• The korean journal of orthodontics
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• v.48 no.2
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• pp.90-97
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• 2018

Objective: The aim of this study was to assess the analgesic effect of a single application of low-level laser therapy (LLLT) on spontaneous pain and pain on chewing after placement of initial archwires. Methods: Forty-two patients (26 women, 16 men) were randomly recruited for this split-mouth randomized clinical trial. Each patient received super-elastic nickel-titanium (NiTi) initial archwires (0.012, 0.014, 0.016, and 0.018-inch [in]) in the maxilla for leveling and alignment for an interval of 4 weeks between archwires. One side of the mouth was randomly designated as experimental, while the other side served as placebo. After insertion of each archwire, the experimental side was irradiated with a diode laser for 3 seconds each on 5 points facially and palatally per tooth, from the central incisor to first molar. On the placebo side, the laser device was held the same way but without laser application. A numerical rating scale was used to assess the intensity of spontaneous and masticatory pain for the following 7 days. The Mann-Whitney U test was used to compare pain scores between sides. Results: Patients in the LLLT group exhibited significantly lower mean scores for spontaneous pain after insertion of the initial two archwires (0.012-in and 0.014-in NiTi; p < 0.05), while there was no significant difference for 0.016-in and 0.018-in wires between the LLLT and placebo groups. LLLT significantly reduced chewing pain scores (p < 0.05) for all archwires. Conclusions: A single dose of LLLT considerably lessened postoperative pain accompanying the placement of super-elastic NiTi wires for initial alignment and leveling.

• The korean journal of orthodontics
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• v.44 no.3
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• pp.143-153
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• 2014

An 8-years old boy with facial asymmetry and unilateral posterior crossbite on the left side received orthopedic and orthodontic treatment. During the first phase of treatment, the narrow maxillary arch was expanded using an acrylic plate. Then, the acrylic plate was used as a bite block with occlusal indentations from the construction bite that was obtained with the incisors in a coincident dental midline. After the position of the mandible was stabilized, the second phase of orthodontic treatment was initiated using fixed appliances for detailing of the occlusion. Skeletal symmetry, ideal occlusion, and coincident dental midlines were thus achieved. Functionally, occlusal force balance and masticatory muscle activity were improved, and the chewing patterns were normalized.

• 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 Oral Medicine and Pain
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• v.23 no.2
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• pp.127-141
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• 1998

This study was performed to investigate the clinical features of internal derangement of temporomandibular joint. For this study, 117 patients with temporomandibular disorders and 81 dental students without any signs and symptoms of temporomandibular disorders were selected as the patients group and as the control group, respectively. Preferred chewing side, Angle's classification, lateral guidance pattern, maximal mouth opening range, and affected side were recorded clinically. Head and shouldeer posture was measured in a groundplate on which square diagram of five centimeters each had been drawn, and cephalograph was also taken for measurement of head and neck posture. Sonopak of Biopak system (Bioresearch inc., USA) was used to record joint vibration for evaluation of internal healthy status of temporomandibular joint. The data collected were analyzed by SAS statistical program. The results of this study were as follows : 1. Frequency of left side chewing subjects was higher in patients than in control group, but there was no difference in distribution of subjects by Angle's classification. Other types was prvalent in patients whereas group function was more in control group for lateral guidance pattern. 2. As to lateral guidance pattern by clinical diagnosis, patients with internal derangement and/or degenerative joint disease showed higher frequency was consistent with the result by Sonopak impression. 3. There was no difference for shoulder height between the two groups, however, tilting of head and backward extension of cervical spine was more frequent in control group. 4. Acromion was positioned more anteriorly in patients with internal derangement and/or degenerative joint disease than in control group and angle between eye and tragus was larger in patients. Patients with degenerative joint disease showed more flexed head posture than control group did in cephalometric profile. 5. Maximal mouth opening range in patients with internal derangement was the least in all subgroups in patients classified by Sonopak impression.

• The Journal of Korean Academy of Prosthodontics
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• v.32 no.3
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• pp.431-443
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• 1994

As the dental arch is the curve connecting the cusp tip of tooth, the dental arch form, composing of the occlusion, is one the important factors of occlusal reconstruction. Many studies about the horizontal dental arch form have been reported, but until now, it is unclear to infer the position of the teeth in dental arch form, to evaluate the effect of the horizontal dental arch form on chewing movement. The purpose of this study is to make objective criteria to infer the position of the teeth in dental arch. In this study, 100 subjects with individdual normal occlusion were evaluated. By multiple regression analysis on the basis of the relation of the canine and the first molar, the positions of teeth in dental arch were inferred. According to buccolingual relationship of maxillary to mandibular posterior teeth, the dental arch forms were classified into five groups, i, e. the normal group, the group which the maxillary second molar positions buccal side, the group which the maxillary premolars position buccal side, the group which the maxillary premolar position lingual side. From the results, objective criterial to infer the positons of the first premolar, the second premolar, the second molar in dental arch were made.

• 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.

• The Journal of Korean Academy of Prosthodontics
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• v.35 no.1
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• pp.15-29
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• 1997

The author performed this study to investige the relationship between condylar movements recorded with Pantronic and mandibular movements at incisal area recorded with BioEGN. For this study 24 patients with Temporomandibular disorders(TMDs) and 30 dental students without any masticatory symptoms were selected as patients group and control group, respectively. The items recorded with Pantronic(Denar Corp., USA) were immediate side-shift, orbiting path, protrusive path, and PRI. BioEGN(Bioelectric-gnathography, Bioresearch Inc., USA) were sued to measure the amount of mandibular torque movement in frontal and horizontal plane and also the distance of mandibular translation at incisal area. Amount of mandibular rotational torque movement was analyzed by angle and difference between both condyles in frontal and horizontal plane. The collected data were processed with SAS program and conclusion were as follows : 1. Mean value of items recorded with Pantronic were not significantly differed between patients group and control group except the item of pantographic reproducibility index(PRI). The value of PRI was 39.5 in patients group, and 29.5 in control group. 2. The amount of mandibular torque movement was not differed tin early protrusive and early left excursion between patients group and control group, but in early right excursion, patients group showed more value than control group did. 3. The distance on sagittal plane in early eccentric movements were longer in patients group than those in control group, but the distance of maximal eccentric movements were not significantly differed between patients group and control group. 4. Items which showed significant correlation with PRI were progressive side-shift, and horizontal torque movement in early protrusion and right excursion. 5. The angle of protrusive path of affected side was greater than of non-affected side in unilaterally affected patients, but the protrusive angle of preferred chewing side was not differed from that of contralateral side in control group. 6. The amount of torque movement in early protrusion and right excursion were greater in patients with coincidence of affected side and preferred chewing side than in patients without coincidence.

• Journal of the Korea Convergence Society
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• v.12 no.8
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• pp.335-343
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• 2021

The purpose of this study was determine the effect of sugar addition or gum chewing on the nausea, disgust, bowel preparation scale of through the subject taking the Coolprep as bowel preparation for colonoscopy. A randomized controledl trial design was used. There were 120 participants in the study, aged 20-65. The data were analyzed using one-way ANOVA and X² test using SPSS/WIN 25.0. There was no significant difference in nausea, disgust and bowel preparation scale among sugar additions, chewing gum and standard method groups. This study result therefore, convergent efforts are needed to reduce the difficulty of taking. The subjects who participated in the experiment did not have any special side effects such as hyperglycemia, so it is considered to be partially applicable to individual preferences.

• Journal of Oral Medicine and Pain
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• v.43 no.4
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• pp.147-151
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• 2018

Disuse atrophy involves gradual muscle weakening due to inadequate usage and can cause temporomandibular disorder (TMD). A 45-year old man with TMD symptoms on the left side, who had disuse atrophy of the masticatory muscles on the right side following surgical removal of a trigeminal schwannoma on the right side, first visited the Department of Orofacial Pain and Oral Medicine at Kyung Hee University Dental Hospital with left jaw pain and difficulty in opening mouth and chewing. He had been experiencing difficulties in cognitive function, decrease in visual acuity, impaired speech, and writing deficits after brain surgery. Furthermore, he complained of abnormal occlusion on the right side, which interfered with his ability to chew comfortably and open his mouth effectively. Herein, we describe a contralateral TMD case due to ipsilateral disuse atrophy after brain surgery for a trigeminal schwannoma and our successful treatment with medication, physical therapy, and stabilization splint.

• The Journal of Advanced Prosthodontics
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• v.3 no.1
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• pp.1-9
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• 2011

PURPOSE. This study investigated the strain of implants using a chewing simulator with strain gauges in mandibular implant-supported fixed prostheses under various dynamic loads. MATERIALS AND METHODS. Three implant-supported 5-unit fixed prostheses were fabricated with three different occlusion types (Group I: Canine protected occlusion, Group II: Unilaterally balanced occlusion, Group III: Bilaterally balanced occlusion). Two strain gauges were attached to each implant abutment. The programmed dynamic loads (0 - 300 N) were applied using a chewing simulator (MTS 858 Mini Bionix II systems, MTS systems corp., Minn, USA) and the strains were monitored. The statistical analyses were performed using the paired t-test and the ANOVA. RESULTS. The mean strain values (MSV) for the working sides were 151.83 ${\mu}{\varepsilon}$, 176.23 ${\mu}{\varepsilon}$, and 131.07 ${\mu}{\varepsilon}$ for Group I, Group II, and Group III, respectively. There was a significant difference between Group II and Group III (P < .05). Also, the MSV for non-working side were 58.29 ${\mu}{\varepsilon}$, 72.64 ${\mu}{\varepsilon}$, and 98.93 ${\mu}{\varepsilon}$ for Group I, Group II, and Group III, respectively. One was significantly different from the others with a 95% confidence interval (P < .05). CONCLUSION. The MSV for the working side of Groups I and II were significantly different from that for the non-working side (Group I: t = 7.58, Group II: t = 6.25). The MSV for the working side of Group II showed significantly larger than that of Group III (P < .01). Lastly, the MSV for the non-working side of Group III showed significantly larger than those of Group I or Group II (P < .01).