• Journal of Dental Rehabilitation and Applied Science
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• v.32 no.3
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• pp.224-231
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• 2016

Severe dental attrition causes pathological changes of the tooth, imbalanced occlusion, and functional and aesthetic complications and can also result in a decrease in occlusal vertical dimension that can incur temporomandibular joint and muscular complications. Before restoring the vertical dimension with full-mouth prosthetic restorations, it is important to determine the amount of vertical lifting through complete diagnosis. In this study, a 59 year-old male patient with generalized attrition and fracture of teeth was treated with full-mouth zirconia prosthetic restoration in order to recover vertical dimension and aesthetics. Through the analysis of physiologic rest position and inter-canine distance, the treatment was planned for lifting 3 mm in vertical dimension. Interim crown were fabricated after full-mouth wax up, having the patient use for 6 months. The final monolithic and bilayered zirconia restorations were completed. The patient showed satisfaction in function and aesthetics for 18 months of follow-up since delivering the final restorations.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.6
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• pp.535-544
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• 2005

The management of mandibular condyle fractures continues to be a subject of much debate. It is suggested that, if not properly managed, these fractures may give rise to serious problems, such as malocclusion, mouth opening limitation, temporomandibular joint disorders. Treatment planing of mandibular condyle fractures is very important. The aim of this present study was to evaluate the long-term results according to treatment methods in condylar fractures. Also, it was to evaluate results of treatment according to condylar fracture level. We conducted a retrospective analysis of 43 mandibular condyle fractures. 43 patients followed for average period of 9.00 years(mini. 7yr, max. 12yr). All patients underwent a clinical and radiologic evaluation focusing on mouth opening, mandibular movements, TMJ function, change of ramal height, condylar remodelling. If the level of fracture was positioned in high, especially in level II, mandibular movement disability and ramus length loss was more prominent. This results were similar to the cases of treatment of fragment removal. In high level fracture and fragment removal cases, It is thought that more intensive and long term management are needed than other treatment cases using different operation methods. Also, direct fixation by each approach showed good results in mandibular movement, ramal height change and condylar shape. Through this results, accurate reduction of the mandibular condyle fractures was a very important factor in postoperative prognosis.

• Journal of Dental Rehabilitation and Applied Science
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• v.27 no.2
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• pp.223-231
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• 2011

The purpose of this case report is to introduce new attachment system(milled titanium bar with $Locator^{(R)}$ attachment) for implant supported overdenture in maxillary edentulous patients. A 56-years-old male patient visited the hospital due to the mobility of his maxillary fixed partial dentures(10-unit bridge). Including temporomandibular joint(TMJ), there was no specific PMHs to influence dental treatment. In radiographic and clinical evaluation, there was a severe bone resorption and mobility in maxillary teeth. Accordingly all the remaining maxillary teeth was extracted and fabrication of implant supported overdenture was planned. The milled titanium bar with $Locator^{(R)}$ was designed as an attachment system, considering the stability and retention of denture, masticatory efficiency, oral hygiene care, esthetics, pronunciation, and patient's financial state. The milled titanium bar was manufactured using CAD/CAM technology, and $Locator^{(R)}$ attachment connected to the bar by tap & drill method. For over 1-year, in terms of function and esthetics, satisfactory result was obtained.

• The Journal of Korean Academy of Prosthodontics
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• v.27 no.2
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• pp.189-200
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• 1989

The purpose of this study was to investigate the muscle activity of the group function occlusion and the changed canine guided occlusion using EM2. In this study, 13 subjects with group function occlusion and without temporomandibular disorders were selected, each subject was changed to the canine guided occlusion by forming the lingual ramps in the upper canines with light curing composite resin. The muscle activities of the anterior temporal and masseter muscle were recorded in the group function occlusion and immediately, one week, and two weeks after changing to the canine guided occlusion under the condition of maximum voluntary clenching in centric occlusion, lateral excursion, and during gum chewing. The results were as follows: 1. In case of maximum voluntary clenching in centric occlusion, the muscle activities of the anterior temporal and masseter muscle of working and balancing side didn't show any difference immediately after changing to the canine guided occlusion, one week after changing to the canine guided occlusion, one week after changing to it the muscle activities of the anterior temporal masseter muscle of working and balancing side were increased significantly, and two weeks after changing to it the muscle activities of the masseter muscle were increased significantly in comparison with the group function occlusion. 2. In case of maximum voluntary clenching in lateral excursion, the muscle activities of the anterior temporal and masseter muscle of working and balancing side were reduced significantly immediately after changing to the canine guided occlusion, one week after changing to it the muscle activities of the anterior temporal muscle of balancing side and of the anterior temporal and masseter muscle of working side were reduced significantly, and 2 weeks after changing to it the muscle activities of the anterior temporal and masseter muscle of working side were reduced significantly in comparison with the .group function occlusion. 3. During gum chewing, the muscle activities of the anterior temporal and masseter muscle of working and balancing side didn't show any difference immediately after changing to the canine guided occlusion, one week after changing to it the muscle activities of the masseter muscle of working and balancing side were increased significantly, and two weeks after changing to it only the muscle activities of masseter muscle of working side were increased significantly.

• Journal of Dental Rehabilitation and Applied Science
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• v.36 no.2
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• pp.80-87
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• 2020

Purpose: This study aims to measure the mandibular movement using JT-3D system and provide a range of mandibular movement that can serve as a good reference for diagnosing the temporomandibular disorder. Materials and Methods: This study was conducted in 60 young male and female adults. The maximum opening and closing movement was recorded using JT-3D system, and by regarding 5 times of repetitive movement as 1 cycle of movement, total 3 cycles of movement were recorded. During the maximum opening, vertical position of lower jaw, antero-posterior position, lateral deflection position, and maximum opening distance were recorded. To evaluate the reproducibility of JT-3D system, statistical analysis were conducted (α = 0.05). Results: During the maximum opening, the average value appeared at 31.56 mm vertically and 24.42 mm rearwardly, lateral deflection position 0.72 mm, and maximum opening distance 40.32 mm. There was no statistical significance in all measured values for three cycles of movement recorded with JT-3D system (P > 0.05). Conclusion: During the maximum opening, the average value appeared at 0.72 mm in lateral deflection position and the maximum opening distance at 40.32 mm, and the analysis on the maximum opening of lower jaw using JT-3D system showed sufficiently reproducible results.

• Journal of Dental Rehabilitation and Applied Science
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• v.26 no.2
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• pp.157-168
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• 2010

Many athletes have been using occlusal stabilization appliances to improve their performance. Few studies have examined the benefits of such an appliance in golf. We determined the effect of such appliances on the masticatory muscle activities and driving distances of professional golf players. The appliances were customized for each player and adjusted using a computerized device. The electromyographic muscle activities and driving distances with and without the appliance were measured and compared using the K7 Analyzer and the GolfAchiever II assembly. A paired t-test was used for statistical analysis. The muscle activities of the temporo-frontal and masseter muscles with the appliance were significantly more stable than those without the appliance, and the driving distances with the appliance were significantly different from those without it. Although there were intra-individual differences, professional golf players with temporomandibular disorders showed a greater improvement in performance.

• Journal of Dental Rehabilitation and Applied Science
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• v.24 no.1
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• pp.29-40
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• 2008

The purpose of this study was to evaluate the prevalence of symptoms and signs of temporomandibular joint dysfunction (TMD) and malocclusion in 10-12 year old children and to determine if a relationship exists between symptoms and signs of TMD and malocclusion. The subjects were composed of 465 school children (233 boys and 232 girls). Each subject was evaluated with simplified questionnaire and clinical examination to measure symptoms and signs of TMD and malocclusion. The results showed an elevated prevalence of headache (34.6%), which were more frequent in girls than boys. The most common cardinal sign of TMD was clicking (32.9%), which increased with age. TMJ lateral tenderness was present in 18.1% of the subjects and had a tendency to increase with age. Masseter muscle tenderness was found to be sensitive in 15.1%of the subjects and had a tendency to increase with age. Restriction of mandibular mobilitywas present in 30.3% of the subjects and had a tendency to increase with age. There was no significant difference in the prevalence of TMD signs between sex. The occlusal status showed Class I malocclusion in 73.3%, Class III in 12.9%,Class II division 1 in 11%, Class II division 2 in 2.8%. There was no significant difference in malocclusion traits between sex. There was statistically significant relationship between TMD signs and symptoms and class II division 1 and Class III malocclusion(p<0.05). The results indicate that the prevalence of TMD symptoms and signs in children is high, and the evaluation of TMD in children seems to be important.

• Journal of Oral Medicine and Pain
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• v.31 no.4
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• pp.347-354
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• 2006

Most patients suffering from TMD appear to have unsatisfactory masticatory function and compromised values of bite force. The purposes of this study were to investigate and compare bite force between affected and unaffected sides of patients with unilateral TMD and to evaluate its relation with duration of TMD. 42 patients with unilateral TMD, from Department of Oral Medicine, Dankook University Dental Hospital, were selected for this study. The ratio of men to women was 9:33 and their mean age of $27.2{\pm}10.4$ years. The bite forces were measured over both canines (for anterior bite force) and $1^{st}$ molars (for posterior bite force) using a bite force recorder while all the subjects were asked to clench successively for 3 seconds not until pain was felt. They were compared with those measured from bilateral TMD patients(N=6, M:F=1:5, mean age: $23.0{\pm}27.3$ years). The unilateral TMD patients were divided into time groups according to duration of TMD on the basis of 1 and 6 months, respectively. Paired and unpaired t-tests were used for statistical analysis. Unilateral TMD patients in this study showed that the affected sides had significantly lower bite force than the unaffected sides(force difference of about 7-8 kgf, p<0.05) while there was no significant sides difference in the bilateral patients. Nor did bite force on the affected sides reveal significant difference between unilateral and bilateral TMD patients. With regards to TMD duration, there was significant difference between the patients with TMD < 6 months and $\geq$ 6 months (p<0.05) while no significant difference existed between < 1 month and $\geq$ 1 month. The results of this study indicated that unilateral TMD patients can exhibit more reduced bite force on the affected sides compared with that on the unaffected sides and that bite force on the unaffected sides might be deteriorated more as longer did TMD last.

• Journal of Dental Rehabilitation and Applied Science
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• v.31 no.2
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• pp.86-95
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• 2015

Purpose: The aim of the study was to evaluate the subjective symptoms and clinical signs through the TMD-questionnaire, clinical examination and radiography against the many instrumental performers and to investigate the association between playing instruments and TMDs. Materials and Methods: A total of 803 instrumental performers received TMD-related questionnaire and evaluations of prevalence and disease distribution were performed. Among those who reported at least one symptom of TMD, 70 volunteers visited in clinic then received clinical examination and radiography for diagnosis and evaluations of prevalence and disease distribution were performed. 70 subjects were divided into three groups as woodwind, brass wind, string. Comparative analysis of disease distribution was performed. Results: Among 803 instrumental performers, 610 people (75.97%) were reported to one or more symptoms of TMD. The most frequent symptom was click (29.68%).70 subjects underwent a clinical examination and radiography survey results, the most frequent symptom was a click (29.75%). Most commonly diagnosed disease was a myofacial pain (30.53%).Comparison of the three groups, a significant difference was not observed in the clinical sign. But among subject symptom, muscle pains howed significant differences in accordance with the Group (P = 0.024). During the 70 people who underwent clinical examination, 66 people (94.3%) showed moderate to severe attrition, mild to severe tongue ridging, mild to severe cheek ridging assigns of parafunction. Conclusion: Instrumental performers showed a high prevalence of TMD and the most of the musicians with temporomandibular disorder had bruxism or clenching habits.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.3
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• pp.276-280
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• 2011

BSSRO (bilateral sagittal split ramus osteotomy) is an effective surgical method for maxillofacial deformities. Rigid fixation using a plate and screws can stabilize bony segments and induce early mouth opening. Though this procedure has a low complication rate, normal function and esthetic recovery is achieved through proper and early management of the complications. Complications consisting of temporomandibular disorders, sensory disturbances due to inferior alveolar nerve damage, open bite, malunion or nonunion, and facial nerve palsy occur, but these rarely develop. Facial nerve palsy causes the muscles involved in facial expression to depress, which results in ocular dryness or retinal damage. When facial nerve palsy develops, early management involving steroid medication and physical therapy is effective. In the case of severe damage, surgical intervention should be considered. A 20-year-male patient came to the oral and maxillofacial surgery department for orthognathic surgery. The mandible was set back by BSSRO under general anesthesia. Facial nerve palsy was observed on the left side of the face: steroid and vitamins were administered early and physical therapy was performed daily. These forms of management can aid in function and allow for gradual esthetic recovery. Presumed causes were excessive soft tissue retraction or soft tissue injury by the osteotome at the horizontal osteotomy of the ramus. Careful dissection, retraction and a precise osteotomy are needed for protection of the facial nerve. If nerve damage is observed, early management can help in the recovery of facial nerve function and esthetics.