Facial feminization surgery the lower lip and is at the edges of the chin. Males tend to have a much more prominent Adam's apple than females following puberty. The Adam's apple can be reduced with a procedure called a chondrolaryngoplasty; the goal of the procedure is to reduce the size without leaving a scar. There are risks of damage to the vocal cords and destabilization of the epiglottis. Beautification and rejuvenation procedures are often performed at the same time as facial feminisation. For example, it is common for eye bags and sagging eyelids to be corrected with a procedure called "blepharoplasty" and many
Facial expression have even shown that there are similarities between species in how emotions are expressed. Research has shown that chimpanzees are able to communicate many of the same facial expressions as humans through the complex movements of the facial muscles. In fact, the facial cues were so similar that Ekman's Facial Action Coding System could be applied to the chimps in evaluating their expressions. Of course, differences between the species' physical facial properties, such as white sclera and everted lips in chimps, would mean that some expressions could not be compared. Similarly, Darwin observed that infants' method of expression for certain