• 대한소아치과학회지
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• 제32권1호
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• pp.89-100
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• 2005

형태학적으로 아주 유사한 상, 하악 제2유구치와 제1대구치의 교합면 형태를 분석하고자 정상교합의 유치열기 아동(Hellman dental age II A) 100명(남자 50명, 여자 50명)과 영구치열기의 성인(Hellman dental age IV A) 86명 (남자 43명, 여자 43명)을 대상으로 하였다. 상, 하악 제2유구치와 제 1대구치의 상, 하악 석고모형의 3차원 형상 data로부터 각 교두정간 거리, 교두정을 최소한의 오차로 지나는 평면과 교합면사이의 체적, 평면에서 교두정간 까지의 방향별 Section curve를 구하여 다음과 같은 결론을 얻었다. 1. 형성된 표준평면과 각 교두정과의 거리에 관한 오차는 하악 제2유구치에서 남자 0.05-0.09mm, 여자 0.04-0.09mm로서 제일 작았다. 2. 각 교두정간의 거리는 하악 제2유구치와 제 1대구치 에서 남자가 크게 나타났다. 특히 제2 유구치에서는 유의성이 존재하였다(p<0.05). 3. 남녀 모두에서 사주 교두거리를 제외하고, 상악 제2유구치는 원심 협측교두와 설측교두 사이가, 하악 제2유구치는 원심교두와 원심 설측교두 사이가, 상악 제1대구치는 근심 설측교두와 협측교두 사이가, 하악 제1대구치는 원심 설측교두와 근심 설측교두 사이의 거리가 가장 크게 측정되었다. 4. 제2유구치와 제1대구치에서 교합면 체적은 하악에서 크게 나타났고, 영구치가 1.40-1.75배 값을 보였으며(p<0.05), 남녀간에는 남자가 큰 값을 보이긴 하였지만 통계적인 유의성이 없었다. 5. 대부분의 경우 유치열에서 보다 영구치열에서 section curve가 넓고 깊었으며 교두사이의 사선거리를 제외하고 상악의 경우 근심 협측과 설측교두 사이에서 유치열과 영구치열 모두에서 가장 깊은 section curve를 이루었으며 하악에서는 영구치열은 원심 협측과 원심교두사이 유치열은 원심 설측과 원심교두 사이에서 가장 깊은 section curve를 이루었다.

• 대한치과보철학회지
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• 제33권1호
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• pp.75-84
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• 1995

This study was designed as a reference of vertical dimension in prosthetic treatment. The author analyzed six facial measurements, namely, (1) the height of lower face at maximum intercuspal position, (2) the height of lower face at resting position, (3) midface, (4) external ear and lateral wall of orbit, (5) interpupillary distance, (6) distance between pupil and mouth in the 100 Won-kwang Univ. Dental collage students(50 : male, 50 : female), who have normal occlusion, no posterior prosthesis, no experience of orthodontic treatment, and no deformity of facial soft tissue and no temporomandibular dysfunction. The results of this study were as follows : 1. The length of midface was shortest and the inter-pupillary distance was longest in both male and female. 2. The length difference with the length of midface and lower face at maximum intercuspal position was 5.64mm in male and 2.23mm in female, so the lower face was longer, 3. The facial measuring component, similar to lower face at maximum intercuspation, was the length of between medial wall of external ear and lateral wall of orbit. It's difference was 1.3mm in male, 1.77mm in female, and the lower face was shorter. 4. The difference of lower facial length in resting position and maximum intercuspation was 2.48mm in male, 2.24mm in female, the length of resting position was therefore longer. 5. The most clost correlation with the height of maximum intercuspal positioning lower face was resting lower face in both groups.

• Journal of Oral Medicine and Pain
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• 제20권1호
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• pp.195-204
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• 1995

The purpose of this study was to evaluate effect of head posture change on initial occlusal contacts through measuring the distances between initial occlusal contacts and maximum intercuspal position at different head posture. Two special devices were designed and constructed. Mandibular movement replicator was used to assess reliability of the K6 diagnostic system(MKG; Myo-tronic Inc, Seatle, USA) and head posture calibrator was used to maintain the constant head posture during experiment. We measured difference of distance between initial occlusal contact and maximum intercuspal position with MKG in upright, supine, 45 degrees extension, 30 degrees flexion, 30 degrees right and left bending postion of the head. The Frankfurt horizontal plane was used as a reference plane. 21 adults aged from 23 to 25 were selected, who have normal or class I molar relationship, and have no symptoms on TMJ and masticatory muscles, and have restorations less than 3 surfaces on each tooth, and have no other prosthetic restoration. The obtained results were as follows : The mean absolute distances between initial occlusal contact and maximum intercuspal postion were 0.39(0.18mm in the upright position, 0.65(0.37mm in the supine position, 0.59(0.33mm in the 45 degree extension, 0.70(0.53mm in the 30 degrees flexion, 1.12(1.10mm in the 30 degrees right bending and 1.94(0.67mm in the 30 degrees left bending of the head. The positions of the initial occlusal contacts have a tendency to locate anterior, left and inferior to maximal intercuspal position in upright position, posterior and inferior in supine position and 45 degrees extension, anterior and inferior in 30 degrees flexion, right and inferior in 30 degrees right bending, and left and inferior in 30 degrees left bending of the head. There were significant differences among the initial occlusal contacts in each head postures(P<0.0001). Therefore, we need to check initial occlusal contacts in the altered head posture during occlusal analysis and adjustment of occlusal appliance and dental occlusion for diagnosis and treatment of temporomandibular disorder.

• Journal of Oral Medicine and Pain
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• 제20권2호
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• pp.489-496
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• 1995

The purpose of this study was to evaluate an effect of change on head posture initial occlusal contacts with measuring the distances between initial occlusal contacts and maximum intercuspal position at different head posture in TMDs patient. For this study, 24 patients from age 13 to 36 were selected, they were examined health history taken, patients who have sign and symptoms of TMDs were examine before the study. For the normal group, 21 adults from age 23 to 25 were selected. They have normal or class I molar relationship, and have no other prosthetic restorations. Difference on distance between initial occlusal contact and maximum intercuspal position with mandibular kinesiograph$(MKG^R)$(K6 diagnostic system, Myo-tronic Inc, USA) in upright, supine, 45$^{\circ}$ extension, 30$^{\circ}$ flexion position of the head were measured. The Frankfort horizontal plane was used as a reference plane. The results were as follows : 1. There were significant differences between initial occlusal contacts of the normal and patient group on upright position and 30$^{\circ}$ flexion of the head(p<0.05, p<0.01) 2. The position of the initial occlusal contacts have a tendency to place anterior and inferior to maximal intercuspal position in upright position and 30( flexion of the head as well as posterior and inferior in supine position and 45$^{\circ}$ extension of the head in the normal and patient groups. 3. There were significant differences among the initial occlusal contacts between uptight and supine position; upright and 45$^{\circ}$ extension of the head(p<0.05); supine position and 30$^{\circ}$ flexion of the head, .and 30(flexion and 45$^{\circ}$ extension of the head in the patient group(p<0.01) The result have shown that after treatment on the supine position, it may be necessary to check occlusal contact on the upright position as well ass flexion of the head. It may need careful adjustment in occlusal condition on upright position of TMDs patient.

• 대한치과보존학회:학술대회논문집
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• 대한치과보존학회 2003년도 제120회 추계학술대회 제 5차 한ㆍ일 치과보존학회 공동학술대회
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• pp.563-563
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• 2003

The purpose of present study was to evaluate the polymerization shrinkage stress and cuspal deflection in maxillary premolars resulting from polymerization shrinkage of composites and compomers. 1)Measurements of polymerization shrinkage stress. For measurements of polymerization shrinkage stress, Stress measuring machine(R＆B, Daejon, Korea) was used. Composites and compomers which were used in this study were as follows：(omitted)

• 대한치과보철학회지
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• 제37권2호
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• pp.242-255
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• 1999

The purpose of this study was to estimate the morphology and the size of permanent mandibular molar in Korean Adult. The 100 dental college students with a normal dentition and without any dental prosthesis and severe caries were selected for this study The subjects were taken impression to make study model. On the study model, the 5 dentists measured those sizes and estimated morphological structures with a calipers, a Boley gauge and a protractor. The results were as follows; 1. The clinical crown height, width, thickness and the other anatomical structures had symmetrical relationship between the left and right mandibular molar. 2. In the clinical crown height aspect, the buccal crown heights always were higher than the lingual crown height. The heights of the each surface, the buccal or lingual surface, were gradually decreased from the 1st molar to the 2nd molar and the difference on the buccal surface was higher than that on the lingual surface. 3. In the clinical crown width aspect, the mesiodistal measurement of the mandibular 1st molar was higher than that of the mandibular 2st molar. 4. In the clinical crown thickness aspect, the mesial buccolingual measurement was highest on the mandibular 1st molar and the distal buccolingual distance was lowest on the mandibular 2nd molar. This distal thickness of the mandibular molar always was higher than that of the mesial half. 5. The well-developed mesiobuccal groove of the 1st molar was observed more often than that of the 2nd molar. The buccal pit was also observed more frequently at the 1st molar, but the frequency(35%) was not high. 6. The occlusal type according to the number of cusp was almost 5-cusp(98%) in the 1st molar and was also 5-cusp(63%) in the 2nd molar. The frequency of the 6th cusp was 31% in the 1st molar and was 22% in the 2nd molar. The frequency of the 7th cusp was below 2of in the both teeth. 7. In the buccolingual intercuspal distance aspect of the mesial and distal half, the intercuspal distance of distal half was higher than that of the mesial half on the 1st and 2nd molar, but the difference on the 1st molar was higher than that on the 2nd molar. 8. The difference between the widths of the buccal and lingual half was 1.5mm in the 1st molar and 0.8mm in the 2nd molar. Therefore the lingual convergency of the occlusal surface was more higher in the 1st molar. 9. On the mandibular 1st and 2nd molar, the distobuccal external angle was more acute than the mesiobuccal external angle. But the mesiobuccal internal angle was more acute than the distobuccal internal angle. 10. When the mandibular molar was a 5-cusp type, the development of the distal cusp on the 1st molar was better than that on the 2nd molar. The difference between the cusps was around 0.4mm.

• Restorative Dentistry and Endodontics
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• 제29권4호
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• pp.346-352
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• 2004

The purpose of present study was to evaluate the polymerization shrinkage stress and cuspal deflection in maxillary premolars resulting from polymerization shrinkage of composites and compomers. Composites and compomers which were used in this study were as follows: Dyract AP, Z100, Surefil. Pyramid, Synergy Compact, Heliomolar, Heliomolar HB, and Compoglass F. For measuring of polymerization shrinkage stress, Stress measuring machine (R&B, Daejon, Korea) was used. One-way ANOVA analysis with Duncan's multiple comparison test were used to determine significant differences between the materials. For measuring of cuspal deflection of tooth, MOD cavities were prepared in 10 extracted maxillary premolars. And reduction of intercuspal distance was measured by strain measuring machine (R&B, Daejon, Korea) One-way ANOVA analysis with Turkey test were used to determine significant differences between the materials. Polymerization shrinkage stress is $\mathbb{\ulcorner}$Heliomolar, Z100, Pyramid < Synergy Compact Compoglass F < Dyract AP < Heliomolr HB, surefil$\mathbb{\lrcorner}$ (P < 0.05). And cuspal delfelction is $\mathbb{\ulcorner}$Z100, Heliomolar, Heliomolar HB, Synergy Compact Surefil. < Compoglass F < Pyramid, Dyract AP$\mathbb{\lrcorner}$ (P < 0.05). Measurements of ploymerization shrinkage stress and those of cuspal deflection of the teeth was different. There is no correlation between polymerization shrinkage stress and cuspal deflection of the teeth(p > 0.05).

• Journal of Oral Medicine and Pain
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• 제15권1호
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• pp.105-115
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• 1991

The purpose of the study was to evaluate the occlusal stability at the moment of dynamic occlusal tooth contact and to investigate the correlation between the occlusal stability and the masticatory muscle activities. It also evaluated the effect of short-term use of occlusal splints on the occlusal stability and the masticatory muscle activities in patients with temporomandibular disorders during maximum voluntary clenching by synchondronized with temporomandibular disorders during maximum voluntary clenching by synchronized use of the T-Scan system(Tekscan, Inc, USA) and K6-Diagnostic system(Myo-tronics Research, Inc, USA) The author measured its distance from retruded contact position(RCP) to intercuspal position(IP), average of contact intervals(ACI), total left-right statistics(TLR), average muscle activities of masseter and anterior temporal muscles during maximum voluntary clenching in 20 patients with temporomandibular disorders and 22 dental students as a control group. The data were compared between two groups and investigated for any correlations between the parameters. The results were as follows : 1. Both of the mean average of contact intervals and the mean absolute value of total left-right statistics during maximum voluntary clenching were increased in the patient group when compared with the control group. 2. Muscular disharmony of anterior temporal muscles of patient group is significantly greater than that of control group. However, muscular disharmony of masseter muscles of patient group is not significantly greater than that of control group. 3. There were significant correlations between muscular disharmony of anterior temporal muscles and average of contact intervals as well as total left-right statistics, and also between muscular disharmony of masseter muscles and total left-right statistics. 4. There were not any significant correlations between distance from RCP to IP and any other parameters. 5. There were a significant decrease in total left-right statistics and muscular disharmony of anterior temporal muscles during maximum voluntary clenching after a 1week use of occlusal splint in the patient group.

• Restorative Dentistry and Endodontics
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• 제18권2호
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• pp.395-411
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• 1993

The purpose of this study was to examine the clear concept of the designs for cavity preparations. Among the several parameters in cavity designs, profound understanding of isthmus width factor would facilitate selection of the appropriate cavity preparation for a specific clinical situation. In this study, the cavities were prepared on maxillary first premolar and filled with gold inaly. A two - dimensional model was composed of 1037 - node triangle elements. In this model, isthmus was varied in width at 1/4, 1/3 and 1/2 of intercuspal width and material properties were given for four element groups, i.e., enamel, dentin, pulp and gold. The 500N occlusal load varied in direction and it was examined using three types of load : concentrated load, divided load and distributed load. The models were also examined with empty cavities using the devided load and distributed load. These models were analyzed the displacement and strees distribution by the two - dimensional Finite Element Method. The results were as follows : 1. All experimental models which filled with gold inlay after cavity preparation were similar direction of displacement with control model under same load type. But in the models with empty cavities, as isthmus width was wider, the degree of displacement was increased at same load type. 2. Among the experimental models which were filled with gold inaly after cavity preparation, the model II showed the least stress concentration under concentrated load and divided load. But in the models with empty cavities, the model III showed the largest stress concentration and tooth fracture is expected regardless isthmus width. 3. All experimental models showed similar displacement pattern beneath restorative material under a concentrated load. In the models with empty cavities, a divided load resulted in a lingual displacement of the lingual cusp, but a distributed load resulted in a buccal displacement of the lingual cusp. In regard to the above results, the restored models were stronger than empty models in respect to the bending moment and tensile stress. The empty models are expected to fracture regardless isthmus width. The safest isthmus width was 1/3 of intercuspal distance, which showed the least stress concentration in respect to the effect of stress distribution.

• 대한치과보철학회지
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• 제62권2호
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• pp.113-122
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• 2024

연령 증가에 따른 치아의 점진적인 마모는 자연적인 현상이나 생리적인 정도를 넘어 과도하게 발생하게 되면 수직 고경 상실, 교합 부조화, 악관절 질환, 치수병변 등을 일으킬 수 있어 보철물 수복이 필요하며, 이 때 적절한 수직 고경 거상과 함께 중심위(Centric Relation, CR)에서의 안정적인 교합 설정이 중요하다. 본 증례는 이 악물기와 이갈이 습관이 있는 74세 남환이 과도한 치아 마모를 주소로 내원하였고 이에 악간 거리, 마모 정도, 발음, 안모 평가 등을 시행한 결과 4 mm 수직 고경 거상을 동반한 전악 고정성 보철 수복을 진행하기로 하였다. 또한 비기능 하악 운동으로 인해 반복 재현성이 크게 떨어진 최대교두간 접촉위(Maximum Intercuspal Position, MICP)를 중심위에서의 안정적인 교합과 전‧측방 유도 시 상호보호교합이 되도록 적절히 형성해 주었다. 4개월간 임시 수복물에 적응한 것을 확인한 후 최종 보철물을 제작하였고 이후 4개월간 관찰한 결과 기능 및 심미적으로 결과를 만족하였기에 이를 보고하고자 한다.