Summary
The bi-gonial width (distance between jaw’s lateral points) and bi-zygomatic width (distance between cheekbones’ lateral points) determine facial shape, differing in males and females. Altman (2012) found males have wider bi-gonial widths due to angular jaws, resulting in a larger bi-gonial to bi-zygomatic ratio. Lakhiani and Somenek (2019) observed that males’ inter-zygomatic width equals their bi-gonial width, indicating a square facial structure, unlike females with a smaller ratio and more oval faces. Windhager et al. (2011) correlated larger ratios in males with traits like attractiveness and masculinity, highlighting the bi-gonial to bi-zygomatic ratio’s significance in perceptions of male facial attractiveness.
Research
The bi-gonial width refers to the distance between the most lateral points of the lower jaw (at the gonion points), while the bi-zygomatic width is the distance between the most lateral points of the cheekbones (at the zygion points). The ratio of these widths provides insights into the overall shape and structure of the face, particularly distinguishing male and female facial features.
According to Altman (2012), male faces are described as more square and angular, with a strong jaw and chin. This angularity usually translates to a wider bi-gonial width, as the distance between the most lateral points of the lower jaw (gonion points) is greater due to the pronounced squareness of the jawline. Moreover, the study mentioned that the chin and lower jaw are usually longer in males by about 20%, and often more prominent in profile. Hence, a longer and more prominent lower jaw typically means a larger gonial width. Therefore, males have a larger bi-gonial width with a strong jawline, and their bi-gonial to bi-zygomatic ratio is larger.
Additionally, another study by Lakhiani and Somenek (2019) determined that in males, the inter-zygomatic width is almost equal to the bi-gonial width. This implies that the distance between the cheekbones is similar to the width of the lower jaw. Therefore, when calculating the bi-gonial to bi-zygomatic ratio (which compares the width of the jawline to the width of the cheekbones), the two measurements being nearly equal leads to a higher ratio. Hence, males have a nearly equal inter-zygomatic and mandible width, their bi-gonial to bi-zygomatic ratio is larger, indicating a more square or rectangular facial structure. In contrast, females, with a wider inter-zygomatic width compared to their mandible width, have a smaller ratio, indicative of a more oval or heart-shaped facial structure.
Moreover, a recent article by Windhager et al. (2011) titled “Geometric morephometrics of male facial shape in relation to physical strength and perceived attractiveness, dominance, and masculinity” suggested that males have prominent cheekbones and a pronounced chin area which aligns with the characteristics of a larger bi-gonial to bi-zygomatic ratio. In males, a larger ratio indicates a wider jawline relative to the cheekbones. This broader jaw (bi-gonial width) coupled with prominent cheekbones (bi-zygomatic width) contributes to a more defined and angular facial structure, which is identified as a trait of male attractiveness in this study.
The significance of the bi-gonial to bi-zygomatic ratio in males is not just a matter of anatomical measurement but also ties deeply with perceptions of attractiveness, masculinity, and strength. Studies have consistently shown that a larger ratio, indicative of a wider jawline and more angular facial structure, is associated with attributes traditionally deemed desirable in male faces.
Reference
Altman, K. (2012). Facial feminization surgery: current state of the art. International journal of oral and maxillofacial surgery, 41(8), 885-894. https://doi.org/10.1016/j.ijom.2012.04.024
Lakhiani, C., & Somenek, M. T. (2019). Gender-related facial analysis. Facial Plastic Surgery Clinics, 27(2), 171-177. https://www.facialplastic.theclinics.com/article/S1064-7406(19)30006-9/fulltext
Windhager, S., Schaefer, K., & Fink, B. (2011). Geometric morphometrics of male facial shape in relation to physical strength and perceived attractiveness, dominance, and masculinity. American Journal of Human Biology, 23(6), 805-814. https://doi.org/10.1002/ajhb.21219