title: Deep Pyriform Space: Anatomical Clarifications and Clinical Implications.
abstract: BACKGROUND
  The purpose of this study was to define the anatomical boundaries, transformation in the aging face, and clinical implications of the Ristow space. The authors propose a title of deep pyriform space for anatomical continuity.
  
  
  METHODS
  The deep pyriform space was dissected in 12 hemifacial fresh cadaver dissections. Specimens were divided into three separate groups. For group 1, dimensions were measured and plaster molds were fashioned to evaluate shape and contour. For group 2, the space was injected percutaneously with dyed hyaluronic acid to examine proximity relationships to adjacent structures. For group 3, the space was pneumatized to evaluate its cephalic extension.
  
  
  RESULTS
  The average dimensions of the deep pyriform space are 1.1 × 0.9 cm. It is bounded medially by the depressor septi nasi and cradled laterally and superficially in a "half-moon" shape by the deep medial cheek fat and lip elevators. The angular artery courses on the roof of the space within a septum between the space and deep medial cheek fat. Pneumatization of the space traverses cephalic to the level of the tear trough ligament in a plane deep to the premaxillary space.
  
  
  CONCLUSIONS
  The deep pyriform space is a midface cavity cradled by the pyriform aperture and deep medial cheek compartment. Bony recession of the maxilla with age predisposes this space for use as a potential area of deep volumization to support overlying cheek fat and draping lip elevators. The position of the angular artery in the roof of the space allows safe injection on the bone without concern for vascular injury.
authors.affiliation: Kansas City, Kan.; and Independence, Mo.|From the Department of Plastic Surgery, University of Kansas Medical Center; and private practice.
authors.forename: Christopher K
authors.initials: CK
authors.lastname: Surek
authors.affiliation: Kansas City, Kan.; and Independence, Mo.|From the Department of Plastic Surgery, University of Kansas Medical Center; and private practice.
authors.forename: James
authors.initials: J
authors.lastname: Vargo
authors.affiliation: Kansas City, Kan.; and Independence, Mo.|From the Department of Plastic Surgery, University of Kansas Medical Center; and private practice.
authors.forename: Jerome
authors.initials: J
authors.lastname: Lamb
mesh_terms: D000273:Adipose Tissue / Q000033:anatomy & histology*; D000375:Aging; D002102:Cadaver; D005145:Face / Q000033:anatomy & histology*; D005152:Facial Muscles / Q000033:anatomy & histology; D006801:Humans; D008437:Maxilla / Q000033:anatomy & histology*