Jawbreaker

(Combat)
You deliver a powerful strike to the mouth, breaking teeth and bone.
 

Prerequisites

Improved Unarmed Strike, Stunning Fist, Heal 6 ranks.
 

Benefit

When you make a successful Stunning Fist attempt against an opponent that is Grappled, Helpless, or Stunned, instead of imparting any other Stunning Fist effect, you can cripple that opponent's mouth, dealing normal unarmed strike damage and 1d4 points of bleed damage. Until the bleed damage ends, the target is unable to use its mouth to attack, speak clearly, and employ verbal spell components. A creature that is immune to critical hits or that has no discernible mouth is immune to the effects of this feat.
 

Combat Trick

If you have a Stamina pool, the following Combat Trick may be used with this feat.
  When you hit with a Jawbreaker attack, you can spend 5 Stamina points to increase the bleed damage to 1d6 points, increase the DC of the Heal check to end the bleed to 20, and require the user of a spell or ability that cures hit point damage to succeed at a DC 15 caster level check to end the bleed effect.