• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.1
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• pp.85-93
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• 2019

Oil seals are most essential parts in mechanical lubrication system to maintain the close gaps between stationary and high rotating components, and to help prevent oil leakages. Oil seals also can prevent harmful contaminants entering from outside to machinery, especially in severe environments. Therefore, the oil seals have an important performance in the machinery components. The performance of the oil seals are influenced by the design variables such as amount of interference gap between the main lip and shaft, the angle of main lip at air and oil sides and the distance between the garter spring and main lip. In the present study, a finite element analysis was performed to evaluate the oil seal performance with the considerations of number of oil seal dust lips and angle of the lip at oil side with the different design variables. As a result from the FEM analysis, the stress and contact pressure distributions was derived, based on this, performance of the sealing and durability were determined.

• International Journal of Aerospace System Engineering
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• v.7 no.2
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• pp.1-5
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• 2020

When a rigid wedge is indented in to a semi-infinite block, the material is bulged up around the wedge that is generally called lip. The previous works in this filed considered the outer profile of the lip to be linear. But, present authors observed both experimentally and with the aid of finite element analysis that the profile of the lip is not always linear, and it depends on the angle of the wedge and friction parameters. So, in this work, attempts have been made to calculate hardness of indentation for different wedge angles and friction parameters. As hardness is intrinsic property of material, consideration of either linear or parabolic lip will not be affected much. A comparative study of hardness for linear and parabolic free surface profiles of the piled up material around the cone is analyzed in this work.

• Korean Journal of Cleft Lip And Palate
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• v.5 no.1
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• pp.27-42
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• 2002

This study was designed to evaluate the morphology and the position of the mandible in the complete unilateral cleft lip and palate patients, Craniofacial skeletal morphology pattern was analyzed on the lateral cephalometric radiographs of the 50 subjects of complete unilateral cleft lip and palate, the 50 normal and 50 class III, Each group was divided into child and adult sub-groups, All the data were tested statistically. The results were as follows: I, In the comparison with the normal group, complete cleft group showed smaller angular, condylar length, clockwisely rotated mandible and larger NMe/SGo(p<0.01). 2, In the comparison with the class III group, the complete cleft group showed significantly smaller angular, condylar, ramal, body length of the mandible(p<0,01). 3. As for the position of the mandibular condyle to the cranial base, the class III group was the most anterior, the normal group was the most posterior and the complete cleft group was in the middle(p<0.05). 4. In the comparison with child group, the normal adult group showed smaller mandibular angle and mandibular plane angle, but not the other two groups. And the complete cleft group and the class III group showed the similar change. The normal and class III group showed increased XiCd/XiPog, but not the complete cleft group(p<0.01).

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.6
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• pp.643-647
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• 2007

Purpose: The purpose of study was to investigate the correlationship between lip canting change and occlusal canting change after bimaxillary orthognathic surgery, and the ratio of lip canting change and occlusal canting change after the surgery. Patients and methods: The subjects for this study was obtained from a group of 25 patients who took bimaxillary orthognathic surgery for occlusal canting correction at the Department of the Oral and Maxillofacial Surgery, Samsung Medical Center in Seoul, Korea between January 2000 and December 2005 and a patient's chart had to contain a resting frontal facial photograph in natural head position and a corresponding PA cephalogram in occlusion on the same day before the surgery and post-op 6 months later. The lip canting change was assessed with the angle each labial commissure and the bipupilary reference line. And, the occlusal caning change in the frontal plane was assessed with the angle between the each maxillary first molar occulasal surface and the bi-frontozygomatic suture reference line. Results: In angular measurement, average occlusal canting change was $3.09^{\circ}$ and standard deviation was $1.05^{\circ}$, average lip canting change was $1.56^{\circ}$ and standard deviation was $1.05^{\circ}$. In linear measurement, average occlusal canting change was 2.41mm and standard deviation was 2.75mm, average lip canting change was 1.18mm and standard deviation was 0.43mm. Lip canting correction ration to occlusal canting correction was 51.5(${\pm}8.4$)% in angular measurement and 48.8(${\pm}9.1$)% in linear measurement. Under Pearson's correlation analysis, Pearson's correlation coefficient was 0.869 in angular measurement and 0.887 in linear measurement(p-value < 0.01). High correlationship was shown between occlusal canting change and lip canting change. Conclusion: First, Bimaxillary orthognathic surgery can correct lip canting as well as occlusal canting. Second, The average amount of lip canting correction is $51.5{\pm}8.4%,\;48.8{\pm}9.1%$ of occlusal canting correction in the study.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.22 no.3
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• pp.310-318
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• 2000

The purpose of this study was to assess the soft tissue changes of upper lip & nose using 38 patients who treated with Le Fort I osteotomy for the correction of dentofacial deformities. Patients were devided into three groups. One was advancement group of maxilla(Group I, N=14), another was impaction group of maxilla(Group II, N=12) and the other was combination group(advancement & impaction)(Group III, N=12). Preop. and 1 month postop. (T1), preop. and 6 months postop.(T2) were analyzed and compared. The results obtained were as follows : 1. The upper lip thickness(UL-VP) moved anteriorly approximately 62% of the horizontal maxillary change and this was significant in the advancement group(Group I) 2. The upper lip length(Stm-Sn) and the lower border of upper lip(Stm) moved superiorly 25%, 40% of the maxillary impaction group(Group II) (P<0.05) 3. There was significancy in the upper lip thicness(UL-VP) approximately 56% of the combination group(Group III) (P<0.05) 4. The nasolabial angle decreased in all groups, but there were no significancy.

• Elastomers and Composites
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• v.48 no.4
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• pp.282-287
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• 2013

Slot coating has been widely spread in photo resist coating on glass for flat display monitor. High quality of coating is required as high quality of image in display is needed. Coating quality in the slot coating is divided into nozzle direction quality and machine direction quality. Nozzle direction quality is related to flow uniformity inside the die whereas machine direction quality is related to die lip design and operational conditions. In this study coating uniformity in the machine direction of slot coating has been investigated through computer simulation. Die lip angle and die lip length were considered as outside die geometry and coating speed was considered as operational condition. Coating behavior has been analyzed and coating quality has been evaluated through computer simulation. Coating thickness decreased and coating uniformity increased as coating speed increased. However, the stability of meniscus formation was reduced and subsequently coating stability was reduced as coating speed increased. Coating thickness deviation decreased as die lip angle increased in down stream die. Coating thickness decreased and time to reaching steady state increased as increased die lip length in down stream die.

• Archives of Plastic Surgery
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• v.40 no.1
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• pp.62-65
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• 2013

The philtrum plays a key role in the appearance of the upper lip and nostril sill. Therefore, construction of the philtrum is crucial for attaining a natural appearance of the upper lip. We used a flipping myoplasty of the orbicularis oris muscle on a patient with a flat philtrum in order to effectively reconstruct the philtral dimple and column. A 35-year-old female presented to our department with the complaint of a flat upper lip. A superficial layer of the orbicularis oris muscle on the median aspect of the upper lip was vertically incised and elevated to a thickness of 2 mm. Both sides of the elevated muscle flap were then folded to the lateral sides so that the border could be sutured onto the outer portion of the orbicularis oris muscle. The patient was observed for one year postoperatively. Her philtrum deepened by 1.25 mm, with the central angle of her Cupid's bow improving from a preoperative measurement of $146^{\circ}$ to $128^{\circ}$ postoperatively. In a patient with an indistinct philtrum, a flipping orbicularis oris myoplasty was performed to attain a definite philtral column and a philtral dimple. Natural upper lip movement was maintained, and an aesthetically and functionally satisfactory reconstruction was achieved.

• Journal of the korean academy of Pediatric Dentistry
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• v.46 no.4
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• pp.343-352
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• 2019

Abnormal orofacial functions such as lip incompetency in the period of growth and development can cause morphological anomalies of the craniofacial complex. Therefore, it is crucial to make an early diagnosis based on the evaluation of the myofunctional conditions, and to make appropriate treatment plans. The objectives of this study were to quantitatively evaluate the standard lip closing force (LCF) of each age in the elementary school children, and to evaluate the relationships between LCF and affecting factors. The sample consisted of 765 children who were 7 - 12 years old in Jeonju city. Clinical examination about occlusal conditions and lip competency, and LCF measurement were performed by a single examiner. LCF was measured three times for each children with the LCF measuring device. The LCF was correlated positively with age in both sexes. The distribution of LCF groups was correlated significantly with Angle's classes and lip competency (p = 0.016, 0.004). The proportion of children with high LCFs was greater in the "competent lip" group, whereas the proportion of those with low LCFs was greater in the "incompetent lip" group.

• The korean journal of orthodontics
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• v.22 no.3 s.38
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• pp.657-673
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• 1992

Orthodontic treatment of cleft patients is difficult as the growth is different from that of normal ones. So it is very important to know the characteristic features of the craniofacial morphology and growth pattern in unilateral cleft lip and palate patients. The materials for this study consisted of 55 normal males and 50 unilateral cleft lip and palate ones who received cheiloplasty and palatoplasty previously. The cleft subjects were divided into 4 groups according to their ages kto find out the growth pattern of hard and soft tissue, and to compare the features with those of normal ones. Each cephalogram analysed by McNamara method and others. The obtained results were as follows 1. In the unilateral cleft lip and palate subjects, forward growth of the maxilla was smaller than that of normal ones from 9 years old. So the maxilla was retruded. The maxillary incisors were severely retruded in all age groups. 2. The mandibular overall length and its anteroposterior position did not show any significant differences between two groups. But the height of ramus was very short and the mandible had vertical growth tendency to compensate for undergrowth of the maxilla in cleft subjects after 12 years of age. 3. Horizontal growth of the soft tissue in middle face was smaller than that of any other facial region from 9 years old. The vertical growth rate of upper lip was decreased as growing old. 4. In cleft subjects, the upper and lower facial component angle and the facial convexity angle were large. So their facial profile changed to straight or concave as growing old.

• The korean journal of orthodontics
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• v.50 no.2
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• pp.120-128
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• 2020

Objective: The aims of the present study were to evaluate the changes in the maximum lip-closing force (MLF) after orthodontic treatment with or without premolar extractions and verify the correlation of these changes with dentoskeletal changes. Methods: In total, 17 women who underwent nonextraction orthodontic treatment and 15 women who underwent orthodontic treatment with extraction of all four first premolars were included in this retrospective study. For all patients, lateral cephalograms and dental models were measured before (T0) and after (T1) treatment. In addition, MLF was measured at both time points using the Lip De Cum LDC-110R^® device. Statistical analyses were performed to evaluate changes in clinical variables and MLF and their correlations. Results: Both groups showed similar skeletal patterns, although the extraction group showed greater proclination of the maxillary and mandibular incisors and lip protrusion compared to the nonextraction group at T0. MLF at T0 was comparable between the two groups. The reduction in the arch width and depth and incisor retroclination from T0 to T1 were more pronounced in the extraction group than in the nonextraction group. MLF in the extraction group significantly increased during the treatment period, and this increase was significantly greater than that in the nonextraction group. The increase in MLF was found to be correlated with the increase in the interincisal angle and decrease in the intermolar width, arch depth, and incisor-mandibular plane angle. Conclusions: This study suggests that MLF increases to a greater extent during extraction orthodontic treatment than during nonextraction orthodontic treatment.