• Journal of Oral Medicine and Pain
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• v.17 no.2
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• pp.37-49
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• 1992

80 patients who presented at Wonkwang University Dental Hospital with craniomandibular disorders were collected for this study. To observe the occlusal contact pattern such as contact numbers, contact force and presence or absence of anterior occlusal contact, the author used T-Scan system (Tekscan, Inc, U.S.A.) with are computerized occlusal analysing system. And to study the correlation between craniofacial profile and occlusal contact pattern, cephalogram were also taken, The cephalometric items related to growth pattern, jaw bone relation and denture pattern were measured and analysed according to routine method by computerized program. The obtained data were statistically processed with SPSS/PC+ package about anterior contact pattern and its craniofacial relationship. The obtained results were as follows : 1. In terms of growth pattern, patients without anterior tooth contacts showed a tendency to downward growth of craniofacial profile. The value in this subjects were significantly different from the value of patients with anterior tooth contacts in items of low gonial angle, Jarabak ratio, SN to GoMe angle, FMA, occlusal plane to mandibular plane angle and ramus height. 2. In terms of jaw bone relationship, patients without anterior tooth contacts showed a tendency to backward growth of craniofacial profile. The value of this patients were significantly different from the value of patients with anterior tooth contacts in items of SNB, ANB, mandibular plane to anterior cranial base ratio, SNPo, NAPo and APDI items. 3. But in denture pattern, no statistically significant difference by the presence or absence of anterior tooth contacts were showed between this patients groups. 4. From this study, it could be proposed that anterior open bite in the patients with craniomandibular disorders would be originated from not dental discrepancy but skeletal discrepancy.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.1391-1394
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• 2007

In order for Hypoid gear development. Gears are required to sustain heavy loads or on applications where the gear box is made or a material with a different coefficient of thermal expansion form that or the gears and shafts, it is desirable to make a deflection and contact check under load. The deflection test is performed in the actual gear mounting using completely processed gear. This test should cover the full operating range of gear loads from no load to peak load. Under peak load the contact pattern should extend to the tooth boundaries without showing a concentration of the contact pattern at any point on the tooth surface.

• Journal of Power System Engineering
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• v.13 no.6
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• pp.102-109
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• 2009

A retarder, as a supplementary brake system that is not friction-based, is frequently used in heavy-duty vehicles generally to slow the vehicles down on inclines. The electric retarder mainly used in a heavy-duty bus is generally placed between the transmission and the axle. The rotor inside the retarder system is attached to the axle. The operation of the retarder within a driven vehicle generates reverse torque due to coast driving force on hypoid gears in the differential gear system. By the reverse torque, scoring or scuffing on the hypoid gear teeth may directly occur. The scoring may be generated due to excessive contact stresses on the tooth surface. In this study, tooth contact stresses and contact patterns were analysed in order to investigate on the tooth scoring phenomenon using a finite element analysis program T900 in which the Hertzian contact stress formula was taken. Backlash, wear and surface finish were considered in the finite element simulation on the scoring.

• The Journal of the Korean dental association
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• v.22 no.10 s.185
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• pp.869-877
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• 1984

An objective examination of 123 subjects aged from 19 to 23 was made from a clinical standpoints to determine the natural occurrence in anterior tooth contact in centric occlusion, and tooth contact in protrusive occlusion, left and right lateral excursions, and temporomandibular dysfunction. 1. In centric occlusion, maxillary 6 anterior contact type was frequently observe (30.08%) compared with other types of contact (incisor contact: 19.47%, no contact: 17.70%, canine and incisor contact: 15.04%, canines contact: 12.39%, unilateral canine contact: 5.31%) (P<0.01) 2. In protrusive position (edge to edge bite), maxillary central incisors contact was predominant (86.7%). (P<0.01) 3. In lateral excursion, there was not any significant difference between canine guided occlusion (47.79%) and group function occlusion (total 51.32%, AG:9.29%, PG:13.27%, G:28.76%). 4. Temporomandibular joint dysfunction was observed in 12.4% of 123 subjects.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.4
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• pp.70-75
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• 2011

Nowadays, modern gearboxes are characterized by high torque load demands, low running noise and compact design. Also durability of gearbox is specially a major issue for the industry. For the gearbox which used in wind turbine, gear transmission error(T.E.) is the excitation that leads the tonal noise known as gear whine, and radiated gear whine is also the dominant source of noise in the whole gearbox. In this paper, tooth modification for the high speed stage is used to compensate for the deformation of the teeth due to load and to ensure a proper meshing to achieve an optimized tooth contact pattern. The gearbox is firstly modeled in Romax software, and then the various combination analysis of the tooth modification is presented by using Windows LDP software, and the prediction of transmission error under the loaded torque for the helical gear pair is investigated, the transmission error, contact stress, root stress and load distribution are also calculated and compared before and after tooth modification under one torque condition. The simulation result shows that the transmission error and stress under the loads can be minimized by the appropriate tooth modification.

• Journal of Oral Medicine and Pain
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• v.23 no.2
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• pp.143-155
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• 1998

This study was performed to investigate the factor that might affect mandibualr body rotation. For the study, 115 patients with temporomandibular disorders and 35 dental students without angy signs and symptoms of temporomandibular disorders were randomly selected as the patient group and the contreol group, respectively. Preferred chewing side, Angle' classification, lateral guidance pattern, and affected side were clinically recorded, and the amount of Mandibular body rotational torque movement was measured in wide opening and closure, in right and left excursion with vertical and lateral distance in frontal plane, right and left rotational angel in horizontal and in frontal plane. Masticatory muscle activity of anteriorocclusal contact pattern on maximal hard biting were also observed synchronously with BioEMG and T-Scan , respectively. The observed items were muscle activity of anterior temporalis and superficial masseter, and tooth contact status related to contact number, force, duration, and occlusal unbalance between right and left arch. The data collected were analyzed by SAS statistical program. The results of this study were as follows : 1. Mean value of vertical distance in frontal plane in wide opening and closure was more in control subjects than in patients, but there was no difference for rotational angle. In right excursion, rotational angles were greater in patient group than in control group. 2. Comparison among the subjects by preferred chewing side did not reveal any significant difference, but comparison among patients by affected side showed more rotational amount in bilaterally affected patients than in unilaterally affected patients. 3. Comparison among the subjects by Angle's classification or lateral guidance pattern revealed no difference. There was also no difference between preferred chewing side and contralateral side, and between affected side and contralateral side. 4. Positive correlation in madibular rotational torque movements were observed among vertical distance, total horizontal rotation angle, electromyographic activity of anterior temporalis, tooth contact number, and tooth contact force but total frontal rotation angle almost did not show any correlation with other variables except vertical distance.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.6
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• pp.92-99
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• 2021

The rotavator is attached to the three-point hitch at the rear of a tractor and uses the power take-off strength of the tractor to perform soil harrowing. During operation, the power transmitted to the gearbox of the rotavator varies with the soil characteristics and depth. These properties influence the reliability of the gearbox. In this study, actual load measurements and analyses were performed using a rotavator. In addition, the safety factor and fatigue life of the gearbox components were determined using the analysis results. Through analysis and tests, the contact pattern of the gear tooth surface was identified. The input power values of the gearbox were minimum and maximum at 54.5% and 84.5% of the tractor power, respectively. Based on the actual load analysis results, the strength and fatigue life of the gearbox components were satisfied. In addition, through the analysis and testing of the gear contact pattern, it was confirmed that a similar contact occurred. Through the analysis, the magnitude of the load acting on the tooth surface of the gear was confirmed.

• Journal of Oral Medicine and Pain
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• v.19 no.2
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• pp.153-168
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• 1994

The aim of the present study was to investigate a relation between occlusal wear area and occlusal contact patterns. For the purpose, occlusal wear area were measured in 58 dental students and in 129 patients with temporomandibular disorders(TMDs) from dental casts. Teeth used in this study were from canine to second molar on both sides in upper arch, totally ten. Occlusal wear area on casts was marked by pencil and photocopies, and then, the area was measured with planimeter. Occlusal relation was clinically examined with regard to Angle's classification, chewing side preference, lateral guidance pattern and bruxing and/or clenching habit. T-Scan, electronic occlusal contact analyzer, was used to record occlusal contact number, contact force, contact time and occlusal balance that is TLR(total left-right statistics) during tooth contact. All measurement were repeated 3 times and the average value was used for data processing. The obtained results were as follows : 1. Mean value of occlusal wear area did not differ significantly between dental students and patients. 2. There ws not significant difference in wear area between chewing side and non-chewing side in both groups. 3. Occlusal wear area was significantly increased with age in both groups. 4. Three subgroups divided by Angle's classification did not show any difference in occlusal wear area among them, but three subgroups divided by lateral guidance pattern showed slightly significant difference between canine guide subgroup and group function subgroup in patients. Occlusal wear ares\a in group function subgroup wear larger than canine guide subgroup. 5. Mean value of wear area in patients with bruxing and/or clenching habit did not differ from those in patients without such habit. 6. Correlationship among items related to occlusal contact pattern were highly consistent and significant in dental students and only one item significantly correlated with occlusal wear area was tooth contact time.

• The Journal of Korean Academy of Prosthodontics
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• v.28 no.2
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• pp.77-90
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• 1990

The purpose of this study was to compare the amount of the vertical pin opening of $33^{\circ}$ resin and $0^{\circ}$ resin teeth during processing and to determine whether the changes in tooth contacts by using articulation ribbon and T-Scan system follow any identifiable pattern, and to determine if there is any correlation between the changes in tooth contacts and the amount of the vertical pin opening after processing. Through statistical analyses on the data from this study, the following conclusions were obtained. 1. The amounts of the vertical pin opening were 0.78m, 0.87mm for $0^{\circ}$ teeth and $33^{\circ}$ teeth, respectively. But there was no significant difference between them. 2. The total number of contact points recorded by articulating ribbon after processing was decreased to 442.5% of that before processing. 3. The mean values for the number of contact points per tooth recorded by articulating ribbon after processing were 4.3 for the second molar, 3.8 for the first molar, 1.3 for the second premolar, 0.8 for the first premolar. The reduction of contact points per tooth became greater moving in an anterior direction. 4. The correlation between the reduction of contact points and the amount of the pin opening after processing was not significant. 5. The mean values for the numbers of contact points per tooth recorded by T-Scan system after processing were 2.2, 2.5, 1.0, and 0.5 at the second molar, the first molar, the second premolar, and the first premolar, respectively. 6. The correlation between the number of contact points by using articulating ribbon and TScan system after processing was not significant.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.11a
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• pp.91-98
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• 2008

Hypoid gears are widely used in rear drive and 4WD vehicle axles. Investigation of their sensitivity to deflections is one of the most important aspects of their design and optimization procedures. The deflection test is performed in the actual gear mounting using completely processed gear. This test should cover the fun operating range of gear loads from no load to peak load. Under peak load the contact pattern should extend to the tooth boundaries without showing a concentration of the contact pattern at any point on the tooth surface. Transmission error is tested on an axle assembly triaxial real car load condition.