1. INTRODUCTION & BACKGROUND:

A smile is one of the most fundamental facial expressions for expressing feelings.^[1] An individual’s smile defines facial attractiveness, which is a valuable tool for influencing people.^[2] Smile is a dynamic position of the lips, which varies according to the degree of facial muscle contraction and the lip profile.^[3] The smile is an essential component of face aesthetics. As a result, to obtain a beautiful and youthful smile, many dentists incorporate face aesthetics into their treatment plans.^[4]

The teeth define smile aesthetics, which are framed by the lips, the contour of the gums, and the number of gaps and voids. The extent of gingiva exposure when smiling, the arc of the smile, the proportions of the teeth, the presence of a midline shift and changes in axial inclination, buccal corridors, gingival height and contours, the presence of a diastema, and the colour of the teeth all contribute to the harmony and symmetry of an aesthetic smile.^[5]

Poor dental aesthetics have been associated with low self-esteem and are regarded to be socially, intellectually, and professionally detrimental.^[6] Younger generations place a growing emphasis on all elements of their appearance, and the importance of a beautiful smile is very clearly seen.^[7] Women are more concerned with their appearance than males, and female patients have been observed to be more concerned with their dental appearance and to be more critical when grading smile aesthetics than male patients.^[8,9]

The evaluation of facial attractiveness is subjective, based on artistic sensibilities. It is widely accepted that views of facial beauty are multidimensional, with genetic, environmental, and cultural underpinnings. ^[10,11] The perception of a smile may differ between laypeople, dentists, and specialty professionals. Various studies have been done before but yet restricted to the outdated methods of conventional smile analysis and focused more on the measurement parameters rather than the actual perception of the individual. The use of photographic analysis tends to be a more accurate method than impression-making and other digital software methods to analyze the smile of an individual.

          It is important to know the opinions and perceptions of a variety of dental specialty individuals for considering a smile attractive might be different. It is not necessary that the opinions of lay person may coincide with the dental professionals every single time. Every specialty has its way of analyzing the aesthetics of individuals and providing a suitable treatment option for them. Hence, this study aims to evaluate, compare and correlate the perceptions of smile aesthetics among dental professionals and lay individuals using a photographic analysis and questionnaire method.

2. NEED FOR THE STUDY:

Aesthetic perception varies from person to person and is influenced by their personal experience and social environment. For this reason, professional opinions regarding the evaluation of facial aesthetics may not coincide with the perceptions and expectations of patients or laypeople. Lay persons are less critical than general dentists and dental specialists regarding the aesthetics in photographs of the dentition. Therefore, this study is designed to evaluate and compare the perceptions of laypeople, normal dentists, and dental specialists about smile aesthetics, factors affecting a smile, and the attractiveness of a smile.

3. RESEARCH QUESTION:

To assess the differences in how the general public, dentists, and dental specialists from various specializations view and percept the aesthetics of a smile.

a.    AIM:

To evaluate and compare the perception of smile aesthetics among dental professionals and lay individuals using a photographic analysis and questionnaire method.

b.    OBJECTIVES:

To assess the smile perception of a lay individual.

To assess the perception of dental specialty professionals regarding smile aesthetics.

To compare the perception of dental specialty professionals (Prosthodontists, endodontists, orthodontists, periodontists, and normal dentists) about smile aesthetics.

To evaluate and compare the dental and facial aesthetics of a smile and rate them according to a visual analogue scale(VAS).

4. REVIEW OF LITERATURE (Please follow Vancouver style of referencing and in-text citation):

Duggal et al^[12]:

Armalaite et al ^[5]:

The purpose of this study was to evaluate how smile characteristics are perceived by dental students. The study was performed in 431 local and international dental students at the Lithuanian University of Health Sciences. The study data were collected using a three-part questionnaire. The first part of the questionnaire included sociodemographic items, i.e., student gender, age, nationality, and years of study; the second consisted of questions about facial aesthetic features; and the third elicited responses to photographs of 17 different smiles were  retrieved. The smile aesthetics were evaluated according to their dentolabial, dentogingival, dental, and dental arch characteristics using a 5-point numeric rating scale. Women were more critical than men when evaluating gingival smiles, the ‘golden proportion’, occlusal cant, and dental crowding. The most unfavourable smile characteristics were identified in the dental analysis category, with hypodontia ranked as the worst smile feature. The study concluded that Among dental students, the most distracting characteristics of a smile when determining its attractiveness were hypodontia, gingival smile, a reversed curvature of the occlusal plane, and dental crowding.

Flores-mir et al ^[13]:The objective was to compare the aesthetic perception of different anterior visible occlusions in different facial and dental views (frontal view, lower facial third view and dental view) by laypersons. The different views were rated by 91 randomly selected adult lay persons. Visual Analogue Scale (VAS) ratings of aesthetic perception of the views. Anterior visible occlusion, photographed subject and view had a significant effect on the aesthetic ratings. Also, gender and the interaction between gender and level of education (p50.046) had a significant effect on the aesthetic rating. It was concluded that a lay panel perceived that the aesthetic impact of the visible anterior occlusion was greater in a dental view compared with a full facial view. The anterior visible occlusion, photographed subject, and view type are factors, which influence the aesthetic perception of smiles.

A study by Ousehal et al ^[3]: aims to evaluate and compare the impact of altered smile characteristics on the perception of smile esthetics between Moroccan dentists and laypeople. Thirty-four digital smile photographs displaying alterations in crown length and width, lateral incisor gingival margin position, gingival exposition, midline diastema, and upper midline deviation were presented to a sample of 30 dentists and 30 laypeople. The ratings were assessed with a visual analogue scale. Compared to that of laypeople, Moroccan dentists’ evaluation of the gingival smile was more critical when the decrease in central incisor crown length was 2.5 mm or greater and when the increase in the gingival exposition was 4 mm or greater (p< 0.01). Moroccan dentists were also critical in their evaluation of maxillary lateral incisor crown width alterations and incisal midline deviations. It was concluded that Moroccan dentists evaluate smile aesthetic alterations more critically than Moroccan laypeople.

5. METHODOLOGY:

a.    STUDY DETAILS:

                                              i.          STUDY DESIGN:

Cross-sectional study design.

                                            ii.          STUDY SITE: Department of Prosthodontics, Crown and Bridge, Yenepoya Dental College, Mangalore.

                                          iii.          FUNDING DETAILS: Self-funded

                                          iv.          STUDY DURATION: 6 months.

b.    PARTICIPANT DETAILS:

                                              i.          SOURCE OF DATA:

·       Out-patient department of Yenepoya Dental College, Mangalore.

·       After selecting the participants, they will be informed about the study details in the language they understand. (Annexure I)

·       Participants will be asked to sign the consent letter of participation. (Annexure 4).       

                                            ii.          SAMPLE SIZE:

Based on the literature, Duggal et al (2022), it is found that the proportion related to attractive and unattractive smiles is nearly equal to 0.6:0.4

so, the following sample size is suggested

n= z^2p(1-p) / E² = 1.96²(0.6)(0.4)/(0.13)² = 55

55 participants will be included in the study.

                                          iii.          METHOD OF SAMPLING (SAMPLING TECHNIQUE):

Convenience sampling method.

                                          iv.          RANDOMIZATION AND BLINDING (IF ANY):

Double-blind study.

                                             v.          INCLUSION CRITERIA:

Female individuals belonging to the age group between 18 to 25 years.

Female individuals with permanent dentition.

                                          vi.          EXCLUSION CRITERIA

Individuals with prosthetic restorations in anterior teeth.

Individuals with completed or ongoing orthodontic treatment.

Dental professionals.

Individuals with missing teeth.

Individuals who have undergone cosmetic procedures like bleaching of teeth.

Individuals with facial asymmetry and craniofacial abnormalities.

                                        vii.          WITHDRAWAL CRITERIA

Participants have the right to withdraw from the study at any time.

                                      viii.          DISCONTINUATION CRITERIA

Participants having any kind of identity issues with their photographs, or not willing to fill out the questionnaire form, may be included in the discontinuation criteria.

c.     STUDY TOOL:

Questionnaire forms.

Dynamic and static photographic records

                                              i.          DESCRIPTION (QUESTIONNAIRE; INTERVIEW SCHEDULE; SCALES; SCORES; DATA COLLECTION FORM; PROFORMA; ETC)

Questionnaire form, visual analogue scale, data collection form.

d.    METHOD:

                                              i.          DETAILS OF THE METHODOLOGY INCLUDING DETAILS OF SAMPLE COLLECTION:

A.   Materials and Armamentarium

Armamentarium:

a)    DSLR camera

b)   Photo editing software (Adobe Photoshop)

c)    Laptop

d)   Questionnaire form

Methodology:

Participants will be recruited from the outpatient department of Yenepoya Dental College. An informed consent sheet and participant information sheet will be provided and the study procedure will be explained to them prior.

Photographic data records:

Photographic data will be recorded for each participant in a standardized manner. A DSLR Camera will be used for recording the static and dynamic records of the participants. A single operator will be recording the data for each participant.

Static photographic record:

A frontal and lateral view of each participant will be made by the operator. The participant is informed to be seated and be at rest for this record. Another record of a posed smile is made by the operator, when participants are asked to pose a smile by saying the word “cheese” to record a complete smile. All the records will be stored digitally and edited using a picture editing software (preferably Adobe Photoshop) for the standardized measurements.

Standardization of records:

1.    A white background will be used.

2.    All the records are to be made in in-office light conditions.

3.    The camera will be held at a distance of 4 feet from the participant.

4.    Each participant will be asked to look straight at the camera sight held by the operator.

5.    The participant will be asked to keep his head straight such that Frankfurt’s horizontal plane is parallel to the floor.

Dynamic record:

A dynamic record is obtained by recording a 5-second video of each participant when they are instructed to pose a smile from the rest position. The dynamic records will be recorded in the same conditions as those of static records.

Two different questionnaire forms will be formulated:

Participant Questionnaire:

Participants will receive the form which has two parts, the first part consists of demographic data which includes:

a)    Name

b)    Age

c)    Occupation

d)    Address

e)    email

f)     Education

The second part consists of questions to analyze their perception regarding their smile, to evaluate how they rate their smile (on VAS) and whether they are satisfied with the existing smile or not.

Every investigator will inspect the static and dynamic records of each participant, and give their perception of smile aesthetics for every participant through an investigator questionnaire form.

Investigator questionnaire:

Each investigator will receive the investigator questionnaire form which consists of two parts, the first part includes demographic data:

a)    Name

b)    Age

c)    Gender

d)    The speciality which they belong to

e)    Years of experience

The second part will include the pictorial data and questions regarding the smile aesthetics of each participant including:

a)    Type of smile line, lip line

b)    Type of smile

c)    Amount of gingival display

d)    Position of gingival zenith

e)    Position of gingival line

f)     Amount of tooth visibility

g)    Midline shift

h)    Tooth ratio (golden proportion, golden rectangle)

i)      Tooth texture

j)      Tooth shade and its progression

k)    Tooth form

l)      Correlation of Extraoral measurements.

Also, the aesthetic score of the smile for each participant is to be given by each investigator based on a Visual Analogue scale (VAS).

All the readings obtained from both the participants and investigator questionnaires will be stored efficiently in a data collection sheet (Microsoft Excel) for further statistical analysis.

                                            ii.          DETAILS OF ANALYSIS: (Including statistical tests)

Between-group mean val­ue differences will be calculated using the t-test with the signifi­cance level set at a P-value of 0.05.

Analysis of variance (ANO­VA), Tukey’s studentised range test, and Pearson correlation analysis were performed for the statistical analysis of differences and correlations between the participant’s self-smile-evaluation scores and the Investigator smile analysis scores.