• Maxillofacial Plastic and Reconstructive Surgery
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• v.35 no.4
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• pp.256-259
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• 2013

Botulinum toxin type A (BTX-A) inhibits muscle contraction, which leads to reversible muscle atrophy and paralysis. Therefore, BTX-A injection can be an effective treatment of facial asymmetry that originated from the uncoordinated muscle movement. A 52-year-old patient was referred from another hospital for the correction of post-traumatic sequelae. The patient had prominent scar in the mandibular symphysis area with asymmetric lower lip movement. The reason for this asymmetric lower lip movement was due to damage in the lower lip depressor muscle. After the injection of BTX-A on the lower lip depressors, asymmetric lip movement has been improved.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.27 no.6
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• pp.570-575
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• 2001

This study evaluated the short-term outcome of treating fractures of the mandible with bioabsorbable plates. Thirty-four fractures of the mandible in 27 patients were treated by open reduction and internal fixation using bioabsorbable plates and 2.4-mm, 2.0-mm, and 1.5-mm pre-tapped screws. The duration of intermaxillary fixation ranged from 0 to 23 days, with a mean of 5.3 days. Patients were evaluated for complications during the follow-up period, which ranged from 2 to 18 months. Five patients(18.5%) experienced complications. These included infection (four patients), and premature occlusal contact(one patient). Except for one case, all complications were minor and adequately managed with incision and drainage, elastic traction, and medication. Delayed infection (osteomyelitis) developed in a symphysis fracture and was treated by saucerization and antibiotics. The fracture line subsequently showed complete consolidation. Bioabsorbable plates can be selectively used for internal fixation in mandibular fractures with the advantage that they do not need to be removed.

• The Journal of Korean Academy of Prosthodontics
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• v.25 no.1
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• pp.195-204
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• 1987

The purpose of this study was to investigate the effect of occlusal splints on the masseteric silent period and the changes of the masseteric silent period after experimental bruxism with occlusal splints. In nine subjects, anterior occlusal splints were fabricated. The jaw-jerk reflex was induced by tapping over mandibular symphysis area with solenoid driven hammer and electromyogram of left masseter muscle was recorded. In the recorded electromyogram of left masseter muscle the silent period duration was measured. This procedure was done before insertion of anterior occlusal splints, after insertion of anterior occlusal splints, after 30 min experimental bruxism with anterior occlusal splints, and 3hr after removal of anterior occlusal splints. The result were as follows; 1. The mean silent period duration was increased after insertion of occlusal splints compared with the mean silent period duration before insertion of occlusal splints. 2. There was no change of the mean silent period duration after 30 min experimental bruxism with occlusal splints compared with the mean silent period duration after insertion of occlusal splints. 3. 3hr after the removal of occlusal splints, the mean silent period duration showed no difference from the mean silent period duration before insertion of occlusal splints.

• The Journal of Korean Academy of Prosthodontics
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• v.25 no.1
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• pp.205-212
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• 1987

The purpose of this study was to investigate the duration of the silent period of the masseter muscle in normal subjects after experimental bruxism. The material for this study consisted of 9 male subjects with an age range of 22-24 years who showed normal occlusion clinically and were free from any history or symptoms of temporomandibular joint dysfunction. A jaw-jerk was stimulated by tapping the mandibular symphysis during maximal voluntary clenching with a solenoid-driven hammer. And three separate silent period records were made from the left masseter muscle at the following times: at normal state, after experimental bruxism, 1 week after bruxism. The following conclusions were obtained: 1. The average value of the duration of masseteric silent period during maximal voluntary clenching was $33.62{\pm}1.86msec$ when tap force of approximate 650g was applied at normal state. 2. After experimental tooth grinding for 30 minutes, the duration of masseteric silent period increased to $46.29{\pm}4.40msec$. 3. Comparing the duration of silent period measured at normal state with that measured after 1 week, the duration of silent period showed reproducibility.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.17 no.3
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• pp.220-230
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• 1995

In this report, a case is presented in which resected mandible was reconstructed immediately with vascularized bone graft and adjunctive implantation of osseointegrated dental implants. The primary was central odontogenic myxoma of mandible extending from symphysis to the left condylar neck. The hemimandibulectomy defect was restored with free fibular flap. Three months after 1st surgery, the transplant received five $IMZ^{(R)}$ implants. The masticatory function was restored with the implant borne denture. The result including facial appearance was very satisfactory.

• Journal of radiological science and technology
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• v.32 no.3
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• pp.271-276
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• 2009

The aim of this study was to evaluate the effect of Bone Mineral Density(BMD) at mandible. So, we studied how to measure the BMD at mandible using DEXA(Dual energy X-ray absorptiometry, DEXA) by Horner er al (1996) and knew reproducibility of the measurements. Thirty-five patients (13 men, 22 women, mean age : 25.4 years) were examined using the GE Lunar Prodigy Advance(LUNAR Corporation, madison, USA). They were examined in Semiprone position of their body and true lateral position of their mandible selected the Lumbar lateral mode. We used the custom mode in analysis when ROI (area $30{\times}2.5\;mm^2$). Three ROIs ($30{\times}2.5\;mm^2$, $50{\times}2.5\;mm^2$, $20{\times}2.5\;mm^2$) were located each at the two different sites of the mandible (angle of mandible and mental symphysis) and BMD was measured. Differences in BMD measurement was statistically compared according to the size and location of ROI. BMD was $1.320{\pm}0.358g/cm^3$ in men and was $1.152{\pm}0.340g/cm^3$ in women. BMD at the angle of mandible was $1.201{\pm}0.361g/cm^3$ in men and was $1.025{\pm}0.377g/cm^3$ in women. BMD of men at the mental symphysis was $1.434{\pm}0.341g/cm^3$ and that of women was $1.19{\pm}0.358g/cm^3$. With the ROI of $20{\times}2.5\;mm^2$, BMD was $1.262{\pm}0.384g/cm^3$ in men and was $1.113{\pm}0.357g/cm^3$ in women. With the ROI of $50{\times}2.5\;mm^2$, BMD of men was $1.320{\pm}0.358g/cm^3$ and that of women was $1.129{\pm}0.340g/cm^3$. There was a statistically significant difference of BMD according to the size and location of ROI. When measuring mandible BMD, there are good for increasing ROI and locate between ramus and mental symphysis. Especially following exam, refer to same size and location with fore exam. According to study which measure mandible BMD, It's correct to measure better a portion of mandible then whole of BMD. Using DEXA protocol is studied good for the additional study to compare the BMD at mandible. Later date, It will be good for measurement value in implant and bone graft quantitatively. Using DEXA method gain BMD threshold value in korean.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.19 no.2
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• pp.167-180
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• 1997

79 surgically managed mandibular condylar fracture patients included the 25 patients treated with Dr, Nam's method were analysed the postoperative resluts in Oral and Maxillofcial Surgery, School of Dentistry, Wonkwang University since 1993 to 1995. Mean patient's age is 32.5 years (range, 8 to 65 years), and follow-up periods were a minimum of 3 months to 28 months. 19% condylar fractures were associated with mostly symphysis portion. According to the patient's age, severity of condylar fractures, clinical signs and symptoms, radiographic findings, treatmenet plans had been performed. Rigid fixation have performed greatly, and then fragment removal of fractured mesial pole of proximal segment of the condylar and little cases of reshaping and eminoplasty and lag screw have been applied. Two cases of the both condylar resorption and deviated condyle posteriorly in Dr. Nam's method. None of infection or necrosis signs of treated condyle surgically. In my opinion, whenever possible, displaced condylar fracture can be managed surgically with rigid fixation, but not Dr. Nam's method. Usually if perform the surgical management of condylar fractures you should maintain maxillomandibular fixation for 2 weeks, or more and has to follow-up functional mandibular exercise should be kept continuously.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.11 no.1
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• pp.50-62
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• 1989

This is clinicostatistical study of mandibular fractures. This study was based on a series of 677 patients with mandibular fracture during the period of 1982 to 1987. This results obtained were as follows : 1. In respect of incidence, there were high frequency in May and September, and in large city(63%). 2. The age frequency was the highest in the 20s-year old group (38.7%), and the ratio of male to female was 4.64 : 1. 3. The most common etiologic factor was blow(31.5%), but in children that was traffic accident followed by fall down. 4. The most common site of bone fractures was symphysis, followed by angle, condyle. In comparison of right and left sides, left side was more frequently involved(364 cases) than right side(257 cases). 5. The patients arrived in hospital immediately within 24 hours after accident were 62.9% of all, and 42.4% was arrived via private medical and dental clinic. 6. In respect of treatment, open reduction was 55.5% of all, closed reduction was 37.2%. In children, closed reduction was done in 50.6%.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.23 no.2
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• pp.155-162
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• 2001

This is a clinical study on patients who had visitied the Emergency Room of Pusan National University Hospital and then been treated in the Department of Oral and Maxillofacial Surgery during recent 5 years, from 1992 to 1996. The results were as follow ; 1. The total number of patients was 2,680 and the ratio of male to female was 1.96:1, The highest monthly incidence was shown in September(12.1%) and October(10.5%) and the age distribution peaks was the third decade(24.3%), followed by the first(23.1%) and the fourth decade(17.2%). 2. Soft tissue injury group(29.1%) was the most prevalent, followed by tooth injury group(16.1%), facial bone injury group (16.0%), toothache group(11.2%), socket bleeding group(11.1%), infection group(9.8%) and TMJ dislocation group(5.9%). 3. The percentage of in-patients and out-patient were 21.6% and 78.4%, respectively. The frequent causes of admission were facial bone fracture(73.8%), infection(20.8%) and soft tissue injury(4.8%) in order. However, soft tissue injury was the most frequent cause in out-patient, followed by tooth injury(20.5%), toothache(14.3%), socket bleeding(14.2%) and TMJ dislocation(7.6%). 4. In the facial bone injury group, the mandibular fractures(70.6%) showed the highest incidence, followed by zygomatic bone and arch fractures(7.5%), maxillary bone fractures(4.0%) and nasal bone fractures(4.0%). 5. In the mandibular bone fracture, the most common location was symphysis(36.7%), followed by the mandibular angles(33.1%) and the condyles(21.8%). 6. The common causes of facial bone fractures were violence, fall and traffic accident in order. 7. The common causes of soft tissue injury were fall down, fight and traffic accident in order and the highest incidence was observed in infants before the age of 10 years(44.0%). 8. In the group of tooth injury, tooth luxation(38.5%) showed the highest incidence followed by tooth fracture(33.2%) and tooth loss(17.1%). The common causes of tooth injury were fall, fight and traffic accident in order. 9. In infected patients group, the ratio of in-patients to out-patients was 1 : 1.28, Buccal(24,7%) and infraorbital space abscess(23.3%) showed the highest incidence. 10. The pain caused by dental caries(39.0%) and pericoronitis(26.6%) showed high incidence in the toothache group. 11. The high incidence was observed during third(34.0%) and fourth (24.5%) decades in TMJ dislocation group. 12. In the group of socket bleeding patients, 92% was post-operative hemorrhage and 8% was accompanied with other systemic hemorrhagic diseases.

• Journal of Dental Rehabilitation and Applied Science
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• v.17 no.4
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• pp.245-256
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• 2001

The purpose of this study is to analyze the mechanical stress and displacement on the jaws during the simulated bilateral clenching task on the three-dimensional finite element model of the dentated skull with unilateral molar loss. For this study, the computed tomography(G.E.8800 Quick, USA) was used to scan the total length of human skull in the frontal plane at 2.0mm intervals. The fully assembled finite element model consists of the articular disc, maxilla, mandible, teeth, periodontal ligament and cranium. The FE model was used to simulate the bilateral clenching in intercuspal position. The loading condition was the force of the masseter muscle exerted on the mandible as reported by Korioth et al. degrees of freedom of the zygomatic region where the masseter muscle is attached were fixed as restraints. In order to reflect the actual action of the muscles force, the displacement of the region was attached where the muscle is connected to the temporal bone and restraint conditions were given values identical to values at the attachment region of the masticatory muscle but with the opposite direction of the reaction from when the muscle force is acted on the mandible. Although the mandible generally has higher displacement and von Mises stress than the maxilla, its mandibular corpus on the molar-loss side has a higher stress and displacement than the molar-presence side. Because the displacement and von Mises Stress was the highest on the lateral surface of mandibular corpus with molar loss, the stress level of the condyle on the molar-loss side is greater than that of the molar-presence side, which in turn caused the symphysis of the mandible to bend. In conclusion, the unilateral posterior bite collapse with molar loss under para-functional activities such as bruxism and clenching can affect the stress concentration on the condyle and mandibular corpus. It is therefore necessary to consider the biomechanical function of dento-skeleton under masticatory force while designing the occlusal scheme of restoration on alveolar bone with the posterior collapse.