What it means for a patient
- Almost every patient had temporary numbness or tingling after surgery.
- Folliculitis, inflammation of the hair follicles, occurred in about a quarter of patients.
- Visible scarring, fluid collection, hair loss at the incision and revision surgery were each uncommon.
- Nearly every patient reported being satisfied.
- Limits: most included studies were retrospective case series, and the overall complication rate varied widely between studies.
Why this paper matters
It pooled complication rates and satisfaction for forehead reduction surgery across 14 published studies.
Overview
Forehead reduction surgery shortens a tall forehead by moving the hairline down, and it is performed more and more often to improve facial balance. It is generally considered safe, but its complication rates had not been measured across studies. The authors ran a systematic review and proportional meta-analysis following PRISMA guidelines.
Findings
- Databases searched through August 2025: MEDLINE, Embase, Cochrane, Web of Science and ClinicalTrials.gov.
- Included studies had at least 10 adult patients and reported at least one complication.
- Risk of bias was assessed with Joanna Briggs Institute checklists.
- 14 studies, 3,213 patients, mostly female, aged 16 to 76.
- Most studies were retrospective case series; 1 was a prospective cohort and 1 a cross-sectional study.
- Pooled overall complication rate: 5.9% (95% CI 3.2 to 10.7%; I² = 92.4%).
- Scarring: 5.5%. Seroma: 2.4%. Folliculitis: 25.1%.
- Hair loss at the incision: 0.7% (0.3% after sensitivity analysis).
- Temporary paresthesia: 97.3%.
- Later hair transplantation: 1.2%. Revision surgery: 1.3%.
- Patient satisfaction: 99.9% (I² = 6.1%).
- The authors call for standard outcome definitions, validated patient-reported outcome measures and more diverse study populations.
Terms
- Forehead reduction surgery: an operation that lowers the hairline to shorten the forehead; also called hairline lowering.
- Systematic review: a search of all published studies on a question using set rules.
- Meta-analysis: a statistical method that combines results from several studies.
- PRISMA: a standard checklist for reporting systematic reviews.
- Seroma: a pocket of clear fluid that collects under the skin after surgery.
- Folliculitis: inflammation of hair follicles.
- Paresthesia: tingling, prickling or numbness of the skin.
- Alopecia: hair loss.
- Heterogeneity (I²): a measure of how much results differ between studies; higher means more difference.
- Confidence interval (CI): the range in which the true value likely falls.