[The anatomic study and clinical application of the premasseter space].

The soft tissue space superficial to the masseter muscle have two different characteristics. The different nature of the two parts of the space can easily mislead dissection to the wrong layer, which is the important anatomical factors for the risk of facial nerve damage in rhytidectomy. The layered ptosis theory seem to better explain the process of aging. The primary treatment of aged face was facial space dissection and tighten.