The four key lip shapes identified are:
• The Apple: Rounded, high volume centrally located in the lips, soft cupid's bow
• The Bow: Smooth, long and wide shape, medium volume, broader cupid's bow, slightly more volume on bottom lip
• The Ellipses: Full volume lips, highly pronounced and project forwards
• The Heart: Archetypal lip shape, highly contoured, defined cupid's bow shape, average volume