Complex sentence: Although academic dress is now rarely worn outside commencement ceremonies or other academic rituals such as encaenia in the U.S. graduation ceremonies have gained popularity and have expanded from high school graduations to middle school, elementary school and kindergarten graduation ceremonies.
Split into simpler sentences: Although academic dress is now rarely worn outside commencement ceremonies or other academic rituals such as encaenia. In the U.S. graduation ceremonies have gained popularity and have expanded from high school graduations to middle school, elementary school and kindergarten graduation ceremonies.