This work studies the effects of tooth profile modification on multimesh gearset vibration. The nonlinear analytical model considers the dynamic load distribution between the individual gear teeth and the influence of variable mesh stiffnesses, profile modifications, and contact loss. The proposed model yields better agreement than two existing models when compared against nonlinear gear dynamics from a finite element/contact mechanics benchmark. These comparisons are made for different loads, profile modifications, and bearing stiffness conditions. This model captures the total and partial contact losses demonstrated by finite element. Perturbation analysis based on the proposed model finds approximate frequency response solutions for the case of no total contact loss due to the optimized system parameters. The closed-form solution is compared with numerical integration and provides guidance for optimizing mesh phasing, contact ratios, and profile modification magnitude and length.