Optimal Facelift Vector and its Relation to Zygomaticus Major Orientation

Area of Science:

• Plastic Surgery
• Anatomy
• Facial Aesthetics

Background:

• The vector of the superficial musculoaponeurotic system (SMAS) in rhytidectomy is often related to the zygomaticus major muscle (ZMM) to prevent distortion.
• Current literature lacks data on the true orientation of the ZMM in the midface.

Purpose of the Study:

• To define the vector of the ZMM in relation to the Frankfort horizontal plane.
• To provide anatomical data for improved rhytidectomy techniques.

Main Methods:

• Measurement of the ZMM orientation as an angle relative to the Frankfort horizontal plane.
• Data collected from 100 patients undergoing deep plane rhytidectomy (200 hemifaces).

Main Results:

• The average ZMM angle was 59° (SD 6°, range 41-72°) relative to the Frankfort horizontal plane.
• A statistically significant age-related pattern was observed: more acute angles below 60 years and more obtuse angles above 60 years.

Conclusions:

• The native ZMM vector shows significant variability among patients.
• Standard SMAS redraping vectors may need reconsideration; customized vectors are advised.
• Aging impacts ZMM orientation due to soft tissue and bony changes, increasing individual variability.