Is there a reason to do a sleep study other than to determine if you have sleep apnea or rls? thank you.

Depends: On the symptoms. There are several conditions shown by a sleep study. Sleep apnea is probably commonest.

Yes: When i construct dental mouthpieces for snoring and sleep apnea, i will not make one unless the patient has an up-to-date sleep study. Often, i see patients who cannot or won't tolerate the CPAP machine (which is the gold standard.) but i will not make the mouthpiece as an alternative unless their sleep study is fairly recent.