Anatomical considerations on the masseteric fascia and superficial muscular aponeurotic system.

The masseteric region is considered by the most researchers as a subdivision of the parotideomasseteric region. Because of its surgical significance, we emphasize it has distinctive morphofunctional features. The aim of this manuscript is to highlight particular characteristics of the masseteric region and practical applications of this concept. The material used was represented by 12 embalmed cephalic extremities dissected in "Ion Iancu" Institute of Anatomy, "Grigore T. Popa" University of Medicine and Pharmacy, Iaşi, 10 operating specimens from the Clinics of Maxillofacial Surgery and Plastic Surgery of the "St. Spiridon" University Hospital, Iaşi, Romania, and computed tomography (CT) and magnetic resonance (MR) images from the same patients. Our results underline the importance and individual arrangement of the superficial muscular aponeurotic system (SMAS) of the face, at the level of masseteric region. The superficial fascia facilitates adhesion to the dermis of the mimic muscles of the region. This reveals that the masseteric superficial fascia will follow the masticatory movements of the mandible and masseter, but also those of the minor and major zygomaticus muscles. These muscles are the infra-SMAS layer and thus take part in the formation of a unitary complex together with the superficial fascia. The particularities of the SMAS in the masseteric region are especially important in plastic and reconstructive surgery.