The Design
The ADA uses as its central figure a variation of the staff of Asclepius. In the background of the design are branches of 32 leaves and 20 berries, representing the number of permanent and primary teeth. The symbol is surrounded by an intersecting triangle and circle forming the periphery of the design. The Greek letter Δ (delta) represents the letter D in the word dentistry. The Greek letter Ο (omicron) represents “odont” meaning tooth. - See more at: http://www.deardoctor.com/dentistry/blog/meaning-behind-the-official-symbol-of-dentistry#sthash.MzeWda1G.dpuf