Influence of Lip Height and Inciso Gingival Height in Relation to Smile Aesthetics in Orthodontically Treated IndividualsType of manuscript: ResearchRunning Title: Smile Aesthetics in OrthodonticsNurul Afiqah Amani Binti ZaabaUndergraduate studentSaveetha Dental College, Saveetha University, Chennai, India.Dr. Saravanna PandianDepartment of OrthodonticsSaveetha Dental College, Saveetha University, Chennai, India.Corresponding AuthorDr. Saravanna PandianDepartment of OrthodonticsSaveetha Dental College Saveetha University162, Poonamalle High Road Chennai 600077Tamil Nadu, India.E-mail: Telephone number:Total number of words: 2517Abstract Aim: To study on the influence of lip height and inciso gingival height in relation to smile aesthetics in orthodontically treated individuals.Materials and method: The study was conducted in Saveetha Dental College, Chennai. The participants were informed and their consent were obtained for this study, in order to displayed and used their image in the study. The participants were previously having orthodontic treatment in relation to smile aesthetics and free from any other smile aesthetics treatment. Total of 30 participants photographed were used in this study for assessment of their smile. A total of 10 general practitioners,10 orthodontists and 10 lay people were asked to be the evaluators panel. The smile of each participants were then analysed by using visual analogue scale (VAS) and scored for each categories in the questionnaire. Data were then collected and analysed.Results: The study was compromised of 30 dental students of post graduates and undergraduates with age range from 19 to 26 years old. The mean age of the evaluators was 20.07. It shown that 40.7%, 27.3%, 20.0% and 12.0% of the subjects had good, fair, very good and excellent smiles respectively after undergone orthodontics treatment. There were no definite difference on the frequency distribution of the smiles. According to the data of the comparison of the inciso gingival height in social smile and spontaneous smile of the study models, Chi-square test shown no significant differences between the two types of smile according to the visibility of the maxillary central incisors. The frequency distribution of the upper lip height also shown the same. In addition to this, 73% of the evaluators chose social smile as the most attractive smile in general, followed by spontaneous smile (17%) and commissure smile (10%).Conclusion: Both social and spontaneous smile may exhibits difference variance, but it is not too significant. Thus this study prove that the upper lip height and inciso gingival height have no effect on rating of smiles in social as well as spontaneous smile of the orthodontically treated people. Introduction In this era of modernity, facial aesthetics is very important to most of the people, as it act as indicator of increased in the social values of an individual in the society. Facial aesthetics not only involve eye, nose and lips, but it also involve all part of the facial structures. Among them smile is an important area which outweigh the other structures, as smile ranks second after the eyes in the term of attractiveness. This was stated and proven by Goldstein 1. Literally, smile can be described as the facial expressions which enhance facial attractiveness on an individual 2. Therefore, smile is always used as a form of communication in the society as it also help to increase self esteem. Based on gender, upon smiling female individuals usually having softer appearance and more facial animation compare to male 3. Thus, female appear more attractive than male when they are smiling. However, each individual may have their own unique forms of smile which can be assessed and evaluated. In certain circumstances, there might be few problems arising like gingival display, midline diastema 4, teeth alignment, colour of teeth and many more, which require dentist counselling and treatment. Most of these, commonly related with orthodontic treatment as it help to improve facial aesthetics, especially smile. In addition, self satisfaction and psychosocial behaviour also give influence toward the smile aesthetics 5, and this will become one of their concern.  There are lots of factor which influence smile aesthetics. Examples are smile style, smile index, golden proportion, smile arc, inciso-gingival height, width of buccal corridor 6,7,, ratio and symmetry of maxillary central incisors, lip volume, gingival design and etc 8. These factors are usually taken in consideration when orthodontists analysing and planning for smile aesthetics. This is because these factors will help for better approach in orthodontic treatment and also able to meet the expectations as well as patient’s desire in seeking for better smile aesthetics. Thus, complete and thorough observation need to be done in providing better treatment for the patients. Therefore, this study is focusing more on lip height as well as inciso gingival height in relation to smile aesthetics.  Next, there are two types of smile which are commonly known, they are social smile and enjoyment smile 9,10. Social smile is also known as cupid smile 8 or posed smile , whereas enjoyment smile is known as Duchenne smile 9 and spontaneous smile. Social smile is voluntary and unstrained facial expression, which characterised by moderate contraction of elevator muscles of lip, while enjoyment smile occur due to maximal contraction of the upper lips elevator and lower lips depressor which is involuntary 10. Other form of smile is called as commisure smile or Mona Lisa smile. It is usually used when greeting people in public or in unusual occasion or situation 8. These three types of smile are commonly seen in each individual, but being used in different environment. Based on these form of smile, complex smile (enjoyment smile) is the most suitable type of smile to be used for evaluating the smile aesthetics 11. In general, smile aesthetics or beauty evaluation of an individual is very subjective which is difficult to be analysed and compared between each person. However, with adequate and deep knowledge on the smile aesthetics, it will help to provide a better evaluation and able to improve the aesthetic features as well as self satisfaction of an individual. Thorough study and treatment planning also will help to enhance better outcomes of the treatment. Therefore, this study is conduct to know the influence of lip height and inciso gingival height in relation to smile aesthetics in orthodontically treated individuals.Materials and Method The study was conducted in Saveetha Dental College, Chennai, India. A total of five participants with the mean age of 22 were involved in this study. The participants were informed and their consent were obtained for this study, in order to displayed and used their image in the study. Their smile aesthetics were then assessed by a total of 30 dental students, which compromised of 8 post graduates students and 22 undergraduates students. The smile of each participants were then analysed  by using visual analogue scale (VAS), as  it is the most common measuring tool for assessment of dento-facial aesthetics 12.The sample size of this study was determined by using G Power analysis based upon a study conducted by Charan J 13. According to this method, the sample size for this study was calculated to be 30, by using formula mention as below.Sample size: Z 1? ? /2p2 p( 1 ? p )                                                d2According to this formula 13:Z 1? ? /2p2  is a standard normal variate.P value is based on proportion of studies model based on previous studies and the value was 0.98d is absolute error or precision and it is 0.05Therefore,           Sample size: 1.962X 0.98(1-0.98).  = 30                                            0.052The inclusions and exclusions  criteria which be taken in consideration when selecting the participants were listed as follow:Inclusion criteriaPleasing facesPermanent dentition with normal occlusion No obvious facial asymmetryNo abnormalities in oral cavity and facial regionThe participants previously undergone orthodontic treatment Free from any other smile aesthetics treatment. Exclusion criteriaDeciduous dentition or mixed dentitionObvious facial asymmetryAbnormalities in oral cavity and facial regionDo not undergo orthodontic treatment previouslyUndergo other smile aesthetics treatment1.1 Preparation of Smile PicturesThe study participants consisted of 6 patients, whom having orthodontic treatment previously. The frontal view of each participants will be taken in a standing and normal head position, by using digital camera. The participants were asked to show three different types of smile; (1) commissure smile, (2) social smile and also (3) spontaneous smile, when their photographed were taken. Each photographed were edited by cropping the picture in order to illustrates only the lower third of the face, particularly smile, as the result should not be affected by other area of the faces. Selected photographed were then printed in colour manner for the evaluation and assessment.(1) commissure smile.                             (2) social smile                     (3) spontaneous smile1.2 Assessment of SmileTo determine the influence of lip height and inciso gingival height in relation to smile aesthetics in orthodontically treated individuals, a survey was done which involve post graduates students as well as undergraduate students as  the evaluating panels. Their age also were recorded, in order to understand their different perceptions regarding smile aesthetics.  The evaluators were provide with a questionnaire and instructions regarding this study, before they evaluating patients smile aesthetics. Rating will be given be given based on facial smile particularly, not involve with other facial structures. The booklet of the questionnaire was included with a 100 point scales, with 1-20 as poor, 21-40 as fair, 41-60 as good, 61-80 to be very good and 81-100 as excellent for the rate of facial smile attractiveness. The score were tabulated and analysed.  The inciso gingival height was assessed based on the length of maxillary incisors, from the incisal tips to cervical area approaching the gingival margin. It was scored based on the visibility of maxillary incisors (score of 1-completely visible, score of 2-75%-100% visibility, score of 3- less than 75% visibility). This will then be take account in relation to smile arc. Next, for the upper lip height, it is evaluated by measuring the length of clinical crown of upper central incisors in relation to the height of the upper lips. Each smile were assessed and mean rated scores were calculated.This was measured based on 5 scores as follows (estimation) 14:Score of -2: Height of upper lip was positioned in two thirds of clinical crown of the upper central incisors superior to gingival margin.Score of -1: Height of upper lip was positioned in one third of clinical crown of the upper central incisors superior to gingival margin.Score of 0: Height of upper lip was positioned as the same level as gingival margin of the upper central incisors.Score of 1:Height of upper lip was positioned in a third between the clinical crown of the upper central incisors and gingival margin.Score of 2: Height of upper lip was positioned in two thirds between the clinical crown of the upper central incisors and gingival margin.1.3 Statistic analysisAll the data were recorded and tabulated for analyzation by using Microsoft excel. The Chi-square test was used to to compare the data and checked for the data distributions.  ANOVA was also used to compare the smile aesthetics and differences between two types of smile of the subjects, which are social and spontaneous smile. ResultsTable 1: Overall Rate of Smile Attractiveness Based on Commissure, Social and Spontaneous SmileP = 1.0 Chi-square test Table 2: Comparison of the inciso gingival height in social smile and spontaneous smile.P = 0.79 Chi-square test Table 3: Comparison of the upper lip height in social smile and spontaneous smileP = 0.79 Chi-square test                                            Pie chart 1: Attractivenes types of smile The study was compromised of 30 dental students of post graduates and undergraduates with age range from 19 to 26 years old. The mean age of the evaluators was 20.07. Based on Table 1, it shown that 40.7%, 27.3%, 20.0% and 12.0% of the subjects had good, fair, very good and excellent smiles respectively after undergone orthodontics treatment. There were no definite difference on the frequency distribution of the smiles. Next, Table 2 demonstrated the comparison of the inciso gingival height in social smile and spontaneous smile of the study models. According to the data above and Chi-square test there were no significant differences between the two types of smile according to the visibility of the maxillary central incisors. In Table 3, it also shown similar results as in Table 2 based on their frequency distribution of the upper lip height. In addition to this, based on pie chart 1, it shown that 73% of the evaluators chose social smile as the most attractive smile in general, followed by spontaneous smile (17%) and commissure smile (10%).Discussion  Physical appearance and personality is very important for each individual, and they are the most common things that usually seen and take account by other people. First impression of people usually will describe what kind of personality that the individuals have. Physical appearance is relatively face, which include mouth and teeth, and they are taken in consideration in facial aesthetics 15. Thus, the harmony of physical appearance and smile particularly will help to enhance self esteem of an individual. therefore, most of the people seek the orthodontists help to improve their smile aesthetics. In this study, it demonstrated in smile attractiveness after the orthodontic treatment. Most of the participants in this study satisfied with their smile.  In this study, photographed that used for evaluation is limited to their lower face particularly the mouth area. This was done in order to prevent any factors which may influence score given by the evaluators. This research was focusing on these aspects of smile aesthetics: smile attractiveness, inciso-gingival height and also height of the upper lips. Based on these variables the smile attractiveness were rated by the evaluators. It is done by using visual analogue scale (VAS), as it provide productive results on the smile scoring. The used and results of VAS in the study was also supported by Ioi Hideki in providing simple, rapid, and reproducible results 16.  Thus, the data collected by using this scale can be accepted in general. Next, in this study it also focusing more on two types of smile which were social and spontaneous smile. Both of these smile were the one that commonly used by people. However, when evaluating the overall smile attractiveness, commissure smile also was included. Based on the results of the study, it showed that most of the participants had good smile in average. The smile of the participants may have improve after the orthodontic treatment. In Jahanbin A et al. study, it stated that there were no significant difference between the normal occlusion and orthodontically treated people 14. However, in a study reported by Ke Zhang, there were improvement on smile aesthetics regardless the initial severity of malocclusion 17. Thus, in order to know improvement of smile, the smile aesthetics of the participants should be evaluated before and after the orthodontic treatment, in order to ensure that the results were authentic.  In addition, in this study it demonstrated that the mean and standard deviation of inciso gingival height between social smile and spontaneous smile had no significant in frequency distribution. It was determined by measuring the visibility of the clinical crowns of maxillary central incisors. The visibility of maxillary central incisors was much prominent in spontaneous smile when compared to social smile. Similar results also seen in comparison of the upper lip height in social smile and spontaneous smile. Based on this factor, the upper lip height in social smile show minimal gingival display, whereas majority of spontaneous smile the upper lip is located in positioned as the same level as gingival margin of the upper central incisors. Based on these two factors, it showed that the visibility of gingiva and crown of maxillary central incisors will affect the smile aesthetics of the patients. Minimal gingival display and exposure on the height of the maxillary central incisors is considered more attractive during smile. In an article reported by Chaves E, he strongly agreed upon minimal gingival display, there will be increased in smile aesthetics18. This was also agreed by Kokich that displaying the teeth along with some gingiva were perceived as more aesthetics 19. Similar results also reported in Hulsey’s study, where when the upper lip is located in positioned as the same level as gingival margin of the upper central incisors, they considered it as most attractive 20. However,  Jahanbin A study show different result from this as the height of upper lip has no effect when scoring the smile.  In addition to this, increasing in age will also decreased the maxillary lip line height and tooth displaying association with increased in upper lip length 21, which may affect the smile aesthetics. However, in this study the mean age of the participants was 22 and they were mostly young adults. Thus, there will be no variance regarding the age and this factor was not taken into considerations in this study.  On top of that, when planning for smile aesthetics for particular individuals not only visibility of gingiva and crown of maxillary central incisors as wells upper lip height were observed. Other factors also need to be evaluated like malocclusion, smile arc, buccal corridor, teeth alignment, colour of teeth and also anatomical of tooth especially the anterior teeth. These factors will be the parameters and taken into considerations for directed and effective treatment approach by the orthodontists, for better treatment planning. This also need to be done in order to meet patient expectations as well as to enhance the aesthetics values of their smile. Conclusions Nowadays, the orthodontic treatments have been increasing frequently in relation to improvement of smile aesthetics and also enhancement of the basic functions. Therefore, evaluation of visibility of the clinical crowns of maxillary central incisors as well as the upper lip height is important for determined the aesthetics quality of smile. Although there were no significant difference when comparing the social and spontaneous smile, both type of smile exhibits difference variance. Thus this study prove that the upper lip height and inciso gingival height have no effect on rating of smiles in social as well as spontaneous smile of the orthodontically treated people. References 1 Goldstein RE. Study of need for esthetics in dentistry. J Prosthet Dent. 1969;21:589-598.2 Hsin-Chung Cheng, Pei-Chin Cheng. Factors affecting smile esthetics in adults with different types of anterior overjet malocclusion. Korean Journal of Orthodontics. 2017;47(1):31-38.3  Farhana Ghaffar, Mubassar Fida. Effect of extraction of first four premolar on smile aesthetics. European Journal of Orthodontics. 2011;33:679-683. 4 Sridarhan S, Samantha C. Comparison of perception of smile by orthodontist and other specialty dentists: A questionnaire study. International Journal of Orthodontic Rehabilitation. 2016;7:92-6.5 Harrita. S, Dhanraj. The impact of dental aesthetics on the psycho-social behaviour and self confidence in university students in Chennai. Int J Pharm. 2017;43(1):29-31.  (SAV)6 Farzanegan F, Jahanbin A, Darvishpour H, Salari S. Which has greater influence on smile esthetics perception: Teeth or lips?. Iranian Journal of Otorhinolarngology.2013;25(73):239-244.7 Anthony L, Magazine, Sarah B. Schroetter, Kathy Freeman. Improvement in smile esthetics following orthodontic treatment A restropective study utilising standardised smile analysis. Angle Orthodontist. 2014;84(3):492-499.8 Machado AW. 10 commandments of smile esthetics. Dental Presss  Orthod. 2014;19(4):136-157.9 Amjad Al Taki, Thar Hayder Mohammed, Ahmad Mohammad Hamdan. Influence of the smile line on smile attractiveness in short and long face individuals. International Journal of Dentistry. 2017:1-7.10 Suchita Madhukar Tarvade (Daokar), Gauri Agrawal. Smile analysis: A review part I. Int J Contemp Dent Med Rev. 2015:1-411 Carlox Alexandre Camara. Aesthetics in orthodontics: six horizontal smile lines. Dental Press J Orthod. 2010;15(1):118-131.12 Janghu D, Dua VS, Mangla R, Khanna M. Smile esthetics. Indian J Oral Sci. 2015;6:101-107.13 Charan J, Biswas T. How to calculate sample size for different study designs in medical research?. Indian Journal of Psychological Medicine. 2013 Apr; 35(2): 121.14 Jahanabin A, Pezeshkirad H. The effects of upper lip height on smile esthetics perception in normal occlusion and non extraction, orthodontically treated females. Indian J Dent Res. 2018;19:204-207.15 Prasad V, Tandon P, Sharma VP, Singh GK, Maurya RP, Chugh V. Photographical evaluation of smile aesthetics after extraction orthodontic treatment. J Orthod Res. 2015;3(1):49-56.16 Ioi H, Nakata S, Counts AL. Influence of gingival display on smile aesthetics in Japanese. The European Journal of Orthodontics. 2010 Apr 19;32(6):633-7.17 Ke Zhang, Lan Huang, Lin Yang, Li Xu, Chaoran Xue, Zichao Xiang, Mengyuan Zhao, Song Li, Yuxing Bai and Ding Bai. Effects of transverse relationship between maxillary arch, mouth and face on smile aesthetics. The Angle Orthodontist. 2016 Apr 29;86(1):135-141.18 Chaves S, Rodriguez J, Peres MF, and Cunningham G. Improving smile and dental esthetics: A online comprehensive periodontal and restorative approach after orthodontics. Our J Gen Dent. 2014;3:170-173. Available from: http://www.ejgd.org/text.asp?2014/3/2/170/13485619 Kokich V, Kiyak H, Shapiro P. Comparing the perceptions of dentists and lay people to altered dental esthetics. Journal of Esthetics Dentistry. 1999;11:311-324.20 Hulsey CM. An aesthetic evolution of lip-teeth relationship presents in smile. Am J Orthod. 1970;57:132-144.21 Pieter Van der Geld, Paul Oosterveld, Anne Marie Kuijpers-Jagtman; Age-related changes of the dental aesthetic zone at rest and during spontaneous smiling and speech, European Journal of Orthodontics. 2008;30(4):366–373,