According to the publisher of Aesthetic Buyer's Guide, microdermabrasion has become the most popular and highest volume facial rejuvenation procedure in the world. Microdermabrasion, which was cleared for use in the US in 1996, has become a staple in both day spas and dermatology practices. Although the microdermabrasion crystals are more powerful for medical use, manufacturers are developing 'medical grade' machines for spas that claim equal effectiveness.