• The Journal of Advanced Prosthodontics
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• 제5권1호
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• pp.58-66
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• 2013

PURPOSE. The purpose of this study was to decide the most appropriate point on tragus to be used as a reference point at time of marking ala tragus line while establishing occlusal plane. MATERIALS AND METHODS. The data was collected in two groups of subjects: 1) Dentulous 2) Edentulous group having sample size of 30 for each group with equal gender distribution (15 males, 15 females each). Downs analysis was used for base value. Lateral cephalographs were taken for all selected subjects. Three points were marked on tragus as Superior (S), Middle (M), and Inferior (I) and were joined with ala (A) of the nose to form ala-tragus lines. The angle formed by each line (SA plane, MA plane, IA plane) with Frankfort Horizontal (FH) plane was measured by using custom made device and modified protractor in all dentulous and edentulous subjects. Also, in dentulous subjects angle between Frankfort Horizontal plane and natural occlusal plane was measured. The measurements obtained were subjected to the following statistical tests; descriptive analysis, Student's unpaired t-test and Pearson's correlation coefficient. RESULTS. The results demonstrated, the mean angle COO (cant of occlusal plane) as $9.76^{\circ}$, inferior point on tragus had given the mean angular value of IFH [Angle between IA plane (plane formed by joining inferior point-I on tragus and ala of nose- A) and FH plane) as $10.40^{\circ}$ and $10.56^{\circ}$ in dentulous and edentulous subjects respectively which was the closest value to the angle COO and was comparable with the values of angle COO value in Downs analysis. Angulations of ala-tragus line marked from inferior point with occlusal plane in dentulous subject had given the smallest value $2.46^{\circ}$ which showed that this ala-tragus line was nearly parallel to occlusal plane. CONCLUSION. The inferior point marked on tragus is the most appropriate point for marking ala-tragus line.

• 대한치과보철학회지
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• 제27권1호
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• pp.25-29
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• 1989

The author analized 17 complete denture patients with lateral cephalometric roentgenograms and following results were obtained: 1. The angle between the Ala tragus line and the occlusal plane was $4.38^{\circ}$. 2. The angle between the Ala tragus line and the Frankfort horizontal plane was $13.68^{\circ}$. 3. The line between the mouth corner and the retromolar pad was more parallel to the occlusal plane than the Ala tragus line.

• The Journal of Advanced Prosthodontics
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• 제6권6호
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• pp.483-490
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• 2014

PURPOSE. The purpose of this study was to determine the average facial proportions and mandibular movement capacity of 316 first-year dental students who carefully recorded them on each other. MATERIALS AND METHODS. This early exacting clinical experience was closely supervised by the authors in Columbus, Ohio during 1969-70. Five vertical and six horizontal distances were measured on each subject's face. An ala-tragus line and an occlusal line were drawn on the left side of the face to determine if these two lines were parallel. Measurements of mandibular movements involved maximum normal and hinge opening at the incisors and maximum amounts of right, left lateral and protrusive excursions of the mandible. RESULTS. The ala width and distance between the tips of upper right and left canine cusps averaged (35.2 mm and 34.8 mm) but with very large individual variations. The distance between ala to occlusal plane lines was 29.9 mm at the tragus and 31.3 mm near the ala. The angle between orbitale and ala-tragus averaged 13.6 degrees. CONCLUSION. The upper lip length was the most variable and the distance between the pupils was the most stable of the eleven facial measurements. The ala-tragus line and the occlusal plane lines were for all practical purposes parallel. Maximum jaw opening averaged 51.2 mm which was 3.0 times larger than maximal hinge opening of 17.2 mm. The maximum right plus left side jaw excursions (9.2 and 9.4 mm) totaled 18.6 mm, 2.3 times more than the 8.0 mm mean maximum forward protrusion.

• The Journal of Advanced Prosthodontics
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• 제5권1호
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• pp.9-15
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• 2013

PURPOSE. The purpose of this study was to determine accurately the part of the tragus to be used to form the Ala-Tragal line or Camper's line in orthognathic profile patients. MATERIALS AND METHODS. 150 dentate subjects with age of 18-40 years with orthognathic profile were sampled. Life-size lateral digital photographs of the face with fox plane were taken in natural head position. Different angles between Eye-Ear plane and occlusal plane ($OT_1$-OP), Eye-Ear plane and ala-superior border of tragus ($OT_1-AT_1$), Eye-Ear plane and ala-middle border of tragus ($OT_1-AT_2$) and Eye-Ear plane and ala-inferior border of tragus ($OT_1-AT_3$) were calculated using computer software package, AutoCAD 2004. From the three angles formed by the Eye-ear plane ($OT_1$ or FH plane) and the ala-tragal lines, the one closest to the angle formed between Eye-Ear plane ($OT_1$) and occlusal plane (OP) was used to determine the occlusal plane of orientation. The obtained results were subjected to ANOVA F test, Tukey's Honestly significant difference test, followed by Karl Pearson coefficient of correlation test. P values of less than 0.05 were taken as statistically significant. RESULTS. The mean of base line angle i.e. $OT_1$-OP angle ($11.96{\pm}4.36$) was found to be close to $OT_1-AT_2$ angle ($13.67{\pm}1.93$) and $OT_1-AT_3$ angle ($10.31{\pm}2.03$), but $OT_1$-OP angle was found to be more closer to $OT_1-AT_3$ angle. Comparison of mean angles showed that $OT_1$-OP angle in both males (11.68) and females (12.51) is close to $OT_1-AT_3$ angle (males- 11.01, females- 11.95). CONCLUSION. The line joining from ala to the lower border of the tragus was parallel to the occlusal plane in 53.3% of the subjects. There was no influence of the sex on the level of occlusal plane.

• 대한치과보철학회지
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• 제30권4호
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• pp.575-581
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• 1992

It is a very important procedure to establish the occlusal plane in the construction of complete denture. So many methods have been utilized to establish the occlusal plane in complete denture prosthodontics. However, no single method seems to fully accepted. This study was aimed to review the literature on establishing the occlusal plane in complete denture prosthodontics, to measure the distance from the lower border of the upper lip to the upper incisal edge and to investigate the correlation between the ala-tragus line and the occlusal plane. The results ware as follows ; 1. The average distance between the lower border of the upper lip and the upper incisal edge was $1.45{\pm}1.28mm$. 2. The distance between the lower border of the upper lip and the upper incisal edge had a tendency to decrease with age. 3. A angle of the ala-tragus line to the occlusal plane measured with Fox plane was $-1.41{\pm}2.33^{\circ}$. 4. The ala-tragus line to occlusal plane was nearly parallel, cosidering curve of spee in the upper natural teeth.

• Imaging Science in Dentistry
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• 제38권2호
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• pp.73-79
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• 2008

Purpose: To assess the internal echo intensity and morphological variability of masseter muscles on ultrasonography and to establish diagnostic criterion of estimation. Materials and Methods: Participants consisted of 50 young adults (male 25, female 25) without pathologic conditions and with full natural dentitions. Sonographic examinations were done with real time ultrasound equipment as Logiq 500 (GE Medical Systems, Seoul, Korea) at 3 parts according to lines paralleling with ala-tragus line as reference line. The thickness and area of masseter muscles according to reference line in cross-sectional images were measured at rest and at maximum contraction. The visibility and width of the internal echogenic intensity of the masseter muscles were also assessed and the muscle appearance was classified into 4 types. Data were statistically analyzed by paired t-test and $x^2$-test. Results: 1. When comparing the thickness and area of masseter muscles concerning with gender, there was few significant difference between right and left sides, however, there were significant differences between males and females except for the greatest thickness of left side. 2. The changes of the greatest thickness and the area between rest and maximum contraction showed that the part of the least thickness manifested more increase at maximum contraction. 3. Each part the manifestations of the internal echogenic intensity of the masseter muscles were different depending on the locations. But there was no statistically significance. Conclusion: Changes of muscles thickness with contraction and internal echogenic intensity with locations showed great disparity within the masseter muscles, which will be diagnostic criteria for pathophysiologic and anatomic changes of masseter muscles.

• 대한치과보철학회지
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• 제33권4호
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• pp.769-779
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• 1995

The understanding the nature of occlusal tooth contacts of natural dentition is important for correct diagnosis and treatment of diseases developed in stomatognatic system. Several investigator have studied the distribution of tooth contacts in maximum intercuspation and have repored contact locations with respect to the tooth position. However, there are few report the variation of the occlusal contact point with change in each head position. This study analysed the number of occlusal contact point with change in each head position. 30 subject(male 17, female 13), who ahad natural occlusion and no symptoms of temporomandibular disorder, were selected. The numbers and patterns of tooth contact were recorded by silicone bite registration on stone model at four different head positions with head anguration gauge(from the supine to the upright position). The results obtained were as follows : 1. The numbers of total occlusal contact point on teeth increased to average 25, 29, 35, 42 points as head angulation was changed from the supine to the upright position against the ala-tragus line, and there was significant difference(P<0.05). 2. In the 19 subject(65%)of total 30 subject, the perforated point of the silicone bite indicated that the locus for the prime contact point moved mesially as the head angulation was changed from the supine to the upright position. 3. On the basis of the fact that the anterior occlusal contact point increase as head angulation changed from the supine to the upright position, we could find that the mandibular position is moved anteriorly.

• Journal of Oral Medicine and Pain
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• 제32권4호
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• pp.421-429
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• 2007

최근 tactile sensor 를 사용하여 근육의 경도와 탄성도를 조사하는 방법이 저작근의 새로운 평가방법으로 제시되고 있다. 본 연구의 목적은 촉각센서를 이용하여 일정시간 껌씹기를 시행전, 중, 후의 저작근의 경도와 탄성도를 조사하여 향후 턱관절 장애 환자의 저작근 평가를 위한 기초자료를 확보하는 데 있다. 건강한 성인 8명을 대상으로 양측 전측두근(anterior temporalis), 하교근(inferior masseter)의 경도와 탄성도를 촉각센서 (Venustron II, Axion Co., Japan)를 이용하여 다음과 같이 측정하였다. 피검자들을 unit-chair에 바로 앉힌 상태에서 양측 교근 및 측두근 부위를 촉진을 통해 전 측두근(temporalis anterior), 하 교근(masseter inferior) 두 부위를 펜으로 표시하였다. 실험의 재현성을 위하여 투명한 종이에 ala-tragus line을 표시한 후 두 부위를 투명종이 위에 표시하였다. 편안한 상태에서 촉각센서를 사용하여 양측 하 교근 및 전 측두근의 경도와 탄성도를 측정한 후, 껌(Excellent Breath, Taiyo Co., Japan)을 양측으로 씹게 하여 1초당 2회의 속도로 씹게 하였다. 껌을 40분동안 저작하는 동안 10분, 20분, 30분, 40분에 양측 하 교근 및 전 측두근의 경도와 탄성도를 측정하였다. 그 후 껌을 뱉게 하고 하악의 안정위 상태에서 10분, 20분, 30분, 40분 후 양측하 교근 및 전 측두근의 경도와 탄성도를 각각 측정하였다. 측정치들을 반복측정 이원분산분석과 다중비교를 통하여 비교하였다. 실험결과 측두근과 교근을 비교 시 탄성도, 경도 모두 교근의 변화가 유의하게 크다. 또한 저작하면 서서히 경도는 증가하며 탄성도는 반대로 감소한다. 탄성도 및 경도는 저작 시 신속히 증가하나 저작 종료 후에는 탄성도만 신속히 회복되나 경도는 약 10분 이상의 일정시간이 지나야 회복된다. 이상의 결과들을 보아 임상적으로 좀 더 다양한 연구와 기초자료가 확보된다면, 저작근의 근육 상태를 평가하는데, 근육의 탄성도와 경도를 조사하는 tactile sensor system은 유익한 기기로서 활용될 수 있을 것이다.