By Dr. Stephanie McGann, DMD FAGD, Columnist, The Times Buyer Beware, I heard my parents tell me that decades ago when I earned my first paycheck working as a part time lifeguard.  It was the mid 1970’s and I wanted a stereo. Yes I just dated myself. I listened to music before the ipod,earbuds and pandora.  I knew the sound of a needle skipping on a record and the horror of a cassette tape unraveling...