Continuous Improvement of Frontal Rhytids Following Glabella Only Treatments With Neuromodulators-A Clinical Prospective Pilot Study

Abstract

Introduction: While traditionally focused on treating glabellar and forehead rhytids through direct neuromodulator injections, recent findings on the biomechanics of facial muscles suggest that glabellar treatments alone may influence forehead wrinkles by altering the dynamic balance between depressor and elevator muscles.

Objective: To evaluate whether glabellar-only neuromodulator treatments can reduce forehead wrinkle severity without direct injections into the frontalis muscle.

Methods: This prospective, interventional study included 18 participants with moderate to very severe glabellar lines. Neuromodulator (AbobotulinumtoxinA; 37.5 sU (= 15 IU)) injections were administered exclusively in the glabella at three intervals over 7 months. Glabellar Severity Scale (GLSS), Forehead Wrinkle Scale (FWS), Frontal Skin Displacement (FSD), and Eyebrow Position Scoring (EPS) were assessed at baseline and 30 days after each cycle.

Results: GLSS scores significantly improved across treatment cycles (baseline: 3.0; post-third cycle: 1.0; p < 0.001). FWS improved from 3.0 at baseline to 1.0 after the third cycle (p = 0.005), while FSD showed a significant reduction from 37.2 mm to 17.9 mm (p < 0.01). No changes in eyebrow position were detected following EPS assessment.

Conclusion: Glabellar-only neuromodulator treatments with 37.5 sU (= 15 IU) effectively reduced forehead rhytid severity, likely by altering the balance between depressor and elevator muscles. This approach minimizes risks associated with direct frontalis injections and offers a novel strategy for forehead rejuvenation. Moreover, the observed progressive improvement across treatment cycles suggests that this strategy may continuously enhance aesthetic outcomes over time, supporting the rationale for maintenance treatments at regular intervals.

Keywords: facial aesthetics; facial biomechanics; forehead lines; glabellar lines; neuromodulator treatments.

FIGURE 1

Timeline and structure of the study showing the treatment and evaluation cycles. Neuromodulator injections were administered in the glabellar region on Day 0, 90, and 180. Post‐treatment evaluations were conducted 30 days after each cycle on days 30, 120, and 210, respectively. EES, Eyebrow Elevation Scale; FSD, frontal skin displacement; FWS, Frontal Wrinkle Scale; GAIS, Global Aesthetic Improvement Scale; GLSS, Glabellar Severity Scale.

FIGURE 2

Representation of the conducted 3‐point injection technique used for glabellar treatment. sU, Speywood units.

FIGURE 3

Frontal Skin Displacement Assessment Using 3D Imaging. Arrows represent the direction and magnitude of skin displacement, with reddish arrows indicating higher displacement values on a scale ranging from 0 to 5 mm.

FIGURE 4

Sequential images of a 42‐year‐old male participant during maximal glabellar contraction. The figure illustrates the progression of wrinkle severity as evaluated by the Glabellar Severity Scale (GLSS) at all treatment (Day 0, 90, and 180) and post‐treatment (Day 30, 120, and 210) endpoints. p‐values indicate differences across post‐treatment groups according to the Wilcoxon signed rank test.

FIGURE 5

Bar graphs showing the median and interquartile range (IQR) of the Glabella Severity Scale (GLSS) at all treatment (Day 0, 90, and 180) and post‐treatment (Day 30, 120, and 210) endpoints. p‐values indicate across‐group differences according to the Kruskal–Wallis test.

FIGURE 6

Sequential images of a 37‐year‐old female participant during maximal eyebrow elevation. The figure illustrates changes in forehead lines at all treatment (Day 0, 90, and 180) and post‐treatment (Day 30, 120, and 210) endpoints. Markers aligned with the eyebrow indicate variations in eyebrow elevation across time points.

FIGURE 7

Sequential images of a 35‐year‐old female participant during maximal eyebrow elevation. The figure illustrates changes in forehead lines at all treatment (Day 0, 90, and 180) and post‐treatment (Day 30, 120, and 210) endpoints. Markers aligned with the eyebrow indicate variations in eyebrow elevation across time points.

FIGURE 8

Sequential images of a 46‐year‐old female participant during maximal eyebrow elevation. The figure illustrates changes in forehead lines at all treatment (Day 0, 90, and 180) and post‐treatment (Day 30, 120, and 210) endpoints. Markers aligned with the eyebrow indicate variations in eyebrow elevation across time points.

FIGURE 9

Bar graphs showing the median and interquartile range (IQR) of the Frontal Wrinkle Scale (FWS) at all treatment (Day 0, 90, and 180) and post‐treatment (Day 30, 120, and 210) endpoints. p‐values indicate across‐group differences according to Kruskal–Wallis test.

FIGURE 10

Bar graphs showing the mean and standard deviation (SD) of the Frontal Skin Displacement (FSD) at all treatment (Day 0, 90, and 180) and post‐treatment (Day 30, 120, and 210) endpoints. p‐values indicate across‐group differences according to Kruskal–Wallis test.