Evaluation of Facial Esthetics using Golden Proportion Values in Dravidian Population for Different Classes of Malocclusions

Improvement in esthetic appearance and functional occlusion are the pillars of contemporary orthodontic procedures. The aim of this study was to assess variations in facial proportions between skeletal classes I, II, III populations in order to establish objective departures from Golden Proportion norms. The study sample was divided into three groups based on the skeletal malocclusion, namely skeletal class I, class II and class III groups. Various markers were identi ied in these photographs in order to de ine facial symmetry and balance with the ideal values. Golden Proportion values were compared with that of the obtained results, and these values were checked for skeletal class I, II, III malocclusions. Our study showed a signi icant difference between skeletal class II and III malocclusions when correlated with Golden Proportion values. Skeletal Class I malocclusions showed a greater correlation with golden proportion values. Golden proportion ratios aremore valid in cases of skeletal class I malocclusions. Hence, the objective of treating class II and class III malocclusions should be more focused on attaining values closer to the desired ratio for optimal facial balance and symmetry.


INTRODUCTION
The demand for elective procedures solely for improving esthetics is ever-growing. Orthodontists must have an objective outlook in assessing facial features which are regarded as esthetic and in harmony with the surrounding structures (Young and Smith, 1993). One of the main requirements for better esthetics is the balance between the proportions between the various structures of the face. Many linear and angular measures of soft tissue pro ile and different cephalometric analysis have been developed to determine ideal proportions (Ayub et al., 2019). Improvement in facial esthetics is carried out using orthodontic or a combination of orthodontic and surgical procedures (Naini et al., 2006). Most people request for improvement in facial esthetics and this percentage has only risen more rapidly over the past decade (Zachrisson, 2015). Maintaining appropriate facial height, width and symmetry are essential to ensure a harmonious balance between the muscles and soft tissues (Rossetti et al., 2013). This esthetic opinion is in luenced by multiple factors such as social outlook, cultural balance, ethnicity and age (Villegas et al., 2015). Ensuring a harmonious outlook is dependent on the balance between proportions and symmetry. Ideal values are connected to these proportions and are explained by a ratio 1:1.618 (Lecocq and Trung, 2014). Texts on divine proportion existed since the times of Phidias and were technically and scienti ically explained by Filus Bonacci who assigned a numerical value to it (Maharjan and Joshi, 2018). These proportions are more important with respect to dentists in maintaining proportions of the face (Pini et al., 2012). This particularly applies to orthodontic correction, given that the objectives required at the end of treatment include esthetic harmony along with functional stability (Saifuddeen and Masran, 2017). The aim of our study was to compare the facial proportions between the three different sagittal skeletal patterns and to estimate the deviation of these values from that of the golden proportions.

MATERIALS AND METHODS
The sample consists of frontal photographs of 60 individuals. The sample was divided into three groups of 20 based on their skeletal classi ication as skeletal class I, II & III. The facial photographs were obtained in natural head position (NHP) with 1.2mm maintained in all patients. All measurements were done after appropriate calibration. 10 photographs were selected and reassessed by the same author after 2 weeks to verify the reproducibility. The following two ratios were checked to see if they followed divine proportions among the three skeletal patterns.
(a) The ratio of the width of face to the height of the face is supposed to be 1: 1.618.
(b) The ratio of Sto-Me: Me-Lc is supposed to be 1:1.618.

Statistical Analysis
Statistical tests were performed using SPSS software Ver 20.0 (SPSS Inc, Chicago). Oneway ANOVA and post Hoc Tukey's HSD test for multiple comparisons was applied. The signi icance level was set at 0.05.

RESULTS AND DISCUSSION
The Kappa coef icient ranged from 0.715 to 0.9, which rated the reliability of the test results to be from good in agreement. In Table 1, ANOVA test of variance was used to determine variations in the ratio between width to height of face in three skeletal malocclusions. Skeletal class I and III groups showed signi icant differences. But signi icant variations in Golden Proportion values were seen in Skeletal class II and III groups.
In Table 2, ANOVA test of variance was used to determine variations in the ratio between Sto-Me: Sto-LC in three skeletal malocclusions. Skeletal class I and III groups were statistically signi icant. Skeletal class II and III groups were also statistically signi icant. Variations from Golden Proportion Values were seen in Class II and Class III groups. Differences in values from Golden Proportion Values were seen in Class II and Class III groups. It is not consistently seen in most features of Class II, III patients in Dravidian Population.
Segregation of the face into one-thirds and ifths is a routine photogrammetric method for analyzing symmetry. In our study, all measures analyzed were uniform in the group selected, and we selected measurements that could be reproduced by different operators. Several 'neonatal' characteristics, such as the relatively large forehead and a rounded and smaller face in general, stated that 'babyness' is the characteristic that separates them from the normal group. Considering most parameters of the face, more correlated phases had a smaller face (Felicita, 2017). Gesch applied ideal proportions practically for improving facial esthetics (Gesch et al., 2006). He stressed upon treating the dentition and the face based on the divine proportion. The lower 1/3 rd of the face predominantly in luences facial appearance. The fullness of the lips and the importance of a pleasing smile are key factors in in luencing general opinion. Vitruvian thirds in the lower face have to be modi ied to a 30% upper lip, 70% lower lip-chin projection (Naini et al., 2006). In the present study, positive groups (Class I) showed good harmony in the lower third of the face with lower facial index (subnasale-stomion, stomion-menton) about the expected standards. Therefore, this expected ratio should be maintained during treatment. Lips and chin highly determine female beauty keeping in mind the divisions in the lower third of the face. Ferrario et al. reported that attractive women showed better facial characteristics in the upper third than non-attractive ones (Sforza et al., 1994). Also, the length of the nose was smaller in the skeletal class I group. DeLeon et al. reported thickness of lips to be one of the main features of beauty perception (Deleon, 2018).
In some cases, image distortions may also in luence the pictures taken and change the manner in which it is appreciated. In the present study, values for vertical length parameters which should be in relation determined by ideal proportions differed in the group between skeletal class II, III malocclusions (Katona et al., 1995). Therefore, faces of skeletal class I proportions are closer to the ideal proportions (Moss et al., 1995). Gomes et al. carried out signi icant research on neoclassical esthetics, while others seem to be updating (Gomes, 1990). According to their research, reductions in facial middlethird, in the distance between eyes and nose dimensions have occurred as well as relative enlargement of eyes and mouth width. These guidelines regarding facial beauty can improve patients facial appearance (Alsulaimani and Batwa, 2013). Clinicians must be aware that each person can have their beauty perception, so these results should be viewed with caution.

CONCLUSIONS
Facial beauty and determinants are one of the more arguable topics among surgeons, dentists and