Over 36 million people in the US have migraines. Can evolutionary biology be a factor in this staggering number? My thought is that as our brains increased in size and the human skull accommodated to this growth, our faces changed also. Also, early humans migrated into colder areas of the planet causing changes in facial structures to accomdate to new weather patterns. These changes in many instances cause our teeth to be squished together. Our head and neck muscles then had to adjust lower jaw position constantly to allow us to be able to eat and chew food. Sometimes, some muscles become spastic in trying to hold an efficient jaw position. They become inflamed causing pain in the head and neck region. These muscles also release cytocines that can and do cross the Blood-Brain-Barrier then causing changes in brain
functioning. Since the 5th nerve sends about 1/3 of all sensory impulses to the brain, any muscles innervated by that nerve may be a root cause in headaches and migraines.