It is imperrative for a dental practitioner involved in any treatment that will alter a patient's facial appearance, whether through orthodontics, corrective jaw surgery or aesthetic dentistry, to know and understand facial aesthetics. Even the simplest procedure such as tooth coloured composite resin restorations needs aesthetic principles to ensure optimal clinical and aesthetic results. In terms of aesthetic dentistry, innovative techniques as teeth whitening and minimally invasive veneers are very much in demand and aesthetic improvement should not be limited to the teeth. The entire framework of the face should be considered, such as the perfect midline, golden proportions, whiter teeth and correct occlusion, as well as the immediate areas that surround and outline the mouth, i.e., the extraoral and perioral areas. For example, unsightly marionette lines, nasolabial folds (commonly known as 'smile lines' or 'laugh lines') and downward labial commissures detract from the straight, white teeth of the patient, thus marring the desired aesthetic goal. It is important that dental practitioners provide a complete aesthetic service that includes the soft and hard tissues in both intraoral and perioral areas.
ANATOMICAL POINTS TO CONSIDER IN FACIAL AESTHETICS
1. Midline of the face. The line bisecting the face into left and right sides serve a guide for the position and direction of the midline of the teeth. The adjoining lines of the incisors must align with this imaginary line, which should fall directly on the middle of the philtral columns. Thus, the midline of the teeth is a very important part of the smile design process.
2. Horizontal line between the pupils of the eyes. This line is used as a guide in lining up the bottom edges (incisal edges) of the upper front teeth.
3. Horizontal line through the widest part of the cheekbones. This distance divided by 16 provides the ideal width of the upper central incisors, i.e., golden proportion. (The golden proportion of dental aesthetics indicates that the ideal aesthetic proportion for the teeth should be such that the lateral incisors are two thirds the width of the central incisors, the canine should be two thirds the width of the lateral incisors and so on.)
4. Horizontal line from one corner of the lip to the other. This identifies the plane of the incisal edges, and the best smile design requires the horizontal plane of the front teeth to follow this line. However, if lip movement is not symmetrical, the plane of the incisal edges are modified to slightly follow the smile.
5. Vertical lines from the pupil of the eye to the corner of the mouth. These lines constitute the ideal width of the mouth on smiling.
6. Smile line. The curve of an imaginary line drawn along the edges of the upper teeth from one side of the mouth to the other should ideally be aligned with the curve of the lower lip.
7. Smile profile. In the ideal smile profile, the edges of the upper incisors should contact with the wet part of lower lip; thus, a complete profile assessment of the smile, especially the relationship of the upper incisors with the lower lips, is imperative.
ANATOMICAL POINTS TO CONSIDER IN FACIAL AESTHETICS
1. Midline of the face. The line bisecting the face into left and right sides serve a guide for the position and direction of the midline of the teeth. The adjoining lines of the incisors must align with this imaginary line, which should fall directly on the middle of the philtral columns. Thus, the midline of the teeth is a very important part of the smile design process.
2. Horizontal line between the pupils of the eyes. This line is used as a guide in lining up the bottom edges (incisal edges) of the upper front teeth.
3. Horizontal line through the widest part of the cheekbones. This distance divided by 16 provides the ideal width of the upper central incisors, i.e., golden proportion. (The golden proportion of dental aesthetics indicates that the ideal aesthetic proportion for the teeth should be such that the lateral incisors are two thirds the width of the central incisors, the canine should be two thirds the width of the lateral incisors and so on.)
4. Horizontal line from one corner of the lip to the other. This identifies the plane of the incisal edges, and the best smile design requires the horizontal plane of the front teeth to follow this line. However, if lip movement is not symmetrical, the plane of the incisal edges are modified to slightly follow the smile.
5. Vertical lines from the pupil of the eye to the corner of the mouth. These lines constitute the ideal width of the mouth on smiling.
6. Smile line. The curve of an imaginary line drawn along the edges of the upper teeth from one side of the mouth to the other should ideally be aligned with the curve of the lower lip.
7. Smile profile. In the ideal smile profile, the edges of the upper incisors should contact with the wet part of lower lip; thus, a complete profile assessment of the smile, especially the relationship of the upper incisors with the lower lips, is imperative.