RESUMO
OBJECTIVE: The purpose of this cadaver dissection study was to investigate the anatomy of the nasolabial fold with a view to explaining the problems of surgical softening or elimination of the fold. STUDY DESIGN: Ten formalin-fixed cadavers and 6 fresh-frozen cadavers were used for this study. In 12 cadavers (8 formalin-fixed, 4 fresh-frozen), the nasolabial fold was sectioned at right angles to the fold for histologic examination, and in 4 cadavers (2 formalin-fixed, 2 fresh-frozen) the epithelium was dissected off the fold to allow for more detailed gross examination of the underlying musculature. RESULTS: The fold was clearly identified on 14 of the cadavers but was indistinct on 2 on gross examination. Beneath the fold were 2 muscle bundles. The more superficial muscle runs parallel to the fold whereas a deeper muscle runs at right angles to it. The buccal fat pad lies above the fold and appears to be retained by horizontal septae in the fat pad and also by the musculature of the fold. Cadavers showing a poorly defined nasolabial fold had fewer muscle bundles to support the fat and fewer fibrous septae running through the fat. CONCLUSIONS: The nasolabial fold is defined by structures that support the buccal fat pad and hold it above the fold. This appears to be a combination of muscle bundles that run both across and parallel to the fold and also by fibrous septae supporting the fat pad. This has implications for the development of surgical procedures to soften or eliminate the fold, which must separate the muscles from the dermis of the fold and allow the fat to descend and soften the fold.
