J Korean Acad Prosthodont.  2012 Jul;50(3):162-168. 10.4047/jkap.2012.50.3.162.

A study on the smile of Korean Youth compared with twenty years ago

• Beom SG
• Jung JH
• Kim TY
• Lee KE
• Dong JK

• KMID: 2000204
• DOI: http://doi.org/10.4047/jkap.2012.50.3.162

Abstract

PURPOSE
Teeth are generally exposed when people smiling. Moreover, the exposed teeth and soft tissue when smiling becomes an important guideline for esthetically prosthetic restoration. This research is to compare and find out differences of Korean young men's smile living in presence and twenty years ago.
MATERIALS AND METHODS
Subjects, 100 young men (50 male and 50 female), were required about several aspects; normally developed physical condition, no psychological or genetic disorders, a fine face with no loss of teeth, no experience in orthodontic or prosthetic treatment, relatively normal occlusion, aged between 20 - 29. The photos of the subject at rest position and front face when fully smiled were taken three times. 100 photos (50 male and 50 female) were chosen at random from the 240 university students' smile photos taken by Yoon and his colleagues in 1991. By Hulsey's method of measuring smile, several factors; the change of upper lip curvature, the change of the relation between the upper lip and teeth, parallelism between Mx. incisor and lower lip, contact relation between Mx. incisor and lower lip and teeth displayed in a smile, were measured and analyzed. Meanwhile, ten dentists assessed aesthetic evaluation about men and women's smile for twice and recorded and compared smile score. The -test (P<.05) was used to compare the measured value. The difference of smile score was analyzed by t-test (P<.05).
RESULTS
The smile score calculated in 2011 (60.22) was higher than that of 1991 (52.80). Among five measurement categories, the noticeable difference was distinguished from two factors; the change of upper lip curvature and contact relation between Mx. incisor and lower lip.
CONCLUSION
The Korean young men's smile has been considerably improved for twenty years. And it is found that the change of upper lip curvature plays an important role, that is, the smile formed with an ascended labial commissure has been increased significantly.

Keyword

Smile type; Smile score; Upper lip curvature

MeSH Terms

Adolescent
Aged
Dentists
Humans
Incisor
Lip
Male
Smiling
Tooth

Figure

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  Fig. 1 Comparison of upper lip curvature (P<.05).

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  Fig. 2 Comparison of the relation between the upper lip and the teeth (Smile type) (P>.05).

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  Fig. 3 Comparison of the parallel relation between the lower lip and maxillary andterior incisal curvature (P>.05).

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  Fig. 4 Comparison of the relationship between maxillary anterior incisor and lower lip (P<.05).

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  Fig. 5 Comparison of the teeth displayed in a smile (P>.05).

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