Smile Design
What is Smile Design?
Smile Design is a multipurpose conceptual protocol that provides remarkable advantages:
- The diagnostic abilities are facilitated through an extra-and-intra oral aesthetic and structural evaluation.
- Improved communication between the team members provides a better visual perception, education, and motivation for patients.
- Increased effectiveness of case presentation and accordingly case acceptance.
The goal of an esthetic makeover is to develop a peaceful and stable masticatory system, where the teeth, tissues, muscles, skeletal structures, and joints all function in harmony (Peter Dawson). It is very important that when planning treatment for esthetics cases, smile design cannot be isolated from a comprehensive approach to patient care. Achieving a successful, healthy and functional result requires an understanding of the interrelationship among all the supporting oral structures, including the muscles, bones, joints, gingival tissues, and occlusion.
Facial Composition
Facial beauty is based on standard esthetic principles that involve proper alignment, symmetry, and proportion of the face. In classical terms, the horizontal and vertical dimensions for an ideal face are as follows:
Horizontal
- The width of the face should be the width of five “eyes”.
- The distance between the eyebrow and chin should be equal to the width of the face.
Vertical
- The facial height is divided into three equal parts from the forehead to the eyebrow line, from the eyebrow line to the base of the nose, and from the base of the nose to the base of the chin.
- The full face is divided into two parts, the eyes being the midline.
- The lower part of the face from the base of the nose to the chin is divided into two parts, the upper lip forms one-third of it, and the lower lip and the chin two-thirds of it.
Tooth dimensions
Various guidelines for establishing correct proportions in an esthetically pleasing smile are:
- Golden proportion (Lombardi).
- Recurring esthetic dental proportions (Ward).
- M proportions (Methot).
- Chu’s esthetic gauges.
Golden proportion (Lombardi):
When viewed from the facial, the width of each anterior tooth is 60% of the width of the adjacent tooth (the mathematical ratio being 1.6:1:0.6). It is difficult to apply as patients have different arch forms, lip anatomy, and facial proportions. Strict adherence to golden proportion calculations limits creativity and this may lead to cosmetic failure.
M proportions (Methot):
This method compares the tooth width with the facial width using a software. The whole analysis is done on the computer and hence involves more mathematics rather than artistic analysis.
Recurring esthetic dental proportion (Ward):
The successive width proportion when viewed from the facial aspect should remain constant as we move posteriorly from the midline. This offers great flexibility to match tooth properties with facial proportions.
Chu’s esthetic gauges:
Dr. Chu’s research supports Levin’s RED concept and refutes the golden proportion. A series of gauges are available to make intraoral analysis easier. The gauges allow for:
- Fast, simple analysis and diagnosis of tooth width problems, tooth length problems, and gingival length discrepancies.
- Color coding predefines desired tooth proportions, quicker and easier to read than any other instrument.
- Used as a reference guide between clinician and lab technician, hence reducing the incidences of miscommunications errors.