• Maxillofacial Plastic and Reconstructive Surgery
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• v.39
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• pp.4.1-4.7
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• 2017

Background: This study is a quantitative evaluation of the influence of the mentolabial angle on perceived attractiveness and threshold values of desire for surgery. Methods: The mentolabial angle of an idealized silhouette male Caucasian profile image was altered incrementally between $84^{\circ}$ and $162^{\circ}$. Images were rated on a Likert scale by pretreatment orthognathic patients (n = 75), lay people (n = 75) and clinicians (n = 35). Results: A mentolabial angle of approximately $107^{\circ}$ to $118^{\circ}$ was deemed the most attractive, with a range of up to $140^{\circ}$ deemed acceptable. Angles above or below this range were perceived as unattractive, and anything outside the range of below $98^{\circ}$ or above $162^{\circ}$ was deemed very unattractive. A deep mentolabial angle ($84^{\circ}$) or an almost flat angle ($162^{\circ}$) was deemed the least attractive. In terms of threshold values of desire for surgery, for all groups, a threshold value of ${\geq}162^{\circ}$ and ${\leq}84^{\circ}$ indicated a preference for surgery, although clinicians were least likely to suggest surgery. The clinician group was the most consistent, and for many of the images, there was some variation in agreement between clinicians and lay people as to whether surgery is required. There was even more variability in the assessments for the patient group. Conclusions: It is recommended that in orthognathic and genioplasty planning, the range of normal variability of the mentolabial angle, in terms of observer acceptance, is taken into account as well as threshold values of desire for surgery. The importance of using patients as observers in attractiveness research is stressed.

• The korean journal of orthodontics
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• v.27 no.5 s.64
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• pp.723-732
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• 1997

The purpose of this study was to investigate the variations of the soft tissue profile contour in relation to the skeletal patterns and to confirm the correlation of soft tissue angles to the sagittal or vertical skeletal elements. Lateral cephalograms of 79 cases which were older than 17 years in age, were traced and statistically analyzed. The obtained results were as follows : 1. Nasolabial, interlabial, lower lip, mentolabial, and symphyseal angles showed the significant differences between skeletal Class II and skeletal. Class III group, but nasofrontal, upper lip, mentolabial, and symphyseal angles showed the significant differences between high angle and low angle group. 2. ANB value showed the significant positive correlation to nasolabial, symphyseal, and interlabial angles and the significant negative relation to lower lip angle. 3. SN-GoMe value showed the significant positive correlation to mentolabial, symphyseal, nasofrontal, and upper lip angles. 4. Soft tissue profile contour in SK. Class II group showed greater accordance to SN-GoMe value than those in SK. Class III group.

• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.1
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• pp.21-31
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• 2018

This study aimed to investigate the correlation between the inclinations of the incisors and lips in mixed dentition aged 7 - 11 years. Lateral cephalometric radiographs of 353 children were analyzed to measure the upper incisor inclination, lower incisor inclination, lower-nasolabial angle, and mentolabial angle in relation to the skeletal malocclusion classification. The measurements were then assessed using the Kruskal-Wallis test, Pearson correlation, and multiple regression analysis. There were significant negative correlations between the inclination of the upper incisors and lower-nasolabial angle in all classes of skeletal malocclusion. There was a negative correlation between the inclination of the lower incisors and mentolabial angle; however, class II malocclusion had a significant positive correlation. This study identified the factors that affect lip inclination and verified their associations.

• The korean journal of orthodontics
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• v.44 no.4
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• pp.184-194
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• 2014

Objective: To evaluate the relative importance of bilabial prominence in relation to other facial profile parameters in a normal population. Methods: Profile stimulus images of 38 individuals (28 female and 10 male; ages 19-25 years) were shown to an unrelated group of first-year students (n = 42; ages 18-24 years). The images were individually viewed on a 17-inch monitor. The observers received standardized instructions before viewing. A six-question questionnaire was completed using a Likert-type scale. The responses were analyzed by ordered logistic regression to identify associations between profile characteristics and observer preferences. The Bayesian Information Criterion was used to select variables that explained observer preferences most accurately. Results: Nasal, bilabial, and chin prominences; the nasofrontal angle; and lip curls had the greatest effect on overall profile attractiveness perceptions. The lip-chin-throat angle and upper lip curl had the greatest effect on forehead prominence perceptions. The bilabial prominence, nasolabial angle (particularly the lower component), and mentolabial angle had the greatest effect on nasal prominence perceptions. The bilabial prominence, nasolabial angle, chin prominence, and submental length had the greatest effect on lip prominence perceptions. The bilabial prominence, nasolabial angle, mentolabial angle, and submental length had the greatest effect on chin prominence perceptions. Conclusions: More prominent lips, within normal limits, may be considered more attractive in the profile view. Profile parameters have a greater influence on their neighboring aesthetic units but indirectly influence related profile parameters, endorsing the importance of achieving an aesthetic balance between relative prominences of all aesthetic units of the facial profile.

• The korean journal of orthodontics
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• v.32 no.5 s.94
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• pp.355-360
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• 2002

After orthodontic treatment, there are several changes in soft tissue profile. Changes appear at lower anterior facial profile area, especially upper and lower lip. But there are many individual variations in the pattern of changes. So, this study was conducted to find out that the basic upper lip thickness could be one of the factors that could influence the treatment results. The samples were composed of 43 adult patients who had their 4 first premolars extracted. Groups were classified by their basic lip thickness. In group 1(thin upper lip group), there was negative relationship between mentolabial angle and lower lip change. In group 2(average lip thickness group), upper lip change was related to upper incisor change, lower incisor change, lower lip change and nasolabial angle change. And lower lip change was related to upper lip change, upper incisor change, lower incisor change. In group 3(thick upper lip group), there was no relation between both lip change and other variables.

• The korean journal of orthodontics
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• v.22 no.4 s.39
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• pp.881-920
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• 1992

This study was designed to assess profile preferences among Korean youths in the year 1992. Facial esthetics was evaluated by means of silhouette profiles, eliminating the influence of a number of aspects that may affect judgment when normal lateral photographs are used. The main points of preference to be clarified here are as follows. First, on facial convexity, Second, on nasion depth, Third, on mentolabial sulcus depth, Fourth, on the position of upper and lower lips, Fifth, on facial type according to Angle's classification of malocclusion, Sixth, on Song's tangents. The 54 subjects printed in questionnaire as black and white silhouettes were selected from 300 tracings from cephalometric radiographs of people whose age ranging from 11 to 20 years. Photographs of six female subjects were retouched by computer graphic software and printed in color and black/white photographs which were used for adaptation of eyes of participants in selecting profiles in silhouette. They constitute 2 questions. The 54 subjects were grouped as 22 questions, each of them composed of 6 subjects, according to the aspects to be clarified. Twenty four questions in total were asked to assess profile preferences. For the assessment, the profile line, the facial esthetic triangle, Song's tangents, and Angle's classification of malocclusion were introduced. The profile line is composed of 11 component points which are Trichion, Glabella, Nasion, Pronasale, Subnasale, Labrale superius, Stomion, Labrale inferius, Supramentale, Pogonion, and Gnathion. The facial esthetic triangle is composed of 3 tangents: A-tangent which is the tangent of dorsum of nose, B-tangent which is the line passing through Sn and Ls, and C-tangent which is drawn on the turning point of the curve which lies between mentolabial sulcus (Sm) and pogonion (Pg). Angle's classification has 3 types of malocclusion which are Class I, Class II, and Class III. Class II malocclusion is subdivided into Division 1 and Division 2. The participants of the survey were composed of 861 college students (448 male students, 413 female students) whose majors grouped as Fine Arts. Liberal Arts, and Natural Sciences, and whose mean age 21.8 years. The statistics program SPSS/PC + of SPSS Inc. was used to analyze answers of participants. Crosstabulation, Chi-square test, and Kendall test were done. The conclusions are as follows: First, Korean youths have a tendency to prefer the slightly convex face to the flat or concave face. Second, they prefer a moderately deep nasion. Third, they prefer a moderately deep mentolabial sulcus. Fourth, they prefer the position of lips which are near to Ricketts' E-line. The position of the upper lip which is slightly posterior to E-line is preferred. The upper lip which lies too far anterior or posterior to the lower lip is not perferred. Fifth, they prefer most, according to Angle's Classification of Malocclusion, Class I facial profile which has a slight inclination to Class II division 2. The order of preference is Class I, Class II division 2, Class III, and Class II division 1. Sixth, they prefer the type 2 and 3 of Song's tangents. The facial profile within which A-and B-tangent meet is preferred. The facial profile which has Cotangent that .meets with A-tangent slightly posterior to the crossing point of A-and B-tangent or that parallels with B-tangent is preferred.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.49 no.6
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• pp.365-368
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• 2023

The mentum plays an important role in the aesthetics of the face, and genioplasty is performed to improve an unbalance of the mentum. Among the various surgical approaches, setback genioplasty is used to create an aesthetic jaw-end appearance by moving the mentum backward when it protrudes more than normal. However, conventional setback genioplasty may be aesthetically disadvantageous because the profile of the mentum could become flat. This case study attempted to overcome the limitations of conventional setback genioplasty by rotating the position of the menton and pogonion. We devised a new method for setback genioplasty by rotating the segment anteroinferiorly. Using virtual surgery, we were able to specify the range of surgery more accurately and easily, and the surgery time was reduced. This case report showed the difference in chin soft tissue responses between conventional setback genioplasty and setback genioplasty with rotation.

• The korean journal of orthodontics
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• v.26 no.2 s.55
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• pp.141-151
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• 1996

This study was undertaken to assess the effect of growth on the lips. Not only does lip growth influence the stability of such orthodontic treatment; it also directly influence facial profile, in which the lips have an important part. An understanding of the growth of lips is thus central to a consideration of profile change in orthodontics. By analyzing the serial lateral cephalograms of 15 male and 15 female of 8 years old to 16 yaers old who have normal occlusion. The result of this study were summerized as follows; 1. The largest growth increments in the length of the lips was mod age of 14 in both sexes. 2. The thickness of lips showed lager value for the male than that of the female in the most age group. The lagest growth increments at A point was occured age of 14, while Ls, Li, B point decreased after the age of 10-11. 3. The largest increase in the interval between crest of lower lip and edge of upper incisors was occured between ages 9 and 11 in males. The interval decreased slightly from 8 to 16 years in females. 4. The nasolabial angle decreased slightly from 8 to 16 years in both sexes. 5. The mentolabial angle showed large variation.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.22 no.2
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• pp.174-183
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• 2000

This study was performed to investigate the characteristics of soft tissue profile of the class III malocclusion and to test the yardstick far differential diagnosis between surgical and orthodontic patients. Initial lateral cephalograms of orthodontic group(30 patients) that have acceptable occlusion and profile by orthodontic treatment alone and surgical group(30 patients) that have favorable occlusion and profile by combined surgical-orthodontic treatment were selected in Ajou university hospital. Powell and Burstone II analysis were made on the tracing. Descriptive, comparative, factor, cluster, and discriminant analysis were carried out with computer program. The results were as followings : 1. Patients who received surgery had a more concave profile and a longer lower facial height than patients who received orthodontic treatment alone. 2. Nasolabial angle, ratio of vertical height, and mentolabial sulcus were significantly different at the 5% level. And facial protuberance, upper lip protuberance, mentocervical angle, nasofrontal angle, nasomental angle, mandibular vertical height, angle between cervix and lower face, ratio of mandibular vertical height divided by cervical depth, ratio of vertical height between upper and lower lip, and maxillary protuberance were significantly different at the 1% level. 3. 8 factors were extracted and factor 2, 3, and 8 showed significant differences by factor analysis. 4. Orthodontic group (25) and surgical group (35) were classified by cluster analysis. 5. Discriminant function was D = 0.079Nasomental angle + 0.081Sn-Gn + 3.343Sn-Gn/C-Gn + 1.734Sn-St/St-Me' -26.460, and cutting score was 0, so we can discriminate that orthodontic group has the score above 0, and surgery group below 0. And 91.7% of original grouped cases were correctly classified.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.6
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• pp.559-565
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• 2006

The aim of this study was to evaluate the amount and interrelationship of the soft and hard tissue changes after simultaneous maxillary clockwise rotation and mandibular setback surgery in skeletal class III malocclusion. The sample comprised of 16 adult patients who had anteroposterior skeletal discrepancy. These patients had received presurgical orthodontic treatment and surgical treatment which consisted of Le fort I Osteotomy and bilateral saggital split ramus osteotomy. The presurgical (T1) and postsurgical (T2) lateral cephalograms were evaluated. The computerized statistical analysis was carried out with SPSS/PC program. The results demonstrated a decrease in the vertical dimension in the soft and hard tissue. The nasolabial angle was increased and the mentolabial angle was decreased. The results showed also many statistically significant correlations(p<0.05). The lower lip closely followed the skeletal movement of the B- point in the horizontal plane. The double jaw rotation surgery can afford a good solution to solve the problems of class III malocclusion cases.