<p>The effects of tooth modification and deviations on gear transmission are generally interpreted in terms of altered local contact characteristics and contact ratio. However, these factors may also introduce minor interference between meshing teeth, resulting in asynchronous contact phenomena that have received limited attention in gear dynamics. This study investigates the effects of this phenomenon via surface gap modeling and dynamic analysis. A discrete-surface representation extends the model to arbitrary gear geometries. Finite element analysis validates that tooth contact can show significant changes under interference caused by misalignment. A modified dynamic model incorporates pre-coupled meshing parameters and applies to both spur and bevel gears. Based on this model, the interference effect is isolated by comparing the nominal state with a forced synchronous condition. Results indicate that minor interference can smooth load transfer, reduce abrupt stiffness changes, and suppress high-frequency vibration. Importantly, this study shows that inter-tooth interference induced by profile adjustments can also play a crucial role in gear contact evolution and meshing stability, in addition to the effects of local contact geometry commonly considered in conventional analyses.</p>