• Journal of Oral Medicine and Pain
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• 제17권1호
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• pp.61-71
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• 1992

52 Dental students without masticatory problems were selected for this study. They were trained on several mandibular position and mandibular movement exercise, that is, rest position, light bite, tapping, hinge opening, habitual opening, opening limitation, stretch exercise, resistance exercise and clenching. The objectives of this study was to investigate the effects of mandibular movement exercise, especially stretch and resistance, on the experimentally guided limited mouth opening. Muscle activity of the anterior temporalis and the masseter on above mentioned position or exercise were recorded with bioelectric processor EM2(Myotronics, U.S.A.) and the data were processed with SPSS. The obtained results were as follows : 1. Activity of the muscles at rest position were decreased with mandibular movement exercise. 2. Forceful mouth opening on opening limitation increased muscle activity greatly, especially of the masseter. 3. On opening limitation, stretch or resistance exercise was very efficient for decrease of muscle activities. 4. There were no difference of muscle activity between on hinge opening and on habitual opening. Therefore, for muscle relaxation, the two movement exercise can be used interchangeably.

• Journal of Oral Medicine and Pain
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• 제41권3호
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• pp.133-136
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• 2016

Facial abscess is a suppurative condition that is caused by infection and that its infected materials built up within the loose connective tissues or a fascial space of the head and neck. Facial abscess should be treated with a caution since it can make threat to patient's life. When pus collects near masticatory muscles, it may lead to masticatory muscle disorder reducing the range of mouth opening and the mobility of jaw. The authors review an uncommon case of facial abscess which occurred in temporal muscle and induced mouth opening limitation.

• Journal of the korean academy of Pediatric Dentistry
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• 제21권2호
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• pp.605-610
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• 1994

Resricted opening of the mouth in children can be derived from a variety af extra and intra articular causes. A 5-year-old female patient with an elongated right coronoid process and with congenital missing teeth came to clinic for wearing of esthetic denture. A proper medical consultation and laboratory test had done for assessment a systemic syndrome related to her dental anomalies. The result was that her systemic findings dindn't accord specific signs and symptoms of Hallermann-Streiff syndrome. Unilateral coronoidectomy was fulfilled to improve mouth opening and subsequently endodontic and restorative procedure. Maxillary partial denture was delivered for esthetic problem. The periodic recall medical/dental check-up are recommended.

• Journal of the Korean Society for Precision Engineering
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• 제11권2호
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• pp.134-140
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• 1994

Numerical caiculations are made in order to find a possible relation between the J-integral and the crack mouth opening displacement(CMOD) in dynamic nonlinear fracture experiments. Both elastic-plastic and elastic-viscoplastic materials are considered at different impact velocities. The J-integral may be estimated from the crack mouth opening displacement which can be measured directiy from photographs taken during dynamic experiments.

• Journal of the korean academy of Pediatric Dentistry
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• 제28권4호
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• pp.593-599
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• 2001

Recently, tempormandibular disorder(TMD) shows an tendency to increase every year. TMD is a collective term embracing a number of clinical problems that involve the masticatory musculature, temporomandibular joint(TMJ) and associated structures, or both. TMD, viewed in distribution of age, often occurred from late teens to late twenties. But recently, the age of occurrence tends to be lower. Accordingly, early diagnosis of tempormandibular disorder is very important. In this study, we measured the maximum mouth opening which is simple and easy to carry out as a way of TMD diagnosis. In this study, the maximum mouth opening was examined for 1,775 children from 4 to 12 years of age. We compared the relationship between the maximum mouth opening with the age, height, and weight. The results obtained were summarized as follows; 1. The mean maximum mouth openings of 4, 8, and 12 year of age were respectively 40.16mm, 47.32mm, 50.54mm for male, 39.79mm, 44.85mm, 48.09mm for female. 2. The maximum mouth opening increased with age, and the values were greater in male than in female. 3. The maximum mouth opening increased with height, and the values were eater in male than in female except between 105cm and 115cm 4. The maximum mouth opening increased with weight, and the values were eater in male than in female. 5. The correlation between the maximum mouth opening with the age, height, and weight was all significant, and height showed the highest correlation.

• Journal of Oral Medicine and Pain
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• 제23권4호
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• pp.447-455
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• 1998

A 42-year old male patient was referred to the Department of Oral Medicine, Kyungpook National University Hospital due to the chief complaint of limite mouth opening. Three years ago, the patient was diagnosed as an infarction of both cerefellar hemispheres, acute obstructive hydrocephalus and acute epidural hematoma of frontal lobe at the department of neurosurgery.Both of the infarcted cerevellar hemispheres and the epidural hematoma of frontal lobe were removed with suboccipital and frontal craniectomu. After the brain surgery jaw opening range was decreased progressively and ultimately mouth opening became almost impossible. Spasmodic and rhythmic contractions of the masseter muscles occurred intermittently during daytime as well as sleeping. Food intake was available only through Levin -tube. Actibe jaw opening exercise was prescribed with the aids of tongue blades. A moist hot pack and indomethacin phonophesis were also applied 20 minutes three times a day to decrease discomfort muscle activities. After a month of treatments, the opening range was increased to 5mm at the premolar area and oral food intake was possibel. The L-tube was removed and the patient was discharged.

• Journal of the Korean Society of Safety
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• 제19권2호
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• pp.16-20
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• 2004

This paper aims to analyze fatigue fracture mechnisms with high strength aluminum alloys, which are widely used in vehicles or airplanes to prevent accidents. Usefulness of the crack opening point was proposed by using an effective stress intensity facor when evaluating the fatigue crack propagaion rate. Therefore an exact crack opening ratio can be measured for a more exact fatigue crack propagation rate. It is found that the fatigue crack propagation rate was valid within the range of experimentation as an effective stress intensity factor. Summarizing the results are as follows in this paper ; (1) It is found that the value of the crack opening ratio is constant at the rear of the specimen, U'=0.25 at the crack mouth and U'=0.45 at the crack tip, respectively regardless of the stress ratio. (2) The crack opening ratio is different according to measurement locations. The crack opening ratio value was measured at the crack mouth by a clip gage or measured behind the specimen by a strain gage. It is found that the crack opening ratio value is more accurate that any other measuring test for evaluating the crack propagation ratio test by effective stress intensity factor.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제45권1호
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• pp.9-14
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• 2019

Objectives: This study aimed to evaluate the effect of clinical factors on the outcome of arthrocentesis in the treatment of temporomandibular joint (TMJ) internal derangement. Materials and Methods: Fifty patients with TMJ internal derangement underwent arthrocentesis using ringer's lactate. The present study evaluated the contribution of the clinical variables of age, time since onset, visual analogue scale (VAS) pain level, and range of motion (ROM) on the outcomes of TMJ arthrocentesis: age (${\leq}25\;years$, >25 and ${\leq}40\;years$, >40 and ${\leq}60\;years$), VAS pain level (${\leq}5$, >5 and ${\leq}7$, >7 and ${\leq}10$), and ROM (<25 and ${\geq}25mm$). Odds ratios (ORs) were used to describe the proportional benefit of each variable the on successful outcome of arthrocentesis. For the OR to be clinically relevant or even clinically noticeable, we assumed that the OR would need to be larger than 2. Results: Mean preoperative pain score was $6.49{\pm}1.560$ and at 6 months postoperative was $0.46{\pm}1.147$ with an average decrease of pain score 6 (P<0.001). The mean preoperactive maximum mouth opening was $26.14{\pm}4.969mm$ and mean maximum mouth opening at 6-month inerval was $38.92{\pm}3.392mm$. The mean increase in the mouth opening was a mean difference of 12.78 mm (P<0.001). Logistic regression showed that the maximum benefit occurred in patients aged <25 years (OR, 12.01; P=0.012), a VAS pain level of >7 (OR, 11.25; P=0.039), and a maximum vertical opening of <25 mm (OR, 7.70; P=0.038). Conclusion: Lavage of the superior joint space with ringer's lactate resulted in significant reduction in pain and improvement in mouth opening. Patients with a greater inflammatory component and younger patients benefitted more from arthrocentesis. Evaluation of these clinical variables helped in predictive modelling, which may provide clinicians with the opportunity to identify "at-benefit" patients early and initiate specific treatment.

• Imaging Science in Dentistry
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• 제32권2호
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• pp.113-118
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• 2002

Ankylosis of joint is defined as limited movement due to infection, trauma, or surgical procedure. A 59-year-old female with a chief complaint of limited movements during mouth opening had a positive history of trauma to her right TMJ area about 5 years ago. From that time, progressive mouth opening limitation and intermittent pain have occurred. At the time of admission the patient showed mandibular deviation to the right side during mouth opening, with a maximum opening limited to 5 mm. On plain radiographs, right condylar enlargement and joint space reduction by newly formed bony tissues were observed. CT scans showed right condylar enlargement, cortical sclerosis, and thickening of the condyle, articular fossa and articular eminence.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제44권4호
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• pp.191-197
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• 2018

Objectives: The objective of the study was to evaluate the results of nasolabial/extended nasolabial flaps as a modality for treatment of oral submucous fibrosis. Materials and Methods: Eleven patients of Stage III or IVa maximum interincisal opening were selected to be operated. Nasolabial/extended nasolabial flaps were done for both the sides. All of the flaps were done in a single stage and were inferiorly based. A similar flap harvest/surgical technique was utilized for all the cases. Results: The preoperative mouth opening ranged from 5 to 16 mm, with a mean of 10.09 mm. At 6 months the mouth opening ranged from 29 to 39 mm. Some of the complications encountered were poor scar, wisdom tooth traumatising the flap, decreased mouth opening due to non compliance and too much bulk. All of theses were managed satisfactorily. Conclusion: The nasolabial flap is a very reliable flap to restore the function of oral cavity. Important adjuvant measures are habit cessation, lifestyle changes, and aggressive physiotherapy.