Aesthetic Smile Principles

Aesthetic considerations in restorative and prosthetic dentistry have attained high priority in the past few decades. As the demand on the artistic ability of the dentist to achieve esthetic smile increases, the knowledge and understanding of the smile principles become mandatory.

The principles involved in smile designing are

(i) Principle of unity
(ii) Principle of dominance
(iii) Principle of Repeated ratio
(iv) Principle of gradation
(v) Principle of illumination
(vi) Principle of illusion
(vii) Principle of metamorphism

Principle of Unity :
It is the combination or ordering the different parts of dental composition to give a single combined effect of the whole

Unity is of 2 types
(i) Static unity
(ii) Dynamic unity

Static

The line is never the same at any point along its course, yet it never leaves the surface of cone. Adoption of a line resembling a segment of the line for tooth placement and base festooning adds greatly to the dynamism of a set up and strongly recommended as a substitute for the unchanging curve of the circle. Smile designing is done in dynamic unity.
Anatomy of teeth, age, sex, personality factor festooning in denture base, dominance and various other factors aid in achieving smile design in dynamic unity.

Principle of Dominance :
According to the dominance principle, one factor has to dominate in each component of dental composition to achieve an esthetic smile.

EXAMPLE:
1. The size of central incisor has to dominate the other anterior teeth in perception for esthetic smile.
2. Similarly the shape of teeth and color of the tooth has to dominate to obtain dynamic unity. The dominance of size & color of the anterior teeth

Principle of Repeated Ratio:
It is a constant ratio, which is repeated or reproduced to maintain equidistant between the components (objects) or various elements involved in

After the founder Phidias who first employed it. Phi appears throughout life and the universe. Some believe that it is the most efficient outcome, the result of natural forces. Some believe it is a universal constant of design, the signature of God.

DIVINE PROPORTION IN HUMAN BODY
The entire human figure can be described in terms of proportionate sizes of the various parts.The head forms a golden rectangle with the eyes at its midpoint. The mouth and nose are each placed at golden sections of the distance between the eyes and the bottom of the chin. The blue line defines a perfect square of the pupils and outside corners of the mouth. The golden section of these four blue lines defines the nose, the tip of the nose, the inside of the nostrils, the two rises of the upper lip and the inner points of the ear. The blue line also defines the distance from the upper lip to the bottom of the chin.
The yellow line: a golden section of the blue line, defines the width of the nose, the distance between the eyes and eye brows and the distance from the pupils to the tip of the nose.
The green line: a golden section of the yellow line defines the width of the eye, the distance at the pupil from the eye lash to the eye brow and the distance between the