Effects of facial hard tissue surgery on facial aesthetics: changes in facial content and frames.

Aesthetic units of the face can be divided into facial content (FC; eyes, nose, lips, and mouth), anterior facial frame (AFF; a contour line from the trichion, the temporal line of the frontal bone, the lateral orbital rim, the most lateral line of the anterior part of the zygomatic body, the anterior border of the masseter muscle, to the inferior border of the chin), and posterior facial frame (PFF; a contour line from the hairline, the zygomatic arch, to the ramus and gonial angle area of the mandible). The size and shape of each FC and the balance and proportion between FCs create a unique appearance for each person. The facial form can be determined through the combination of AFF and PFF. In the Asian population, clinicians frequently encounter problems of FC (eg, acute nasolabial angle, protrusive and everted lips, nonconsonant lip line, or lip canting), AFF (eg, midface hypoplasia, protrusive and asymmetric chin, vertical deficiency/excess of the anterior maxilla and symphysis, or prominent zygoma), and PFF (eg, square mandibular angle). These problems can be efficiently and effectively corrected through the combination of hard tissue surgery such as anterior segmental osteotomy, genioplasty, mandibular angle reduction, malarplasty, and orthognathic surgery. Therefore, the purposes of this article were to introduce the concepts of FC, AFF, and PFF, and to explain the effects of facial hard tissue surgery on facial aesthetics.