Method
- Anatomic and histologic study on 20 fresh cadaver specimens (40 half-heads).
- Gross dissection plus histology to study the tissue layers around the eyebrow.
Findings
- The lateral eyebrow segment becomes ptotic earlier than the medial segment.
- Three fat compartments promote lateral brow descent: the galea fat pad, the preseptal fat pad, and the subgalea fat pad glide plane space.
- Three forces act on the lateral eyebrow: frontalis muscle resting tone (which suspends the medial brow), gravity pulling tissue over the temporalis fascia, and corrugator supercilii and lateral orbicularis oculi activity that can antagonize the frontalis muscle.
- The temporal fusion line of the skull, near the superior orbital rim, is identified as the axis point for these forces.
What it means for a patient
- This explains why brow sagging with age is usually worse on the outer part of the eyebrow than the inner part.
- The anatomic findings here are described as informing how forehead lift surgery is planned and performed.
- This is a cadaver anatomy study, not a clinical outcomes study.
Citations
PubMed https://pubmed.ncbi.nlm.nih.gov/8643714/.
Terms
- Ptosis (brow): downward sagging position.
- Frontalis muscle: the forehead muscle that raises the eyebrows.
- Corrugator supercilii: the muscle that pulls the eyebrows together and down, forming frown lines.
- Orbicularis oculi: the muscle that closes the eyelids and surrounds the eye.