Complex sentence: Since 2000, the Bogdanoff brothers have created a lot of curiosity by the sudden notable physical changes notably their faces with very angular growth of their chins and cheekbones giving them an extraterrestrial look.
Split into simpler sentences: Since 2000, the Bogdanoff brothers have created a lot of curiosity by their sudden physical changes. Most notably, their faces have changed considerably gaining a more angular growth on their chins and cheekbones, giving them an extraterrestrial look.