The most important component of the skin, that influences the way that a wound will heal is collagen, and in this case, type III collagen. Type I collagen is found in the skin, where it makes a network that draw invisible traction lines.[1]
According to Karl Langer, the first anatomist to search this subject in 1861, the human skin has a certain pattern. He observed this while doing research on cadavers with rigor mortis.
In 1999 Wilhelmi BJ and Co. published an article called "Langer's lines: to use or not to use" in which he claimed that the best incision lines are not Langer's, but ones made by Borges and Kraissl. The important detail observed in 1984 by Albert F. Borges was that in living humans traction lines differ a little bit. And so he formulated "Relaxed Skin Tension Lines", which are considered to be guideline for facial surgery.
The best lines for body surgery is considered to be the one made by Cornelius J. Kraissl, because the healing process is faster and the scars post-incision are usually smaller.[3]
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1. http://www.ncbi.nlm.nih.gov/books/NBK21582/
2. http://www.med-ars.it/galleries/langer.htm
3. The Encyclopedia of Cosmetic and Plastic Surgery; Rinzler C.A.; Facts on File Inc; 2009
