Evaluation of the Golden Proportion, Golden Percentage, and Recurring Esthetic Dental Proportion in Kenyans of African Descent

Abstract

Objectives: To evaluate the validity of the Golden Proportion, Golden Percentage, and Recurring Esthetic Dental (RED) Proportion among Kenyans of African descent with naturally well-aligned teeth.

Materials and methods: Standardized frontal photographic images of the smiles of 175 participants aged 18-35 years were obtained, and Adobe Photoshop was used to analyze and measure the frontal widths of the maxillary central and lateral incisors and canines in triplicate. The average teeth widths were calculated to determine the existence of the Golden Proportion, Golden Percentage, and RED Proportion, and their validity using independent sample t-tests to compare the differences in the mean teeth widths at α < 0.05.

Results: The number of male and female participants was 107 (61.1%) and 68 (38.9%), respectively. The Golden Proportion between the maxillary central and lateral incisors was found in 4.0% on the right and 2.8% on the left of all the participants, but between the maxillary lateral incisors and canines was found in only 0.6% on the right of male participants (p < 0.0001). The RED Proportion between the maxillary lateral and central incisors was in the range of 67%-70%, and between the canines and lateral incisors was 82%-84% (p < 0.0001). The proportion of RED was not constant, and gradually increased distally. The Golden Percentage of 15% was observed in the lateral incisors bilaterally; however, in the central incisors and the canines, the Golden Percentage was 22% and 12%, respectively.

Conclusion: The Golden and RED Proportions were invalid determinants of anterior teeth proportions. The Golden Percentage existed only in the lateral incisors. The Golden Proportion, RED Proportion, and Golden Percentage theories may not be applicable to all populations when designing smiles. Racial and ethnic backgrounds are important considerations to establish objective quantifiable values of anterior tooth proportions that are beneficial for esthetic restorations.

Keywords: Golden Percentage; Golden Proportion; Recurring Esthetic Dental Proportion; maxillary anterior tooth proportions.

Figure 1

Study participants recruitment process.

Figure 2

Illustration of the measuring points—A: widest smile displaying the maxillary anterior teeth; B—the widths of the maxillary incisors were measured at the mesio‐distal contact points of the teeth (b–c for central incisors and c–d for lateral incisors), the width of the canine was measured from the mesial contact point to the most distal point visible from the frontal view (d–e) while the frontal inter‐canine width was taken from the distal‐most visible point on the right canine to the left one (a–e); C—demarcation and measurement points of the width of 11; D—the heights of the teeth were measured from the gingival zenith to the incisal edge of the incisors or cusp tip of the canine.

Figure 3

Comparison between the suggested Golden Percentage and that found in this study (A—male participants; B—female participants; C—all participants). Lt Cent, left central incisor; Lt Can, left canine; Lt Lat, left lateral incisor; Rt Can, right canine; Rt Cent, right central incisor; Rt Lat, right lateral incisor.