• Journal of Oral Medicine and Pain
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• v.48 no.4
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• pp.152-158
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• 2023

Purpose: This pilot study aimed to evaluate changes in joint space (JS) using cone-beam computed tomography (CBCT) images of patients diagnosed with temporomandibular joint (TMJ) osteoarthritis (OA) and to determine the association between occlusal changes and JS. Methods: CBCT images were used to measure the anterior, superior, and posterior JSs of the sagittal plane. The differences in JS values over time and between groups were compared. The percentage change in the anteroposterior position of the mandibular condyle between groups was also analyzed. Results: Thirty-four subjects (mean age=43.91±20.13), comprising eight males (23.5%) and 26 females (76.5%), were divided into 18 patients with no change in occlusion (NCO) and 16 patients with a change in occlusion (CO) during TMJ OA. The JS measurements of the study subjects showed a decrease in anterior joint space (AJS) values over time. There was no difference in JS measurements between the groups at T1 and T2. AJS values measured at T1 were lower in the CO group than in the NCO group, but the difference was not statistically significant. In both groups, a posterior position of the mandibular condyle was initially observed with high frequency. However, there is a statistically significant difference in CBCT images taken after occlusal changes, with an increased frequency of condyles observed in the anterior or central positions. Conclusions: In conclusion, AJS decreased over time in TMJ OA, and the mandibular condyle became more anteriorly positioned with occlusal changes. Therefore, clinicians should diligently monitor mandibular condyle morphology and JS using CBCT, along with the patient's clinical symptoms, to treat and control TMJ OA effectively.

• The korean journal of orthodontics
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• v.13 no.1
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• pp.73-82
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• 1983

The author studied on the dental arch widths and lengths and height of palates at 3 groups of dentition: mixed dentition, early permanent dentition, young adult, having normal occlusion and dentition. The models of the 336 maxillary and mandibular case, made from alginate-base hydrocolloid impressions were measured and analyzed statistically. The result as follows; 1. The upper intercanine width increased between the mixed dentition group and early permanent dentition group but there was no change in the young adult group in both sexes. The lower intercanine width increased between the mixed dentition group and early permanent dention group in the male. 2. The upper and lower 1st bimolar width increased slightly with age in the male but there was no change in the female. 3, The sex difference found in this study was one of absolute size, the female being slightly smaller than the male in the early permanent dentition group and young adult. 4. The arch length had no notable sexual differences and decreased between the mixed dentition group and early permanent dentition group. There was no change in the arch length in the young adult. 5. The height of palate increased gradually with age.

• Journal of Dental Rehabilitation and Applied Science
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• v.26 no.1
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• pp.1-12
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• 2010

The purpose of this study was to compare the strain on the alveolar ridge in the centric, eccentric and protrusive position according to the occlusal scheme (bilateral balanced occlusion with 33 degree anatomical teeth, group B; monoplane occlusion with non-anatomical teeth, group M; lingualized occlusion with 33 degree anatomical teeth and non-anatomical teeth, group L; of complete dentures. Experimental dentures were set bilateral balanced occlusion, lingualized occlusion and monoplane occlusion. They are analysed through T-Scan II(Tekscan, Boston, U.S.A) and 1.5mm thick layer was removed from the denture-supporting surface of resin model and then replaced with silicone to simulate resilient edentulous ridge mucosa. A $4{\times}6$ linear strain gauge is attached to the $1^{st}$ premolar and $1^{st}$ molar area. The strain values are recorded according to the occlusal scheme in the centric, eccentric and protrusive position after uniformly applying 50 N and 150 N force through a Universal Testing Machine(instron$^{(R)}$ 5567, Bluehill 2.0 software ,U.S.A.) with the models mounted in the articulator. When performing centric and protrusive occlusion, the three groups of occlusal scheme were compared in the anterior region and in the posterior region. The strains of each group were also compared in the working side and in the non-working side during eccentric excursion. It was observed that the strain in the bilateral balanced occlusion showed a higher value than the lingualized occlusion and monoplane occlusion in every position except the non-working side. However, during the eccentric movement the strain value in the non-working side showed the lowest value in the bilaterally balanced occlusion. The strain change amount from the working side or centric occlusion to non-working side and also the strain variation rate within the non-working side showed the highest value in bilateral balanced occlusion.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.17 no.1
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• pp.151-162
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• 1987

The author obtained the computed tomograms around the condylar head from 10 normal subjects and 5 patients having clicking condylar head from 10 normal subjects and 5 patients having clicking sound or limitation of mouth opening by using a Hitachi-W 500. And then. the author had the axial analysis of condyle position and sagittal analysis of that after sagittal reformation on centric occlusion and 18㎜ interincisal opening. Transcranial view and submentovertex view were taken and compared with computed tomographic view. The obtained results were as follows: 1. Median angle of long axis of condylar head was 17 degrees on centric occlusion and the angles of long axis of both condylar heads were reduced symmetrically on 18㎜ interincisal opening in normal group. however. in the patient group, the affected side of condyle heads showed greater change in the angle on 18㎜ interincisal opening. 2. In the patient group, the condyle head of affected side was located superiorly to that of normal side on centric occlusion and the discrepancy of condular positional height was increased after 18㎜ interincisal opening. 3. The distances from medial pole of condylar head to triangular fossa of temporal bone were same on both right and left side in normal group, however, in the patient group, the distance of affected side was wider than that of opposite side on centric occusion and became narrower than the opposite side on 18㎜ interincisal opening. 4. The distances of posterior joint space were same on both right and left side. The distance t lateral pole 1/3 of condyle head was similar to that on transcranial view on centric occlusion in normal group. 5. The distances of posterior joint space were narrower in patient group than in normal group. 6. Conclusively, the affected condylar head of patient showed postero-latero-superior displacement on centric occlusion and larger range of rotational movement on 18㎜ interincisal opening.

• The Journal of Korean Academy of Prosthodontics
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• v.55 no.4
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• pp.419-426
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• 2017

In implant restorations, it is difficult for the patient to percept any symptoms. In addition, they are absent of shock absorbers, which can lead to mechanical failure if stress distribution is not considered. Since maxillary anterior multiple-implant restorations play a significant role in guiding the functional movement of the mandible by distributing lateral force, it is crucial to form appropriate occlusion. The use of the T-scan system is more advantageous in assessing 'dynamic occlusion', such as the change of occlusion over time, the amount of tooth contact during functional movement, and assessing the occlusion in the less-visible posterior teeth. The case is reported as it has satisfactory results in harmonious anterior guidance of a maxillary anterior multiple-implant restoration using T-scan analysis.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.43 no.1
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• pp.37-41
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• 2017

Objectives: The aim of this study was to evaluate the implication of third molars in postoperative complications of mandibular angle fracture with open reduction and internal fixation (ORIF). Materials and Methods: Data were collected on patients who presented with mandibular angle fracture at our Department of Oral and Maxillofacial Surgery between January 2011 and December 2015. Of the 63 total patients who underwent ORIF and perioperative intermaxillary fixation (IMF) with an arch bar, 49 patients were identified as having third molars in the fracture line and were followed up with until plate removal. The complications of postoperative infection, postoperative nerve injury, bone healing, and changes in occlusion and temporomandibular joint were evaluated and analyzed using statistical methods. Results: In total, 49 patients had third molars in the fracture line and underwent ORIF surgery and perioperative IMF with an arch bar. The third molar in the fracture line was retained during ORIF in 39 patients. Several patients complained of nerve injury, temporomandibular disorder (TMD), change of occlusion, and postoperative infection around the retained third molar. The third molars were removed during ORIF surgery in 10 patients. Some of these patients complained of nerve injury, but no other complications, such as TMD, change in occlusion, or postoperative infection, were observed. There was no delayed union or nonunion in either of the groups. No statistically significant difference was found between the non-extraction group and the retained teeth group regarding complications after ORIF. Conclusion: If the third molar is partially impacted or completely nonfunctional, likely to be involved in pathologic conditions later in life, or possible to remove with the plate simultaneously, extraction of the third molar in the fracture line should be considered during ORIF surgery of the mandible angle fracture.

• The Journal of Korean Medicine
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• v.22 no.4
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• pp.142-150
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• 2001

Objectives : The purpose of this investigation is to evaluate and compare the effects of Sunghyangjunggi-san (SH) and Gwackhyangjunggi-san (GH) extracts on reperfusion following the MCA occlusion in rats. Methods : To evaluate the effect of Sunghyangjunggi-san (SH) and Gwackhyangjunggi-san (GH) extracts on reperfusion following the MCA occlusion, the volume of cerebral infarction and edema were measured and the change of the CA1 pyramidal neurons in the hippocampus were investigated by light microscopy. Results : 1. The infarction volume of the control group was 23.6%, that of the GH group was 23.7%, and that of the SH group was 18.5%. 2. The brain edema volume of the control group increased by 16% compared with that of the normal group, that of the GH group increased by 14%, and that of the SH group increased by 9%. 3. The number of surviving pyramidal neurons in the CAI area of the hippocampus was investigated under light microscopy. In the control group, few surviving pyramidal neurons excisted (mean 6.4) and similarly in the GH group (mean 8.5), but in the SH group, the number of surviving pyramidal neurons was significantly higher, to the mean 18.4. Conclusions : According to the above results, in regard to the damage of neurons following cerebral ischemia, the GH group has little effect of the protection of neurons compared to the control group, but the SH group has a remarkable effect.

• Journal of Haehwa Medicine
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• v.8 no.1
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• pp.425-449
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• 1999

For the evaluation of the effect on SWS, experiments were made on hyperlipidemia induced by hypercholesterol diet, inhibitory reaction to human platelet aggregation, Pulmonary thrombosis induced by collagen and epinephrine, global cerebral ischemia induced by KCN, brain ischemia induced by MCA occlusion, cytotoxicity of PC12 cells induced by amyloid ${\beta}$ protein(25-35), and NO production in RAW cells stimulated by lipopolysaccharide. The results were obtained as follows : 1. In the experiment on hyperlipidemia, the level of serum total cholesterol, phospholipid, and LDL-cholesterol were significantly decreased while the level of triglyceride, VLDL-cholesterol, and HDL-cholesterol had no significant change. 2. In the experiment on inhibitory reaction to platelet aggregation, SWS inhibited platelet aggregation induced by ADP(36.05%), by collagen(20.4%), and by thrombin(0.6%). 3. In the experiment on pulmonary thrombosis induced by collagen and epinephrine, the protective effect was found(37%). 4. In the experiment on global cerebral ischemia, coma duration induced by KCN changed insignificantly. 5. In the experiment on MCA occlusion, the change of neurologic grades on hind limb was significant only after the operation. Besides brain ischemic area and edema ratio were significantly decreased. 6. In the experiment on cytotoxicity of PC 12 cells induced by amyloid ${\beta}$ protein, the significant protective effect was found as concentration increases. 7. In the experiment on NO production in RAW cells stimulated by lipopolysaccharide, NO was significantly decreased. According to the results, it is expected that SWS might be effective on hyperlipidemia and brain damage.

• Archives of Plastic Surgery
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• v.37 no.5
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• pp.547-554
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• 2010

Purpose: The purpose of this study is to delineate the optimal time of venous revascularization for preventing the flap necrosis due to venous occlusion, and to clarify the usefulness of tissue oxygen pressure ($TcpO_2$) in the determination of the point of time for venous revascularization. Methods: Thirty-six, $3{\times}3\;cm$ sized epigastric island flap was elevated in left abdomen of male Sprague-Dawley rat weighing 250 gram. Flaps were randomly assigned to six groups of six flaps according to the duration of venous occlusion with microvascular clamp; 10 minutes in the group I as the control, 60 minutes in the group II, 2 hours in the group III, 3 hours in the group IV, 4 hours in the group V, and 6 hours in the group VI, respectively. Just before removal of clamp after flap was reposed in situ, the ratio of $TcpO_2$ (tissue oxygen pressure) of the island flap to that of right abdomen was calculated in each group, and tissue specimen was harvested from the distal area of the flap for histological evaluation of vascular change. Five days later, survival area of the flap was estimated, and evaluated the correlation between the tissue oxygen pressure and the rate of flap survival. Results: The $TcpO_2$ and the survival rate of flap were decreased proportionally with the duration of venous occlusion. The ratio of the $TcpO_2$ of the flap is decreased abruptly to below sixty percentile compared to the $TcpO_2$ of normal tissue, and the survived area of the flap is decreased to nine-tenth of the designed size after three hours of total venous occlusion. Histologically, the number of congested vessels was increased according to venous occluded time, and proportionally increased after 3-hours of occlusion significantly. Conclusion: There is a close correlation between the $TcpO_2$ and the survival rate of flaps according to the duration of venous occlusion. Therefore, the $TcpO_2$ represents the hemodynamic changes within the flap, and thought to be an alternative effective tool in the flap monitoring for venous revascularization.

• Proceedings of the KIEE Conference
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• 2005.07d
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• pp.2796-2798
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• 2005

This Paper presents a method that a mobile robot can track persons in complex environment using particle filters. The topic of person following using mobile robot is researched in many different areas. The main problems of following a person are real time constraint, motion change of person during the tracking and occlusion with other objects. We present appearance adaptive models in a particle filter to realize robust visual tracking algorithm. Adaptive appearance model can handle occlusion with other people while target is moving.