Targeting the Perialar Space for Enhanced Nasolabial Fold Rejuvenation: A Cadaveric Study

Nasolabial folds, or "smile lines," result from the interaction of several anatomical structures, including the levator labii superioris alaeque nasi and the zygomaticus major and minor muscles, which place continuous tension on the dermis. Although the deep pyriform space is a common target for treating these folds, filler migration from this space can cause undesirable outcomes.

To examine the anatomical characteristics and potential benefits of using a newly identified medial space: the perialar space, adjacent to the deep pyriform space, for nasolabial fold volumization to facilitate more effective and stable filler placement.

Twenty-two fresh cadavers were used (44 hemifaces: 13 male, 9 female; mean age 81.98 years) without trauma, surgery, or major deformities. Dyed injectate was administered into the deep pyriform and perialar spaces. Cannula resistance during insertion was measured, and injectate distribution was assessed through comprehensive dissection.

The mean forces at the first and second puncture sites were 1.70 ± 0.58 N and 3.29 ± 1.35 N, respectively. Dissection confirmed injectate placement in a space adjacent to, but distinct from, the deep pyriform space. Statistical analysis showed significant differences in tissue resistance between sites (p < 0.05). The perialar space thus represents a useful alternative for nasolabial fold volumization. Histological evaluation confirmed distinct boundaries, supporting its suitability as a stable and reliable site for filler injection.

This study shows the potential of the perialar space for enhancing aesthetic outcomes; reducing complications and filler migration; and achieving more stable enhancements in facial rejuvenation procedures than existing techniques.