Total Composite Flap Facelift and the Deep-Plane Transition Zone: A Critical Consideration in SMAS-Release Midface Lifting

Recent anatomic studies suggest the superficial musculoaponeurotic system (SMAS) layer attenuates in the midface. This led the author to switch from a bilamellar high SMAS dissection to a "total composite flap" technique, preserving skin and SMAS/platysma as one layer in a critical "deep-plane transition zone" (DTZ) lateral to the zygomaticus major muscle. This allows traction on the SMAS to translate to the malar fat pad via a "cantilever bridge" effect, which is lost when skin is undermined in the DTZ. This paper attempts to answer the question of whether the composite flap or bilamellar technique better lifts the midface, comparing groups where the DTZ was undermined: (1) only at a sub-SMAS level; or (2) at both subcutaneous and sub-SMAS levels. Thirty-five patients underwent bilamellar facelifts with skin and SMAS separated in the DTZ. Midfacial elevation was measured using size-matched preoperative and 18-month (average) postoperative photographs for the 70 hemi-midfaces. The same analysis was done for 35 patients undergoing total composite flap facelift, maintaining skin and SMAS as one layer in the DTZ. The two groups were compared. In the bilamellar group, the mean percentage of midfacial elevation at 18 months postoperative was 5.5% (range, 0.0%-17.8%). In the composite flap group, the percentage was 11.7% (range, 0.1%-32.3%). The difference was statistically significant. Maintaining skin-SMAS attachments in the DTZ improves midface elevation during SMAS facelifting, exploiting a "cantilever bridge" effect of the skin transferring traction on the SMAS to the malar fat pad. Therapeutic.