A study on the smile according to age and esthetic evaluation by the degree of dental knowledge

Seong-Jin Kim; Moon-Gwan Kim; So-Min Park; Jae-Sam Ban; Sang-Won Park

doi:10.4047/jkap.2012.50.4.249

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Kim, Kim, Park, Ban, and Park: A study on the smile according to age and esthetic evaluation by the degree of dental knowledge

Original Article

The Journal of Korean Academy of Prosthodontics

The Journal of Korean Academy of Prosthodontics 2012; 50(4): 249-257.

Published online: 30 October 2012

DOI: https://doi.org/10.4047/jkap.2012.50.4.249

A study on the smile according to age and esthetic evaluation by the degree of dental knowledge

Seong-Jin Kim, DDS, MDS, Moon-Gwan Kim, DDS, MDS, So-Min Park, DDS, MDS, Jae-Sam Ban, PhD, Sang-Won Park, DDS, PhD

Department of Prosthodontics, School of Dentistry, Chonnam National University, Gwangju, Korea.

Corresponding Author: Sang-Won Park. Department of Prosthodontics, School of Dentistry, Chonnam National University, 33 Yongbong-ro, Buk-gu, Gwangju, 500-757, Korea. +82 62 530 5630: psw320@chonnam.ac.kr

Received 27 July 2012 Revised 18 September 2012 Accepted 15 October 2012

(open-access):

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Purpose

This study was designed to help to provide the criteria of the esthetic smile in oromaxillary region on twenties, fifties and sixties.

Materials and methods

The facial straight photographs of 33 adults (male 15, female 18, mean age 27.2 years old) and 20 seniors (male 7, female 13, mean age 55.6 years old) in resting and smile position were taken. The measurements and proportion of lip-teeth relation during smile were statistically analyzed, and survey of freshmen and seniors who belong to School of Dentistry, Chonnam National University were taken to select the best esthetic smile among the photographs.

Results

In the relationship between the upper lip and the teeth, average smile was the most frequent, and mean of smile line ratio was 1.090 in young group and 0.90 in old group. The correlation between the buccal corridor ratio and exposed teeth count was inversed. At smile, most frequently exposed tooth was the second premolar (63.64%) in young gourp and the first premolar (35.00%) in old group. The correlation between the upper lip change ratio and exposed clinical crown length of maxillary central incisor was inverse, but there was no correlation between the lower lip change ratio and exposed clinical crown length of maxillarycentral incisor.

Conclusion

In the result of survey, the students selected the case exposed to the first premolar as the most esthetic smile. The most esthetic smile between full facial photograph and the lip only photograph by the freshmen was different, but that by seniors was identical.

Keywords: Smile, Esthetic, Anterior teeth, Survey

Figures and Tables

Fig. 1

Sample pictures taken at A: resting state, B: smile.

Fig. 2

Landmarks used to evaluate the patterns of the smile.

Fig. 3

Pictures for the questionnaire (A: Mouth, B: Face).

Table 1

Smile type (N, %)

High smile: exposed all Mx. Anterior teeth & gingival, Average smile: 70 - 100% of Mx. Anterior teeth, Low smile: less than 70% of Mx. Anterior teeth

Table 2

Smile line ratio

Smile line ratio: similar to 1 is regarded esthetic

Table 3

Correlation between buccal corridor ratio and number of exposed teeth

Table 4

Exposed teeth at smile (N, %)

Table 5

Mouth width and exposed teeth count at smile

Table 6

Correlation test between (mouth width/facial width) and exposed teeth count at smile

Table 7

Maxillary central incisor clinical crown length at smile (mm)

Table 8

Lip change ratio

Table 9

Correlation between buccal corridor ratio and number of exposed teeth

References

1. Kim SH, Suhr CH. A roentgenocephalometric study on the soft tissue of the children in mixed dentition. Korean J Orthod. 1985. 15:229–238.

2. Miller CJ. The smile line as a guide to anterior esthetics. Dent Clin North Am. 1989. 33:157–164.

3. Frush JP, Fisher RD. How dentogenicsinterprets the personalityfactor. J Prosthet Dent. 1956. 6:441–449.

4. Hulsey CM. An esthetic evaluation of lip-teeth relationships present in the smile. Am J Orthod. 1970. 57:132–144.

5. Tjan AH, Miller GD, The JG. Some esthetic factors in a smile. J Prosthet Dent. 1984. 51:24–28.

6. Yoon ME, Jin TH, Dong JK. A study on the smile in Korean youth. J Korean Acad Prosthodont. 1992. 30:259–271.

7. Kim HS, Jin TH, Dong JK. A study on the relation between lip and teeth at smile in old aged Korean. J Korean Acad Prosthodont. 1993. 31:533–541.

8. Shillingburg HT, Hobo S, Whitsett LD. Fundamentals of fixed prosthodontics. 1996. 2nd ed. Chicago: Quintessence Int.

9. Lombardi RE. Factors mediating against excellence in dental esthetics. J Prosthet Dent. 1977. 38:243–248.

10. Renner RP. An introduction to dental anatomy and esthetics. 1985. Chicago: Quintessence Int;241–273.

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