TLDR The Hair Diameter Index (HDI) was created to help plan hair restoration surgery after finding that visual hair density is linked to hair count and thickness, not volume.
In 2021, a study was conducted to investigate the Hair Volume Index (HVI), a proposed measurement system for evaluating visual hair density. The results, however, did not support the idea that scalp coverage was related to the measured volume of hair in a given area. Instead, visual density was found to be correlated with the number of hairs and the hair shaft diameter. This led to the development of the Hair Diameter Index (HDI). The HDI was then applied in hair restoration surgery for follicular unit excision (FUE) donor area planning and graft implantation density.
29 citations,
March 2008 in “Dermatologic Surgery” The Cross-section Trichometer is a new tool that can measure hair quantity and detect hair loss and growth.
2 citations,
November 2001 in “Hair transplant forum international”
9 citations,
January 2018 in “Hair transplant forum international” Researchers concluded that safe hair follicle extraction limits in FUE vary by individual characteristics and proposed a method to calculate these limits to maintain appearance.
25 citations,
March 2017 in “Journal of Dermatological Treatment” Platelet-rich plasma treatment for non-scarring hair loss shows mixed results and needs more research.
8 citations,
January 2016 in “European Journal of Plastic Surgery” PRGF treatment is safer and more effective for hair loss than topical minoxidil.
58 citations,
January 2015 in “International Journal of Trichology” Platelet-rich plasma, which carries growth factors, could be a promising treatment for non-scarring hair loss, promoting hair growth and density with no major side effects.
27 citations,
October 2016 in “The Journal of Clinical Endocrinology and Metabolism” Daughters of women with PCOS generally experience normal puberty but may have more body hair and different body fat distribution.
