Summary
A smaller bi-gonial width is considered a feminine feature, while a larger one is a masculine one. Two studies, one by Lakhiani and Somenek (2019) and another by Becking et al. (2007), explain the differences between male and female jaw structures, emphasizing bi-gonial width, the distance between the jaw corners. Men’s jaws are typically larger, wider, and square-shaped, resulting in a wider bi-gonial width, recognized as a masculine feature. They also have more pronounced jaw angles due to bigger bone size and thicker muscles, enhancing their masculine appearance. Conversely, women have smaller, narrower jaws with rounder angles, leading to a smaller bi-gonial width, a feminine feature. Additionally, women’s chins are often more pointed or rounded due to a single middle bump, while men’s chins are squarer due to two bumps near the canine teeth. The studies collectively conclude that a wider bi-gonial width is a male trait, while a narrower one is a female characteristic.
Research
The study describes some of the typical differences in the mandible (lower jaw) structure between males and females, explaining why a smaller bi-gonial width (the distance between the two lowest points of the mandible, just before the angle of the jaw) is considered a feminine feature, and a larger one is considered masculine.
Men generally have bigger, wider, and taller jaws, giving them a more square-looking jawline and chin. These factors lead to a larger bi-gonial width, which is thus considered a masculine feature. Women, on the other hand, usually have smaller, narrower jaws and softer angles. Their jaws transition smoothly from the jawline to the chin, making their overall jaw width (or bi-gonial width) smaller. Additionally, women’s chins usually look more rounded or pointed because of a single bump in the middle. Men, on the other hand, often have a squarer chin because of two bumps near where the canine teeth are located. This difference in chin shape also makes women’s jaws appear narrower, which is seen as a more feminine feature. This also contributes to the perception of a smaller bi-gonial width as a feminine feature.
According to Becking et al. (2007), men’s jaws are generally bigger and have sharper angles, which makes their jaws look more square. They also have a wider jaw because of extra width or “flare” in the jawbone. This gives them a larger distance, called bi-gonial width, between the corners of the jaw. Women, on the other hand, have softer, rounder jaw angles and lack the extra width or flare. This results in a narrower jaw, hence a smaller bi-gonial width, giving them a gentler look.
Plus, men’s jaws are more pronounced due to their larger bone size and thicker muscle covering, particularly in the region of the jaw-closing muscle, which makes the lower edge and angle of the jaw more visible. This pronounced angle is seen as a manly feature. So, in short, a bigger bi-gonial width (or wider jaw) is viewed as a male feature, while a smaller one is seen as a female feature.
References
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
Becking, A. G., Tuinzing, D. B., Hage, J. J., & Gooren, L. J. (2007). Transgender feminization of the facial skeleton. Clinics in plastic surgery, 34(3), 557-564. https://www.sciencedirect.com/science/article/abs/pii/S0094129807000673