Summary
The philtrum length, the distance from the base of the nose to the top of the upper lip, has been studied for its differences between genders and impact on attractiveness. Shin et al. (2014) found that various aspects of the upper lip, including philtrum length, are larger in males than females. Zankl et al. (2002) also observed that males tend to have a longer philtrum. Lakhiana and Somenek (2019) noted that females have shorter, fuller upper lips, implying that males have a longer upper lip and consequently a longer philtrum. Lastly, Nunes and Bran (2021) linked larger philtrum length with higher perioral attractiveness and a more youthful appearance, suggesting that more pronounced philtral contours, common in larger philtrum, are aesthetically desirable.
Research
Philtrum length is defined as the distance from the base of the nose to the top of the upper lip (also referred to as the Height of the Philtrum or HP). According to Shin et al. (2014) in the study titled “Morphometric Analysis of the Upper Lip in Koreans”, the width of the superior and inferior philtrum, the height of philtrum, the width of the mouth, and the height of the upper red lip were significantly larger in males than in females.
Likewise, another study carried out by Zankl et al. (2002) titled “Growth charts for nose length, nasal protrusion, and philtrum length from birth to 97 years” reached the same conclusion that “philtrum length tend to be larger in males than in females”.
Lastly, why larger philtrum length is better is answered by a recent study from Nunes and Bran (2021) which concluded that philtral contours significantly impact perioral attractiveness and their absence leads to a longer appearance of the upper lip and an older facial appearance. In this study, the existence of defined philtral contours is linked to higher perioral attractiveness. Since a larger philtrum typically means more pronounced contours, it could enhance the overall attractiveness of the mouth area. Similarly, the study associates the absence of philtral contours with an older facial appearance. Conversely, a larger philtrum, which would likely have more noticeable contours, could contribute to a more youthful appearance.
Reference
Shin, K. J., Gil, Y. C., Song, W. C., Koh, K. S., & Choi, H. G. (2014). Morphometric analysis of the upper lip in Koreans. Facial Plastic Surgery, 30(05), 587-592. https://sci-hub.wf/10.1055/s-0034-1393698
Zankl, A., Eberle, L., Molinari, L., & Schinzel, A. (2002). Growth charts for nose length, nasal protrusion, and philtrum length from birth to 97 years. American journal of medical genetics, 111(4), 388-391. https://onlinelibrary.wiley.com/doi/full/10.1002/ajmg.10472
Nunes, D., & Bran, G. (2021). The impact of the philtrum on facial attractiveness, perioral proportions, and perceptions of facial aging. Aesthetic Surgery Journal, 41(7), 816-825. https://doi.org/10.1093/asj/sjaa174