Quantitative Assessment of Closure Forces in Paramedian Forehead Flap Donor Sites

Paramedian forehead flap (PMFF) reconstruction remains the gold standard for complex nasal defects, but donor site closure under tension risks dehiscence and poor scarring. This study quantifies closure forces for PMFF donor sites and evaluates force reduction achieved with coronal advancement flaps.

Fifteen fresh cadaveric specimens were randomized to 3 groups based on the flap width (1.5, 3, or 4.5 cm). Using a 6-degree-of-freedom robotic system, forces required for primary closure, hemicoronal advancement, and bicoronal advancement were measured. Force comparisons across closure techniques were analyzed using the Friedman test with post hoc Wilcoxon signed-rank tests.

Primary closure forces averaged 9.1±0.4N, 29.0±4.2N, and 47.3±6.8N for 1.5, 3, and 4.5 cm defects, respectively. Suture failure occurred in 80% of 4.5 cm defects before achieving primary closure. Hemicoronal advancement reduced forces by 42% to 64%, and bicoronal advancement reduced forces by 77% to 86% compared with primary closure. Friedman analysis confirmed significant differences in closure forces across techniques (χ²=10.0, P =0.0067), while Wilcoxon pairwise comparisons showed consistent trends toward lower forces with advancement flaps, though not statistically significant due to small sample size.

Coronal advancement flaps provide a substantial biomechanical advantage for PMFF donor site closure. Statistical analysis supports observed trends of tension reduction, reinforcing the clinical benefit of hemicoronal and bicoronal flaps for moderate to large defects.