• The Journal of the Korean dental association
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• v.51 no.5
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• pp.255-264
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• 2013

Many concept of occlusion have been introduced in the past, but there isn't any generally accepted unified theory since a single occlusion theory cannot represent the natural perfection, especially considering the difference in clinical experience, the dynamic occlusion, and individual diversity in mastication pattern. NAT(Naturgemasse Aufwachstechnik)/NFR((Natur Funktionsgerechte Rekonstruktion) occlusion is not just a theory on occlusion, but a clinical occlusion that can be practically applied to clinical practice by providing dynamic occlusion adjusted to the individual mastication pattern and biomechanics. This report aims to provide a guide to a clinically biomechanical occlusion through the teamwork of both the dentist and the lab technician by introducing the NAT occlusion through following: reviewing the concept of occlusion in terms of morphology, its correlation with NAT/NFR occlusion, reviewing the limitation of conventional occlusion theories, and introducing the clinical application of NAT/NFR.

• The Journal of the Korean dental association
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• v.55 no.1
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• pp.82-89
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• 2017

Proponents of bilaterally balanced occlusion believe that this occlusal concept is important for denture retention and stability. However, the critical appraisal of the literature reveals no scientific evidence to support the bilaterally balanced occlusion as the ideal occlusal concept for conventional complete dentures. Current evidence suggests that the occlusal concept has little influence on clinical outcomes or patient satisfaction. Additional randomized controlled clinical trials should be developed taking into account the influence of mucosal resiliency, alveolar ridge anatomy, and parafunctional activities on occlusal concept choice. In this paper, various types of complete denture occlusion (bilaterally balanced occlusion, lingualized occlusion, canine-guided occlusion) will be reviewed and compared.

• Journal of the Ergonomics Society of Korea
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• v.30 no.5
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• pp.589-595
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• 2011

Objective: This study compares two visual occlusion methods for the evaluation of in-vehicle interfaces. Background: Visual occlusion is a visual demand measuring technique which uses periodic vision/occlusion cycle to simulate a driving(or mobile) environment. It has been widely used for the evaluation of in-vehicle interfaces. There are two major implementation methods for this technique: (1) occlusion using PLATO(portable liquid crystal apparatus for tachistoscopic occlusion) goggles; (2) occlusion using a software application on a touchscreen device. Method: An experiment was conducted to examine the visual demand of an in-vehicle interface prototype using the goggle-based and the touchscreen-based occlusion methods. Address input and radio tuning tasks were evaluated in the experiment. Results: The results showed that, for the radio tuning task, there were no significant differences in total shutter open time and resumability ratio between the two occlusionconditions. However, it took longer for the participants to input addresses with the touchscreen-based occlusion. Conclusion & Application: The results suggest that touchscreen-based method could be used as an alternative to traditional, gogglebased visual occlusion especially in less demanding visual tasks such as radio tuning.

• The Journal of the Korean dental association
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• v.53 no.6
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• pp.418-426
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• 2015

The appropriate occlusion is one of the most important factors for the long-term success of implant and its restorations. The purpose of this review is to investigate and define occlusal considerations to reduce failure of implant prostheses. The physiological movement of implants is markedly lower than that of natural teeth and they also lack in occlusal sensitivity. Proper occlusal pattern may be assigned to compensate for the biological disadvantages and occlusal contacts must be formed where the cantilever effect is minimized. Moreover, the long-term success of implants after osseointegration can be assured by reducing early occlusal loading to avoid implant overloading and selecting appropriate occlusion material. Occlusal overload was brought by the number and location of occlusal contacts, which are under the clinician's control. The concept of implant occlusion is based on the concepts derived from traditional prosthetics. Moreover, there are few evidence on the concept or design of implant occlusion. Several occlusal design was recommended for implant prosthesis. Mutually protected occlusion, group function occlusion and bilateral balance occlusion was recommended for the specific types of implant restorations. This article reviews proper design of occlusion for implant restoration and offers occlusion strategy clinically.

• The Journal of Korean Academy of Prosthodontics
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• v.31 no.1
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• pp.63-76
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• 1993

The purpose of this study was to investigate the disclusion time and occlusal pattern during lateral movement in normal group and temporomandibular dysfunction (TMD) group. Twenty dental college students of Chosun University without the abnormal occlusion and temporomandibular dysfunction were selected as a normal group, and twenty slight temporomandibular dysfunction (TMD) group and the ten moderate temporomandibular dysfunction (TMD) group classified according to Helkimo's dysfunction index were selected. Occlusal pattern was classified as canine guided occlusion, group functioned occlusion and the other group during lateral movement and disclusion time in lateral movement was measured using T-Scan system. The result were as follows: 1. The disclusion time according to each group were $1.24{\pm}0.58$ sec in normal $1.60{\pm}0.79$ sec in slight TMD group and $2.29{\pm}0.80$ sec in moderate TMD group. There was statistically significant between normal group and moderate TMD group(P<0.01), slight TMD group and moderate TMD group(P<0.05). 2. The distribution of occlusal pattern in normal group was 62.5% (25 side) in canine guided occlusion, 27.5% (15 side) in group functioned occlusion. 3. The distribution of occlusal pattern in slight TMD group was 45% (18side) in canine guided occlusion, 35% (14 side) in group functioned occlusion and 20% (8side) in others and that in moderate TMD group was 15% (3 side) in canine guided occlusion, 35% (7 side) in group funcconed occlusion and 50% (10 side) in other 4. The disclusion time in normal group was $1.05{\pm}0.59$ sec at canine guided occlusion and $1.53{\pm}0.72$ sec at group functioned occlusion. 5. The disclusion time in slight TMD group was $1.23{\pm}0.75$ sec in canine guided occlusion, $1.50{\pm}0.88$ sec in group functioned occlusion, and $2.61{\pm}0.57$ sec, in the other. There was staistically significant between canine guided occlusion and other(P<0.001)and group functioned occlusion and the other (P<0.05). 6. The disclusion time in moderate TMD group was $1.28{\pm}0.84$ sec in canine guided occlusion, $1.75{\pm}0.58$ sec in group functioned occlusion, and $2.98{\pm}0.08$ sec in the other(P<0.01).

• The Journal of the Korea Contents Association
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• v.19 no.7
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• pp.186-191
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• 2019

Introduction: In aged people, stroke incidence is increased. But standardized experimental animal protocol study for the research of stroke therapy is rare. There is little report on the success rate of cerebral artery occlusion model using standardized Nylon thread length of precise thread end-size controlled. Method: In this study, the operator intended the occlusion of middle cerebral artery (MCA) using $0.18{\pm}0.02mm$ end 5-0 Nylon thread. Middle cerebral artery occlusion was induced for 60min under isoflurane anesthesia. After 60min, the operator removed the Nylon thread and reperfusion was induced for 23hrs. The mice was killed 23hrs after reperfusion and infarction area of brain was confirmed by 1.5% TTC (2,3,5-tryphenyl tetrazolium chloride) staining. Results: According to end size and insert length of Nylon thread, Middle cerebral artery occlusion (n=50), internal carotid artery occlusion (n= 14), distal middle cerebral artery occlusion (n= 36), anterior cerebral artery (n= 1) were induced. And no infarction (n= 50) was observed. Conclusion: According to weight of mice, the operator induced reversible cerebral artery occlusion model by different insert length (30.0~36.9g : 9.0mm, 37.0~40.0g : 9.5mm) of Nylon thread. Success of cerebral artery occlusion model was confirmed by checking infarction area using TTC staining. The success rate (66.9%, 101/151) of reversible cerebral artery occlusion model in the mouse and the operational conditions are shown.

• The Journal of Advanced Prosthodontics
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• v.9 no.1
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• pp.45-51
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• 2017

PURPOSE. This study aims to investigate the effects of four different lateral occlusion schemes and different excursions on peri-implant strains of a maxillary canine implant. MATERIALS AND METHODS. Four metal crowns with different occlusion schemes were attached to an implant in the maxillary canine region of a resin model. The included schemes were canine-guided (CG) occlusion, group function (GF) occlusion, long centric (LC) occlusion, and implant-protected (IP) occlusion. Each crown was loaded in three sites that correspond to maximal intercuspation (MI), 1 mm excursion, and 2 mm excursion. A load of 140 N was applied on each site and was repeated 10 times. The peri-implant strain was recorded by a rosette strain gauge that was attached on the resin model buccal to the implant. For each loading condition, the maximum shear strain value was calculated. RESULTS. The different schemes and excursive positions had impact on the peri-implant strains. At MI and 1 mm positions, the GF had the least strains, followed by IP, CG, and LC. At 2 mm, the least strains were associated with GF, followed by CG, LC, and IP. However, regardless of the occlusion scheme, as the excursion increases, a linear increase of peri-implant strains was detected. CONCLUSION. The peri-implant strain is susceptible to occlusal factors. The eccentric location appears to be more influential on peri-implant strains than the occlusion scheme. Therefore, adopting an occlusion scheme that can reduce the occurrence of occlusal contacts laterally may be beneficial in reducing peri-implant strains.

• Journal of Korean Neurosurgical Society
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• v.37 no.1
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• pp.54-58
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• 2005

Objective: The purpose of this study is to determine the time evolution and distribution of cerebral apoptosis using the middle cerebral artery occlusion model in rats. Methods: A total of twenty four male rats - with 2, 3, 4, 6, 8, 12, 24 and 48 hours of middle cerebral artery occlusion respectively - were studied. The terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick-end labeling(TUNEL) method was used for the observation of the apoptotic cells. The apoptotic ratio was calculated and the distribution of apoptosis was inspected in the pyriform cortex, basal ganglia and middle cerebral artery territory cortex. The rats were divided into three groups(Group I : $2{\sim}4$ hours of occlusion, Group II : $6{\sim}$12 hours of occlusion, Group III : $24{\sim}48$ hours of occlusion). Results: In this study, the proportion of apoptosis increased with the duration of middle cerebral artery occlusion and reached a maximum after about 12 hours of middle cerebral artery occlusion. The mean values of the apoptotic ratio were $30.7{\pm}11.3%$ in group I, $60.8{\pm}2.6%$ in group II and $48.7{\pm}0.7%$ in group III. The distribution of apoptosis differed in the pyriform cortex, basal ganglia and middle cerebral artery territory cortex according to the duration of time of the middle cerebral artery occlusion. Conclusion: In the middle cerebral artery occlusion model of the rats, apoptosis is found to increase according to the occlusion time, reaching a peak after 6 hours, and the distribution of apoptosis changed from the pyriform cortex to the basal ganglia and middle cerebral artery territory cortex.

• The Korean Journal of Physiology
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• v.19 no.2
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• pp.173-187
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• 1985

Renal compensatory adaptation caused by ablation of a part of renal mass has long been known in the field of the compensatory renal hypertrophy or hyperplasia. Many reports were found on the chronic mechanisms on the compensatory renal hyperfunction after exclusion of the contralateral kidney. However the mechanism(s) of the acute compensatory hyperfunction after contralateral exclusion has not yet been clarified. In the present experiment, we have tried to prove the possibility of the involvement of the renin-angiotensin system and/or prostaglandin system in the control mechanism of the acute compensatory renal hyperfunction after contralateral kidney exclusion. There were found different responses of the renal hyperfunction by contralateral renal pedicle or ureteral occlusion. Contralateral renal pedicle or ureteral occlusion caused a sustained increases of the urinary volume, sodium and potassium excretion, while the magnitude of the changes was different quantitatively by the maneuvers. Blood collection affected on the acute compensatory renal responses after ureteral as well as renal pedicle occlusion. Plasma prostaglandin $E_2$ level was not changed by the contralateral renal pedicle or ureteral occlusion. Urinary excretion of Prostaglandin $E_2$, the indices of renal prostaglandin biosynthesis, was not changed by the contralateral renal pedicle occlusion, but increased without significance by the contralateral ureteral occlusion. Acute renal compensatory responses after contralateral renal pedicle occlusion were blocked by the pretreatment of indomethacin. Plasma renin activity increased after contralateral ureteral occlusion, but the pattern of the increases was the same as in the time-control group. Plasma renin activity after contralateral renal pedicle occlusion did not change by the time sequence. SQ 20,881, an angiotensin I converting enzyme inhibitor, blunted the contralateral renal responses after the renal pedicle occlusion. Bilateral renal denervation abolished the contralateral renal responses after the renal pedicle occlusion. The above data suggest that there is no direct evidence to support the involvement of the renin-angiotensin system and/or prostaglandin system for the acute compensatory renal hyperfunction after contralateral kidney exclusion, and that the functional changes of the intact kidney may be caused by a humoral substances, or other mechanisms by afferent renal nerve activity originating from the treated kidney.

• Journal of Technologic Dentistry
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• v.11 no.1
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• pp.115-120
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• 1989

Many attempts for the compfrt, esthetics and improvement of Masticatory function of the patients with removable prosthesis have been made for several decades. The search for the ideal denture occlusion has been going on in an effort to find the tooth form which provides maximum denture stability and masticatory efficiency without damaging the health of the underlying bone. For the purpose, the basic concept of lingualized occlusion were suggested by payne(1941) and pound(1973) discussed a similar occlusal concept and used term " lingualized occlusion." The purpose of this literature study is to clarify and amplify a method to achieve bilateral balanced occlusion with the occlusal arrangement termed " lingualized occlusion." Lingualized occlusion can be achieved by use of anatomic teeth for the mandibular denture. Lingualized occlusion can be used in most denture combination. It is particulary helpful when the patient places high priority on esthetics but a nonanatomic occlusal scheme is indicated by oral conditions such a severe alveolar resorption, a class II jaw relationship or displaceable supporting tissue. Advantages of lingualized occlusion are summarized as follows : 1) Most of the advantages attributed to both the anatomic and nonanatomic forms are retained. 2) Cusp form is more natural in appearance compare to nonanatomic tooth form. 3) Good pnetration of the food bolus is possible. 4) Bilateral mechanical balanced occlusion is readily obtained for a region around arotric relation. 5) Bertical forces are centralized on the mandibular teeth. Lingualized occlusion provides a useful combination of several occlusal concept. Many. advantages of anatomic and nonanatomic occlusions are accomplished but the lingualized occlusal concept is not is not a panacea, and all other procedures still must be carefully excuted.