mandibular movement patterns after orthognathic surgery in skeletal Class III patients with facial asymmetry. Methods: Twenty-seven skeletal Class III adult patients were divided into two groups based on the degree of facial asymmetry: the experimental group (n = 17 [11 male and 6 female]; menton deviation ${\geq}4mm$) and control group (n = 10 [4 male and 6 female]; menton deviation < 1.6 mm). Cephalography, electromyography (EMG) for the anterior temporalis (TA) and masseter muscles (MM), and mandibular movement (range of motion [ROM] and average chewing pattern [ACP]) were evaluated before (T0) and 7 to 8 months (T1) after the surgery. Results: There were no significant postoperative changes in the EMG potentials of the TA and MM in both groups, except in the anterior cotton roll biting test, in which the masticatory muscle activity had changed into an MM-dominant pattern postoperatively in both groups. In the experimental group, the amount of maximum opening, protrusion, and lateral excursion to the non-deviated side were significantly decreased. The turning point tended to be shorter and significantly moved medially during chewing in the non-deviated side in the experimental group. Conclusions: In skeletal Class III patients with facial asymmetry, the EMG activity characteristics recovered to presurgical levels within 7 to 8 months after the surgery. Correction of the asymmetry caused limitation in jaw movement in terms of both ROM and ACP on the non-deviated side.

• Journal of Oral Medicine and Pain
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• v.38 no.4
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• pp.333-338
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• 2013

Purpose: A growing number of studies have been providing evidence for neural connections between the auditory and somatosensory systems that might be a critical part of the mechanisms underlying certain forms of tinnitus. The aim of this study was to investigate the effect of temporomandibular joint (TMJ) movements on tinnitus. Methods: One hundred sixty-three tinnitus patients participated in this study. All patients underwent a thorough audiological examination including pure-tone audiometry, tinnitus handicap inventory, and evaluation of tinnitus loudness, frequency and severity on a visual analog scale. Somatic testing consisting of nine forceful jaw muscle contractions was performed to evaluate the effect of TMJ movements on modulation of tinnitus. Results: 66.9% of patients had unilateral tinnitus. Somatic testing modulated tinnitus loudness in 125 ears (57.6 %) of 217 ears tested. An increase in tinnitus loudness was observed more often than a decrease. Loudness was most commonly increased by opening and clenching jaw. Tinnitus could be induced by opening, clenching and deviating jaw to the left. Conclusion: Our study showed evidence that TMJ movements may aggravate and even evoke tinnitus and somatic testing can be used for evaluating if stimulation of the TMJ induces or aggravates tinnitus.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.18 no.2
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• pp.298-307
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• 1996

Osteochondroma is a common benign tumor of the axial skeleton, especially the distal metaphysis of the femur and the proximal metaphysis of the tibia, however, is occurred rarely on the facial skeleton. Development of the tumor is most frequently seen in the second or third decades of life. Typically, it arises directly from the cortex of the underlying bone, without any intervening zone of abnormal osseous tissue, and is covered by a cap composed of cartilage undergoing calcification. In case of osteochondroma of the mandibular condyle, its clinical features are occulusal change, facial asymmetry, headache, pain and click on temporomandibular joint, mouth opening limitation, and jaw deviation to involved site. This is a case report of a 13-year old woman who had mouth opening limitation and severe temporomandibular joint pain. We obtained successful results with surgical removal of the osteochondroma on the mandibular condyle.

• Progress in Medical Physics
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• v.16 no.2
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• pp.70-76
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• 2005

For clinical implementation of Enhanced Dynamic Wedge (EDW), it is necessary to adequately analyze and commission its dosimetric properties in comparison to common physical metal wedge (MTW). This study was implemented with the essential measurements of parameters for clinical application, such as percentage depth dose, peripheral dose, surface dose, effective wedge factor, and wedge profile. In addition, through the comparison study of EDW with open and MTW, the analysis was performed to characterize the EDW. We also compared EDW dose profiles of measured values using chamber array 24 (CA24) with calculated values using radiation treatment planning system. PDDs of EDW showed good agreements between $0.2\~0.5\%$ of open beam, but $2\%$ differences with MTW. In the result of the measurements of peripheral dose, it was shown that MTW was about $1\%$ higher than open field and EDW. The surface doses of $60^{\circ}$ MTW showed 10% lower than the others. We found that effective wedge factor of EDW had linear relationships according to Y jaw sizes and was independent of X jaw sizes and was independent of X jaw sizes and asymmetric Y jaw opening. In comparison with measured values and calculate values from Golden-STT based radiation treatment planning system (RTP system), it showed very good agreement within difference of $1\%$. It could be concluded that EDW is a very reliable and useful tool as a beam modification substitute for conventional MTW.

• Journal of Oral Medicine and Pain
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• v.31 no.1
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• pp.69-77
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• 2006

Botulinum toxin injection has been used in the masticatory muscle area as an effective treatment method of various movement disorders and facial contouring, but its effects on jaw function have not been evaluated. The aims of this study were to evaluate the effects of botulinum toxin type A injection into the masseter muscle on the EMG activities of masseter and anterior temporal muscles, and the limitation of jaw function. Fourteen healthy subjects were recruited. Five subjects were injected with 80 units of botulinum toxin type A(Dysport, Ipsen, Wrexham, UK) into each side of masseter muscle, and nine subjects were injected with saline into the same site as the botulinum toxin group. The surface EMG activities at maximum voluntary contraction of masseter and anterior temporal muscles were recorded before, 1 week, 2 weeks, and 3 weeks after injection. Presence of jaw functional limitations in each subject was investigated using Korean version of Jaw Functional Limitation Scale(JFLS) questionnaire. The masseter muscle EMG was gradually decreased in the botulinum toxin group comparing with that of the control group(p<0.001), but the anterior temporal muscle EMG did not show significant changes. There was significant increases in the mastication (p<0.01), and global jaw limitation(p<0.05) subscales of JFLS at 1 week after injection, but no significant changes in the other subscales including opening, and verbal and emotional expression during the recording periods. Our results suggest that botulinum toxin injection into masseter muscle can affect modest limitation in mastication function at 1 week after injection but recovered to the baseline until 3 weeks after injection. The EMG activity of masseter muscle had been gradually decreased until 3 weeks after botulinum toxin injection but the anterior temporal muscle did not show any significant changes.

• The Journal of Korean Academy of Prosthodontics
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• v.36 no.3
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• pp.427-452
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• 1998

To elucidate the effects of food texture such as hardness, cohesiveness, adhesiveness on mastication procedure, the electromyographic activity (EMG) of the masticatory muscles and the chewing movements were analyzed in eighteen young subjects during ordinary chewing. Seven different foods were selected by sensory texture profiling and mechanical test with texturometer; egg white, sausage, pizza cheese, yang-geng, biscuit, peanut and almond. The indexes of jaw movements used were the chewing number, chewing time, maximum opening, average opening, closing velocity and opening velocity. The EMG indexes analyzed were maximum and average integrated amplitude of the anterior temporal and masseter muscles. The results obtained were as follows. 1. The chewing time and chewing number, mandibular displacement and mandibular movement velocity were not changed by the hardness, cohesiveness and adhesiveness of the food (p>0.05). 2. The harder food materials showed a higher amplitude of the anterior temporal muscle integrated EMGs than the softer ones (p<0.05). 3. The maximum and average integrated EMGs of the masseter muscle increased with the increase of hardness of the food (p<0.05). 4. The integrated EMGs of preferred side and non-preferred side masticatory muscles increased with the increase of hardness of the food (p<0.05). 5. The adhesiveness and cohesiveness of the food were not the determining factor to the integrated EMGs of masticatory muscles (p<0.05).