The zygomaticus major muscle is a muscle that controls facial expression, drawing the mouth's angle upward and outward.
AREAS SCM TRIGGER POINTS REFER PAIN TO :
Headaches or Migraines
The X's represent the Trigger Points apply pressure gently until your on the edge of "good" pain. The red shaded area is the referred pain caused by the Trigger Point and the darker red means more people experienced pain in that area.
Simons, David G., Lois S. Simons, and Janet G. Travell. Travell & Simons’ Myofascial Pain and Dysfunction: The Trigger Point Manual. Baltimore, MD: Williams & Wilkins, 1999.
The Trigger Point& Referred Pain Guide.