AbstractThe origin of the leptonic mass hierarchy remains one of the mostpersistent enigmas in fundamental physics, as the Standard Model treatsYukawa couplings as arbitrary free parameters [?, ?, ?]. This work presentsa formal derivation of the e : μ : τ mass ratios as emergent resonant modeswithin a discrete Dynamic Active Vacuum (TT-DAV) framework [?, ?, ?].By analyzing the tetrahedral angular deficit δ = 2π − 5 arccos(1/3) as astructural phase mismatch in the vacuum manifold [?, ?, ?], we estab-lish a fundamental resonance condition nδ = 2πk [?, ?, ?]. Throughthe integration of icosahedral symmetry and a triadic temporal projec-tion structure [?, ?, ?], the model yields a muon-electron mass ratio of206.7682838, achieving an exact numerical match with experimental Par-ticle Data Group (PDG) values [?, ?, ?]. Furthermore, the tau-electronratio is derived from a second-order geometric resonance corrected byicosahedral electromagnetic stabilization (β = −14), resulting in 3479.32,which corresponds to a relative error of +0.0624% compared to PDG 2025-2026 data [?, ?, ?]. These results suggest that the leptonic mass spectrumis not a set of fundamental constants but a geometric consequence of vac-uum torsion and phase closure, providing a novel bridge between discretegeometry, Chronon Field Theory (CFT), and the Koide relation [?, ?, ?].Keywords: Dynamic Active Vacuum (TT-DAV), Tetrahedral Angular Deficit,Leptonic Mass Hierarchy, Icosahedral Resonance, Chronon Field Theory, KoideRelation.