Date: December 2016.
Source: Master of Science Thesis, The University of Alabama at Birmingham.
Introduction: The purpose of this study is to determine the soft tissue topographical norms for the local ethnic people of Zimbabwe and compare them with the African American norms based on 3dMD soft tissue photography. The rationale for the study is to evaluate how the soft tissue drape over the facial skeleton correlates with the different soft tissue analysis widely available today. This study seeks to establish an average base on which clinicians can treat people according to their cultural esthetic perceptions. Previous reported studies only evaluate small numbers of populations and it is well known that different races and ethnic backgrounds have different facial traits. Therefore it is essential to customize measurable norms within specific populations in order to achieve the most stable and esthetic results to that group.
Materials and Methods: Three-dimensional images were captured using a stereo- Photogrammetric camera system (3dMDface System). 107 Zimbabwean males and 94 Zimbabwean females with no asymmetry or malocclusions and normal BMI of 19 and 22, respectively, were compared to each other and against 50 males and 50 females of African American descent from ages 19-30 from University of Alabama in Birmingham, Alabama, with a normal BMI and same inclusion criteria for the Zimbabwean study. The images captured from both Zimbabwean males and females, were processed by obtaining average shells. Each image was acquired as a facial mesh and oriented along a triangular axis. All facial images were overlaid and superimposed, using Rapidform 6 software to create a composite facial average for each sex.
Results: The absolute linear measurements showed that the maximum average distance between the Zim-M and Zim-F is 1.24 mm and the minimum distance between the AA-M and AA-F measured at 0.24mm. The signed linear measurement showed a maximum average distance between Zim-F and AA-M of 1.22mm and the least average distance between the Zim-M and AA-M of 0.22mm. The absolute color histograms showed greatest similarity between the Zim-M and AA-M at 58 % and the Zimbabwean females had a 25% and 27% similarity with the AA-F and Zim-M respectively. The AA-F are more protrusive in the middle forehead area (Trichion), alar base and lateral perioral region and retrusive in the lateral zygomatic region extending down vertically to the gonial and submental regions. However they displayed more prominence in the glabella, nasion, subnasale and soft tissue pogonion when compared to their African American counterpart.
Conclusions: The 3dMDface™ system can be used to map the facial topography of various populations. The Zimbabwean females showed the most variable features with a broader face, prominent forehead and retruded alar base compared to their male counterparts and the Zimbabwean males shows a wider prominent malar/zygomatic region, and prominent lateral supraorbital regions. There was a high similarity of 58% between the Zimbabwean males and the African American males, with the Zimbabwean males showing a more protrusive superciliary arch, and a lateral zygomatic reigon tapering to the root of the nose. However they have less prominent mid dorsum, nasal tip and perioral region. The similarity is 58% at 0.5 acceptable tolerance, which is the highest in comparison to the others.
Article: A comparison of soft tissue topographical norms for the local ethnic people of Zimbabwe and African American norms based on 3dMD soft tissue photography.
Authors: Elvin Bhaskar.
Date: December 2016.