Facial Attractiveness and Orthodontics: An Overview

INTRODUCTION

The concept of aesthetics is constantly changing, and in the last few decades, it has become increasingly significant in the orthodontics field. In the context of orthodontics, the significance of aesthetics cannot be overstated, but it has frequently been viewed as secondary to reaching a perfect occlusion for an ideal functional occlusion.¹

Edward H. Angle² dedicated chapter II (8 pages) of his textbook's sixth edition, which was released in 1900, to "Facial art—line of harmony." He discussed regarding his "line of harmony," a vertical line that "perfectly harmonizes" with the glabella, subnasale, and pogonion in the profile.³

Lately, aesthetics is a necessary component of the idealized treatment goal and is required to attain a satisfactory result. Prior to treatment, it is important to acknowledge the patient's perception of their face because an orthodontist's and layperson's perspectives on aesthetics differ.^4,5 Furthermore, rather than strict adherence to typical average skeletal and dental norms, the treatment goals should aim for a balanced and harmonious facial profile.⁶

ASSESMENT OF DENTAL ESTHETICS

The three fundamental prerequisites for evaluating dentofacial esthetics are: A dynamic and static three-dimensional assessment of the face during clinical evaluation, an analysis of the relationship between the lips and teeth, and an examination of the anterior teeth's display (both at rest and function)⁷

The following are the three aesthetic divisions assessed in orthodontic diagnosis:

1. Macroesthetics
2. Miniesthetics
3. Microesthetics

MACROESTHETICS

Frontal and lateral (profile) assessment is done

An ideal proportion of face can be divided transversely into equal fifths. The central and medial fifths should determine the eyes' width and separation. With the nose's width equal to or marginally greater than the central fifth, the chin and nose should be cantered within it. The interpupillary distance and mouth width should ideally match.⁸ (Fig. 1)

Convex, concave, and straight profile estimations are used as a guide to ascertain the underlying skeletal relationship and whether the jaws are positioned proportionately in the anteroposterior plane.

Evaluating the vertical thirds of the face and the mandibular plane in a lateral view helps identify vertical growth patterns. A steep mandibular plane angle is typically linked to a longer anterior facial height and a tendency toward a skeletal open bite, while a flatter mandibular plane angle is usually associated with a shorter anterior facial height and a deep bite malocclusion.⁸ (Fig. 2)

MINIESTHETICS

BUCCAL CORRIDOR AND ARCH FORM

It refers to the area between the buccal surface of the posterior teeth and the corner of the lips when a person smiles.9 The existence of buccal corridors is thought to contribute to a more natural-looking smile. However, research has indicated that wider buccal corridors can result in a smile that is perceived as less attractive.¹⁰ (Fig. 3)

SMILE ARC

It refers to the relationship between the curvature of the upper incisors and canines' incisal edges and the curvature of the lower lip when smiling.¹¹ There are three types of smile arcs: parallel (consonant), straight, and reverse. The ideal outcome is to achieve a parallel smile arc.¹² (Fig.4)

INCISAL DISPLAY

For a smile to be aesthetically pleasing, at least 75% of the maxillary teeth should be visible, though displaying up to 4 mm of gingiva or having 4 mm of lip coverage over the incisor crown is considered acceptable.¹³ The most visually appealing smiles have the upper lip aligning with the gingival margin of the upper central incisor. Tjan et al.¹⁴ identified three smile types - low, average, and high based on the amount of incisor and gum visibility. (Fig. 5)

DENTAL MIDLINE

A vertical line drawn from the nasion to the base of the philtrum can serve as a useful reference for identifying the facial midline. During a direct frontal examination, the maxillary midline should ideally be vertical and parallel to the facial midline, or, in the best case, align perfectly with it. (Fig.6)

MICROESTHETICS

TOOTH PROPORTIONS

For a visually balanced smile based on the golden proportion, the apparent width of the lateral incisor should be 62% of the width of the central incisor. Similarly, the apparent width of the canine should be 62% of the lateral incisor, and the apparent width of the first premolar should be 62% of the canine.⁸ (Fig. 7)

HEIGHT–WIDTH RELATIONSHIPS

The ideal width of a tooth is typically 80% of its height, with Sterrett et al.¹⁵ suggesting a range between 0.75 and 0.85. For a central incisor, the width generally falls between 8.1 to 8.6 mm, while the length ranges from 9.5 to 10.2 mm.¹⁶ (Fig. 7)

CONNECTORS AND EMBRASURES

The connector area refers to the point of contact between adjacent teeth, while embrasures are the triangular spaces located above this contact, towards the incisal edge.¹¹ (Fig. 7)

GINGIVAL HEIGHT

Generally, the gingival margin of the central incisor and canine are at the same height, whereas the margin of the lateral incisor is positioned 1.5 mm lower. (Fig. 7)

GINGIVAL SHAPE

The gingival shape of the maxillary central incisors and canines is elliptical, with the gingival zenith positioned slightly distal to the tooth’s long axis. In contrast, the gingival shape of the maxillary lateral incisors and mandibular incisors should be symmetrical, resembling a half-oval or half-circle, with the gingival zenith aligning with the tooth’s long axis.¹⁷ (Fig. 7)

GINGIVAL CONTOUR

Gingival contouring to remove excess gingival tissue is typically performed through periodontal procedures such as gingivectomy or crown lengthening. On the other hand, gingival recession is commonly addressed with tissue grafts, guided tissue regeneration, or, in certain cases, non-surgical orthodontic extrusion. (Fig. 7)

TOOTH SHADE AND COLOR

The maxillary central incisors are the lightest and most vibrant, with the brightness gradually decreasing in the following teeth. The hue of the maxillary lateral incisors is similar to the centrals, though they are less bright. The canines are the dullest teeth, having the highest chroma (color saturation). The 1st and 2nd premolars, on the other hand, are more similar in color to the laterals and are brighter than the canines. (Fig. 7)

CONCLUSION

The revival of the soft tissue paradigm represents a major shift in orthodontics, focusing not only on achieving optimal occlusion but also on improving both dental and facial appearance. This integrated approach takes into account the aesthetic profile of the patient as a crucial element in treatment planning, recognizing that a pleasing facial appearance is as critical, if not more so, than achieving functional dental alignment. By focusing on both functional outcomes and esthetic enhancements, orthodontists can provide patients with results that contribute to both improved health and greater self-confidence.

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