Get Permission Choudhary, Sharma, Kumar, and Jain: Evaluation of smile esthetics in adults with different overjets

Journal Information

Journal ID (nlm-ta): Innovative Publication

Journal ID (publisher-id): Innovative Publication

Journal ID (journal_submission_guidelines): https://www.innovativepublication.com/journal/JDS

Title: Journal of Dental Specialities

ISSN: 2393-9834

Article Information

Copyright: 2020

Date received: 23 August 2020

Date accepted: 10 October 2020

Publication date: 21 July 2021

Volume: 8

Issue: 2

DOI: 10.18231/j.jds.2020.018

Evaluation of smile esthetics in adults with different overjets

[] Priyanka Choudhary[1]

Email: cpriyanka864@gmail.com

Designation:

Post Graduate Student

[] Payal Sharma[1]

Designation:

HOD

[] Piush Kumar[1]

Designation:

Professor

[] Shubhangi Jain[1]

Designation:

Senior Lecturer

 

Dept. of Orthodontics & Dentofacial Orthopedics, I.T.S Centre for Dental Studies and Research, Muradnagar Ghaziabad, Uttar Pradesh India

Abstract

Aim: Our aim was to quantitatively assess the relationship of smile esthetics variables with various types of anterior overjet (OJ) malocclusion, and identify the cephalometric factors affecting smile measurements in different types of anterior overjet malocclusion.

Materials and Methods: 90 patients undergoing orthodontic treatment in the Department of Orthodontics were selected for this retrospective study based upon the inclusion criteria. The patients were divided into the following groups according to their OJ: Group 1 (0-4mm), Group 2 (>4mm), Group 3 (<0mm).

Results: The upper lip height, and inter-labial gap differed significantly among the groups, whereas arc ratio, tooth number, upper midline, buccal corridor, smile index, arch form index and lower tooth exposure did not significantly among the groups.

Conclusion: Some smile variables (upper lip height, inter-labial gap) differed significantly among different types of anterior overjet malocclusion. This study confirmed that the smile pattern varies between different types of malocclusion.

Introduction

One of the most essential expressions that contributes to facial attractiveness is the smile. And one of the most common reasons individuals seek orthodontic treatment is to improve the appearance of their smile. Understanding the elements of an aesthetically pleasing smile is critical for patient happiness and good treatment outcomes.1

The quantity of gingiva shown in the smile arc, as well as the color of the teeth, influence the aesthetics of a smile. A smile with little gingival display is thought to be more attractive than one with considerable gingival display. A smile with a curvature of the maxillary incisal edges (smile arc) that mirrors the curvature of the lower lip is thought to be more attractive than one with a flat maxillary incisal edge connection. A light shade of teeth, as well as the coincidence of the maxillary midlines with the face midlines, has been determined to be crucial. The presence or absence of buccal corridors is another potentially relevant smiling feature.2, 3, 4, 5

Several studies on the aesthetics of smiles have been carried out. However, only a few clinical investigations have looked at the impact of various types of malocclusion on smile esthetics. As a result, the goal of this study was to quantify the association between smile esthetic features and various forms of anterior overjet (OJ) malocclusions, as well as to determine the cephalometric elements that influence smile measurements in various types of anterior overjet malocclusions.6, 7, 8

Materials and Methods

The study was conducted after the ethical approval of the institutional committee. 90 patients undergoing orthodontic treatment in the Department of Orthodontics were selected for this retrospective study based upon the following inclusion criteria (1) The patient’s age at the time of treatment initiation was > 16 years. (2) An intact set of diagnostic pre-treatment records available, including study models, panoramic radiographs, lateral cephalograms and intra- and extra-oral photograph series. The patients were divided into the following groups according to their OJ: Group J1 (OJ, 0-4mm), Group J2 (OJ, >4mm), Group J3 (OJ, <0mm).

Cephalometric analysis

All lateral cephalograms were traced using Dolphin imaging software.9, 10

Figure 1

Cephalometric landmarks and skeletal, dental, and soft tissue variables used in this study.

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Smile analysis

On frontal smiling photographs, nine smile variables (Figure 2) were measured by one investigator using the linear measuring distizer method in Adobe Photoshop at nearest 0.1mm. All smile variables were evaluated as a ratio except for tooth number and the upper midline (Table 1).

Figure 2

Smile measurements. A, Arc ratio; B, upper lip height; C, upper midline; D, buccal corridor ratio; E, smile index; F,archform index; G, lower teeth exposure; and H, interlabial gap.

https://s3-us-west-2.amazonaws.com/typeset-prod-media-server/8c5306b0-0761-4404-b2f4-9a074a05600bimage2.png
Table 1

Definitions of smile esthetic variables used in this study.

Arc ratio

Perpendicular distance of the incisal edge of tooth 11 (FDI) to a line connecting the cusp tips of the maxillary canine / distance between a tangent line of upper border of the lower lip and the maxillary intercanine line.

Tooth number

Number of the exposed teeth in the maxilla.

Upper lip height

The shortest distance from the incised edge of tooth 11 to the lower border of the upper lip / mesio-distal width of tooth 11.

Upper midline

Amount of deviation of the maxillary dental midline to the facial midline.

Buccal corridor ratio

Intercommissure width / intercanine gap

Smile index

Intercommissure width / interlabial gap

Archform index

Intercanine width / intermolar width

Lower tooth exposure

Distance from the incisal edge of tooth 11 to upper border of the lower lip / mesio–distal width of 41

Interlabial gap

Interlabial gap / intercanine width

Statistical analysis

Statistical analyses were performed using SPSS software (version 16.0; IBM Corp., Armonk, NY, USA). The normality of data was tested by Shapiro Wilk’s test and data was found to be skewed. Hence, to test the significance non- parametric tests were used. The significance of difference between the three study groups was tested by Krushkal Wallis tests followed by Mann- Whitney test for inter group comparisons. The level of significance and confidence intervals were 5% and 95% respectively.

Multiple linear regression analysis was performed to identify the cephalometric factors affecting smile measurements in different types of malocclusion.

Results

hows the comparison of the cephalometric variables in the study groups using kruskal- wallis test. The test revealed that SNA(0), SNB(0), ANB(0), SN-GoGn(0), FMA(0), L1-NB(mm), L1-NB(0), U1LI(0), U1PP(mm), IMPA(0), OJ, OB differed significantly among the groups whereas U1-NA(mm), U1-NA(0), UFH/LFH and PFH/AFH did not differ significantly among the groups. Table 3 shows the comparison of the smile variables in the study groups using Kruskal-Wallis test. The test revealed that the upper lip height, and inter-labial gap differed significantly among the groups, whereas arc ratio, tooth number, upper midline, buccal corridor, smile index, arch form index and lower tooth exposure did not significantly among the groups.

Table 2

Comparison ofcephalometric variables between different types of anterior overjet malocclusion using Kruskal Wallis test.

Variable

Group

N

Mean Rank

p-value

SNA(0)

1

30

50.07

2

30

57.62

3

30

28.82

Total

90

.000***

SNB(0)

1

30

40.07

2

30

24.52

3

30

71.22

Total

90

.000***

ANB(0)

1

30

30.58

2

30

75.40

3

30

30.52

Total

90

.000***

SN-GoGn(0)

1

30

49.33

2

30

57.35

3

30

29.82

Total

90

.000***

FMA(0)

1

30

51.73

2

30

52.15

3

30

32.62

Total

90

.000***

U1-NA(mm)

1

30

41.33

2

30

54.23

3

30

40.93

Total

90

.076NS

UI-NA(0)

1

30

39.03

2

30

51.70

3

30

45.77

Total

90

.170NS

LI-NB(mm)

1

30

50.13

2

30

50.72

3

30

35.65

Total

90

.038*

LI-NB(0)

1

30

54.48

2

30

50.12

3

30

31.90

Total

90

.002**

U1-L1(0)

1

30

39.58

2

30

32.50

3

30

64.42

Total

90

.000***

UI-PP(mm)

1

30

19.32

2

30

43.85

3

30

73.33

Total

90

.000***

IMPA(0)

1

30

57.33

2

30

54.78

3

30

24.38

Total

90

.000***

OJ

1

30

42.42

2

30

75.10

3

30

18.98

Total

90

.000***

1

30

47.48

2

30

63.65

3

30

25.37

Total

90

.000***
Table 3

Comparison ofsmile variables in the study groups using Kruskal Wallis test.

Variable

Group

N

Mean Rank

p-value

Arch Ratio

1

30

49.37

.178NS

2

30

38.28

3

30

48.85

Total

90

Tooth Number

1

30

40.42

.291NS

2

30

45.68

3

30

50.40

Total

90

Upper Lip Height

1

30

54.37

.000***

2

30

54.03

3

30

28.10

Total

90

Upper Midline

1

30

46.97

.100NS

2

30

49.98

3

30

39.55

Total

90

Buccal Corridor Ratio

1

30

47.93

.819NS

2

30

44.57

3

30

44.00

Total

90

Smile Index

1

30

39.97

.183 NS

2

30

52.22

3

30

44.32

Total

90

Archform Index

1

30

47.52

0.79NS

2

30

51.87

3

30

37.12

Total

90

Loweer Tooth Exposure

1

30

46.47

.832NS

2

30

46.78

3

30

43.25

Total

90

Interlabial Gap

1

30

54.53

.001**

2

30

51.12

3

30

30.85

Total

90

Table 4

Comparison ofcephalometric variables using Mann- Whitney for inter- group comparison

Variable

p-value

p-value

p-value

1 vs 2

1 vs 3

2 Vs 3

SNA(0)

.335NS

.003**

.000***

SNB(0)

.002**

.000***

.000***

ANB(0)

.000***

.961NS

.000***

SN-GoGn(0)

.137NS

.001***

.000***

FMA(0)

.744NS

.002**

.008**

U1-NA(mm)

.092NS

.858NS

.024*

UI-NA(0)

.070NS

.289NS

.347NS

L1-NB(mm)

.887NS

.027*

.028*

L1-NB(0)

.564NS

.001***

.009**

U1-L1(0)

.321NS

.000***

.000***

U1-PP(mm)

.000***

.000***

.000***

IMPA(0)

.594NS

.000***

.000***

OJ

.000***

.000***

.000***

OB

.007**

.000***

.000***

UFH/LFH

.433NS

.173NS

.018***

PFH/AFH

.988NS

.296NS

.181NS

(b): Comparison of smile variables using Mann- Whitney for inter- group comparison

Variable

p-value

p-value

p-value

1 vs 2

1 vs 3

2 vs 3

Arc ratio

.111NS

.900NS

.107NS

Tooth number

.435NS

.105NS

.492NS

Upper lip height

.912NS

.000***

.000***

Upper midline

.590NS

.107NS

.031*

Buccal corridor ratio

.673NS

.509NS

.994NS

Smile index

.042*

.673NS

.344NS

Archform index

.453NS

.100NS

.037*

Lower tooth exposure

.981NS

.671NS

.535NS

Inter-labial gap

.401NS

.001***

. .001***
Table 5

Cephalometric measurements correlated with Upper lip height in Group 1

Upper lip height

B

Standard error

p-value

SNA(0)

-0.82

0.22

.003**

SNB(0)

0.81

0.22

.003**

ANB(0)

0.83

0.24

.004**

FMA(0)

0.03

0.01

.043*

L1-NB(mm)

0.07

0.03

.016*

(b): Cephalometric measurements correlated with buccal corridor ratio in Group 1

Buccal corridor ratio

B

Standard error

p-value

PFH/AFH

-0.01

0.01

.040*

(c): Cephalometric measurements correlated with Archform index in Group 1

Archform index

B

Standard error

p-value

U1-L1(0)

0.01

0.00

.015*

(d): Cephalometric measurements correlated with Inter-labial gap in Group 1

Inter-labial gap

B

Standard error

p-value

SNA(0)

-0.17

0.08

.049*

ANB(0)

0.22

0.08

.021*

L1-NB(0)

-0.01

0.03

.012*
Table 6

Cephalometric measurements correlated with upper lip height in Group 2

Upper lip Height

B

Standard error

p-value

SNA(0)

0.36

0.12

.012*

SNB(0)

0.35

0.13

.017*

ANB(0)

-0.21

0.09

.039*

U1-L1(0)

-0.05

0.02

.015*

PFH/AFH

-0.03

0.01

.021*

(b): Cephalometric measurements correlated with upper midline in Group 2

Upper midline

B

Standard error

p-value

SNA(0)

0.01

0.03

.006**

SNB(0)

-0.10

0.03

.006**

PFH/AFH

-0.01

0.00

.023*

(c): Cephalometric measurements correlated with lower tooth exposure in Group 2

Lower tooth exposure

B

Standard error

p-value

SN-GoGn(0)

0.05

0.02

.013*

U1-NA(0)

0.08

0.03

.008**

U1-L1(0)

0.07

0.02

.005**

IMPA(0)

0.05

0.02

.014*

OB

-0.29

0.11

.018*

PFH/AFH

0.04

0.01

.011*
Table 7

Cephalometric measurements correlated with Arc ratio in Group 3

Arc ratio

B

Standard ratio

p-value

U1-PP (mm)

0.38

0.10

.002**

OJ

-0.15

0.07

.046*

(b): Cephalometric measurements correlated with upper midline in Group 3

Upper midline

B

Standard ratio

p-value

OB

0.11

0.04

.017*

(c): Cephalometric measurements correlated with buccal corridor ratio in group 3

Buccal corridor ratio

B

Standard ratio

p-value

U1-PP(mm)

-0.18

0.06

.012*

(d): Cephalometric measurements correlated with Archform index in Group 3

Archform index

B

Standard ratio

p-value

U1-L1(0)

0.01

0.01

.023*

(e). Cephalometric measurements correlated with Inter-labial gap in Group 3

Inter-labial gap

B

Standard ratio

p-value

U1-PP(mm)

-0.05

0.02

.034*

IMPA(0)

-0.01

0.00

.027*

Discussion

Our goal in this work was to quantify the association between aesthetic smile characteristics and various forms of anterior overjet (OJ) malocclusions, as well as to discover the cephalometric parameters affecting smile measurements in various types of anterior OJ malocclusions. The relationship between the maxillary and mandibular skeletons, the height and length of the upper lip, age, race, and gender are all factors that influence smile. 11 Smiles may be influenced by skeletal pattern, dental procumbency, or face form, according to Cheng and Cheng. 12

Because the posed smile is reproducible and can be generated on demand, it is frequently employed when analyzing face esthetics and smiling characteristics.13, 14, 15 As a result, smile characteristics were measured using frontal pictures of a posed smile. The use of a frontal facial image for analysis in this study had the benefit of being easy and inexpensive.

Subjective and objective evaluations of smile esthetics have always been used. Subjective assessment is a way of evaluating smiles that involves evaluators. Ordinal and interval scales are commonly used to examine esthetic preferences since they represent an ordered order of judgment from least to most desired.16, 17

Subjective evaluation has the disadvantage that aesthetic perception differs from person to person and is impacted by personal experiences and social settings. Many esthetic concepts about the face and smile are based on the opinions of authors rather than scientific evidence. Each smiling variable was defined as a ratio (a/b percent) that was utilized to reduce errors and boost reliability. 12

The cephalometric variables (Table 2) revealed that the sagittal skeletal relationship was significantly different in the study groups. The position of the maxilla was significantly different between Groups 1 and 3 and Groups 2 and 3. The maxilla was retrognathic in Group 3 (mean±SD= 79.9±2.0). The mandibular position differed significantly between Groups 1, 2, and 3 with Group 3 showing the maximum value of SNB(0). ANB(0) differed significantly between Groups 1 and 2 and also between Groups 2 and 3. The cephalometric measurements indicated that the patients in Group 2 had a skeletal Class II relationship and mandibular retrognathism as well as a high mandibular plane angle. The upper incisor measurements indicated that they were proclined but their position did not differ significantly among the groups. The lower incisors were also proclined and their position was significantly different between Groups 1 and 3 and Groups 2 and 3. The vertical position of the upper incisors differed significantly in all the groups. Group 3 showed the least overjet and overbite compared to the other groups.

The results of smile analysis (Table 3) results showed that different types of malocclusion prohibited different types of smiles. Regarding the malocclusion in Group 1, according to multiple linear regression analysis (Table 5 a-d), the upper lip height was significantly influenced by five of the cephalometric factors: SNA(0), SNB(0), ANB(0), FMA(0) and distance of the lower incisors from NB. The buccal corridor ratio was significantly influenced by the ratio of posterior face height to anterior face height while the archform index was significantly influenced by the inter-incisal angle. Inter-labial gap was significantly influenced by SNA(0), ANB(0) and L1-NB(0).

In Group 2 (Table 6 a-d), the upper lip height was positively correlated by SNA(0), SNB(0), ANB(0), inter-incisal angle and the ratio of posterior to anterior face height. Upper midline was significantly influenced by SNA(0), SNB(0) and the posterior to anterior face height ratio. The exposure of lower tooth was positively correlated by the mandibular plane angle, upper incisor position, inter-incisal angle, lower incisor angulation, overbite and ratio of posterior to anterior face height.

In Group 3, (Table 7 a-e), arc ratio was positively correlated with U1-PP (mm) and negatively correlated with overjet. The upper midline was positively correlated with overbite; Archform index was positively correlated with UI-L1(0). The inter-labial gap was negatively correlated with UI-PP(mm) and IMPA(0).

Smile analysis is a challenging and time-consuming task. However, photos cannot capture the dynamic quality of a smile. Furthermore, numerous aspects may be difficult to see in frontal smile images. On frontal smile images, the problem of an overly positive or negative OJ is less noticeable than in oblique and lateral smile photographs. Different views of smiling images may need to be examined in the future to ensure a complete smile.

Our findings revealed no direct link between overjet and smile characteristics. Cheng and Cheng 17, on the other hand, conducted a similar study in the Korean population and discovered that the horizontal disparity of anterior teeth (OJ) may be the most important factor determining smile style in various types of malocclusion. The disparities in results could be attributed to the two populations being researched, as well as differences in skeletal, dental, and smile variances between the two groups.

This study confirmed that the smile pattern varies between different types of malocclusion. Orthodontists must take into account the smile esthetics during diagnosis, treatment planning, and treatment mechanisms before orthodontic treatment. Further research is required to investigate smile features and advance the knowledge in this field.

Conclusions

The following conclusions were drawn from the study.

  1. In this study, some smile variables (upper lip height, inter-labial gap) differed significantly among different types of anterior overjet malocclusion.

  2. This study confirmed that the smile pattern varies between different types of malocclusion.

  3. In this study, we could not find a direct association between overjet and smile variables.

  4. Some of the smile characteristics were related to cephalometric measurements in different types of anterior OJ malocclusion.

Source of Funding

No financial support was received for the work within this manuscript.

Conflicts of Interest

There are no conflicts of interest.

References

1 

T Christou A Betlej N Aswad D Ogdon CH Kau Clinical effectiveness of orthodontic treatment on smile esthetics: a systematic reviewClin Cosmet Investig Dent2019118910110.2147/ccide.s189708

2 

T Moore KA Southard JS Casko F Qian TE Southard Buccal corridors and smile estheticsAm J Orthod Dentofacial Orthop 200512722081310.1016/j.ajodo.2003.11.027

3 

JL Ackerman MB Ackerman CM Brensinger JR Landis A morphometric analysis of the posed smileClin Orthod Res 19981121110.1111/ocr.1998.1.1.2

4 

DM Sarver The importance of incisor positioning in the esthetic smile: The smile arcAm J Orthod Dentofacial Orthop200112029811110.1067/mod.2001.114301

5 

V Krishnan ST Daniel D Lazar A Asok Characterization of posed smile by using visual analog scale, smile arc, buccal corridor measures, and modified smile indexAm J Orthod Dentofac Orthop200813345152310.1016/j.ajodo.2006.04.046

6 

L McNamara JA McNamara MB Ackerman T Baccetti Hard- and soft-tissue contributions to the esthetics of the posed smile in growing patients seeking orthodontic treatmentAm J Orthod Dentofac Orthop20081334491910.1016/j.ajodo.2006.05.042

7 

BJ Schabel L Franchi T Baccetti JA McNamara Subjective vs objective evaluations of smile estheticsAm J Orthod Dentofac Orthop 20091354S72910.1016/j.ajodo.2007.10.040

8 

R Islam T Kitahara L Naher A Hara A Nakasima Lip Morphological Changes in Orthodontic Treatment Class II division 1 Malocclusion and Normal Occlusion at Rest and on SmilingAngle Orthod20097925664

9 

CA Chang HW Fields FM Beck NC Springer AR Firestone S Rosenstiel Smile esthetics from patients’ perspectives for faces of varying attractivenessAm J Orthod Dentofacial Orthop 20111404e1718010.1016/j.ajodo.2011.03.022

10 

G Kanavakis L Krooks R Lähdesmäki P Pirttiniemi Influence of overjet and overbite on soft tissue profile in mature adults: A cross-sectional population studyAm J Orthod Dentofac Orthop 20191551576310.1016/j.ajodo.2018.02.015

11 

CM Campbell DT Millett A O'Callaghan A Marsh GT McIntyre M Cronin The effect of increased overjet on the magnitude and reproducibility of smiling in adult femalesEur J Orthod 2012345640510.1093/ejo/cjr077

12 

HC Cheng PC Cheng Factors affecting smile esthetics in adults with different types of anterior overjet malocclusionKorean J Orthod2017471318

13 

DC Havens JA McNamara LM Sigler T Baccetti The Role of the Posed Smile in Overall Facial EstheticsAngle Orthod2010802322810.2319/040409-194.1

14 

NC Springer C Chang HW Fields FM Beck AR Firestone S Rosenstiel Smile esthetics from the layperson’s perspectiveAm J Orthod Dentofac Orthop 20111391e91e10110.1016/j.ajodo.2010.06.019

15 

X Yu B Liu Y Pei T Xu Evaluation of facial attractiveness for patients with malocclusion A machine-learning technique employing ProcrustesAngle Orthod2014844106

16 

S Parrini G Rossini T Castroflorio A Fortini A Deregibus C Debernardi Laypeople's perceptions of frontal smile esthetics: A systematic reviewAm J Orthod Dentofac Orthop 201615057405010.1016/j.ajodo.2016.06.022

17 

G Janson NC Branco TMF Fernandes R Sathler D Garib JRP Lauris Influence of orthodontic treatment, midline position, buccal corridor and smile arc on smile attractivenessAngle Orthod20118111536110.2319/040710-195.1

Keywords

Categories:

Subject: Original Research Article

Keywords:

Keywords

Smile

Esthetics

Malocclusion

Soft tissue

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Received : 23-08-2020

Accepted : 10-10-2020


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