Night time teeth grinding known as sleep bruxism is the third most common sleep disorder, occurring in 8% of adults. Sleep bruxing or grinding is a sleep disorder that occurs 80 percent of the time with sleep apnea. It occurs together with a sleep apnea event. The forces generated through night time grinding is a lot more than that of daytime grinding. The two major muscles involved are the masseter and the temporalis. With sleep bruxism there is a series of events starting with an increase in heart rate and blood pressure, an increase in eeg activity, contraction of the masseter and temporalis muscle, and concludes with a swallowing reflex. Most of the teeth damage that patients present with such as broken teeth, myofascial pain, muscle spasms, disc problems are cause by night time grinding, not daytime grinding. Since tmj treatment and sleep apnea treatment overlap in a lot of areas, many times the treatment is the same. Many times an oral device that treats sleep apnea will also take care of the night time bruxing. At Laguna Hills Center for Sleep Apnea we screen all of patients for both tmj and osa (obstructive sleep apnea).