If you divide the head into four equal sections the first quarter is from the top of the head to the front hairline.
The second quarter ends at the lower line of the eye The bottom of the eyes falls roughly on the ½ way point between the top of the head and the chin.
The third quarter ends at the base of the nose
In the fourth quarter the mouth is just above the midway point between the bottom of the nose and the chin.
The bottom of the nose is halfway between the eyes and the chin
The mouth is halfway between the nose and the chin.
The top of the ears is at the line of the eyebrows.
The bottom of the ears is just above the bottom of the nose.