Tip for finding heads on bricklink
Here is some tips for finding minifigure heads on bricklink.
Here is what bricklink calls bared teeth
Bricklink calls this a lopsided grin / lopsided smile
This is an eye mask
Any heads with glasses will come up under "glasses"
This is what they called cheek lines
These heads will typically come under "(colour)" hair
This is a mustache this example it is called a "bushy mustache"
This head is rare, but the pink dots are "bee stings"
This is a "unibrow"
This is a "scowl"
This head's eyebrows are under raised eyebrow, and the black under his mouth is usually a goatee
These dotted beards are called "stubble beards. Also if you see a tongue in/out the mouth it is called just a "tongue".
Female heads will standardly go under "female head with (colour) lips" Look at other tips for shorter lists to scroll through ;)
This is an angular beard where he beard's cut squarely.
Heads like this are under freckles
This man's mouth is a "determined grin", where it is an open mouth with and a lopsided grin
This is a dual sided head, commonly mistaken as a double-sided head. (This is also a determined grin)
The second side of this is a "scared head". Usually the bottom of the mouth is flat and the top has a dip, and there is teeth lines at the end.
Not all head descriptions use this, but this is an arched eyebrow
The lower beard's sides of this head is a "side burns"
Concerned faces are usually very straight, and not that long
As we all know, these are simpsons heads