Dental Esthetics And The Golden Proportion

Dental Esthetics And The Golden Proportion

Question. Define golden proportion with its significance in dental esthetics and add a note on the applications of various proportions in dental esthetics.
Answer:

Golden proportion According to GPT

• The golden proportion is the ratio between succeeding terms in a mathematical progression called the Fibonacci series (Leonardo Pisano: nickname Fibonacci) in which each number is the sum of the two immediately preceding it (i.e., 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, and so on).
• The ratio converges at approximately 1.618 to 1. Claims have been made that the Golden Proportion exists in natural dentitions in the ratio of the widths of incisors and canines as seen from the facial surfaces.

Read And Learn More: Complete Dentures Question and Answers

Golden Proportion in Dentistry

Lombardi (1973) was the first to suggest the application of the golden proportion in dentistry. Levin (1978) suggested the golden proportion to relate the successive width of the anterior teeth as viewed from the labial aspect.

Application of Golden Proportion in Dental Esthetics

• To develop ideal size and shape relationships for maxillary teeth and to determine the width of the teeth.
• Golden proportion can be applied only after determining the incisal edge position, incisal plane, gingival plane, and central incisor length.
• As applied to the maxillary teeth, the Golden Proportion requires a 62% reduction in the viewing width of each tooth, beginning with the central incisor, and proceeding posteriorly.
• To apply the concept of the Golden Proportion, a lateral incisor can be arbitrarily assigned a viewing width of 1, in which the central incisor width should be 1.6, the cuspid 0.62, the first premolar 0.38, and the second premolar 0.23. This allows for a smile dominated by the central incisors, with the other teeth becoming progressively smaller.

Modifications of Golden Proportion

• Snow proposed that the Golden Proportion could be used to develop symmetry, dominance, and proportion for esthetically pleasing smiles.
• The assigned values for the six anterior teeth were added (assigning 1.6 to the central, 1 to the lateral, and 0.62 to the cuspid).
• Then the assigned width of each tooth was divided by the total to determine the relative percentage. The resulting percentages were: central incisor 25%, lateral incisor 16%, and cuspid 9%.
• These percentages illustrate the dominance of the central incisors, which are 50% of the cuspid-to-cuspid width.

Dr. Stephen Marquardt, an eminent Oral Surgeon in California, discovered that” The Height of the central incisor is in the Golden Proportion to the Width of the Two central incisors”.

Daniel H Ward proposed the recurring esthetic dental proportion (red)

• When the golden proportion is used, lateral incisors seem to be too narrow and canine is not prevalent enough hence proposed a RED proportion or Recurring Esthetic Dental Proportion.
• According to this, the dentist can establish his own proportion and remain consistent while moving distally. 70% seems to be more pleasing but should be modified to fit the face’s skeletal structure and general body type.

Golden proportion  Red Smile Design (Recurring esthetic dental proportion)

• The equation used to determine the ideal width of a central incisor from a predetermined RED proportion is:
• (Frontal Intercanine View width of the anterior 6 teeth)/2(1+RED + RED2) = width of central incisor
• Using this formula, if the frontal inter canine view width of the maxillary anterior 6 teeth is 37.2 mm and the desired RED is 70%, the calculated width of the central incisor would be 8.5 mm.

Golden proportion  Preston and RED Proportion

The central incisors are identical in size in both the Preston and 70% RED proportions. The lateral incisors are slightly wider in the 70% RED proportion, while the canines are slightly wider in the Preston proportion.

Golden proportion  Once the width of the central incisor has been established, the height can be determined by using the formula:

(Width of central incisor / Width-to-height ratio) = height of central incisor

(The width-to-height ratio should be expressed as a decimal <1)

• If the teeth are relatively short and the patient will not allow a change in length, a larger RED should be used.
• When there are no possible changes to the widths of the central incisors, the heights may be altered either by lengthening the incisal edges or performing elective periodontal crown lengthening surgery.
• The final length of the teeth and RED proportion used should ideally coincide with the patient’s facial and body structure.
• The RED Proportion is an objective method of evaluating and designing smiles.