Chapter provides an in-depth analysis of tooth wear, presenting it as a fundamental physiological and functional adaptation in the evolution of mammals—particularly humans. Rather than being viewed as mere tissue loss, dental wear is described as a necessary process for occlusal maturation, stomatognathic function, and efficient mastication. The chapter explains how wear allows teeth to progressively adapt to masticatory forces, improving force distribution, shaping functional occlusal surfaces, and supporting the biomechanical development of the entire oral system. It distinguishes physiological from pathological wear and discusses the dietary changes in human history, from prehistoric to industrial times. In the past, the natural abrasiveness of food ensured consistent wear, which prevented many modern occlusal problems such as crowding and malocclusion. The text also explores the structural levels of dental enamel—millimetric, micrometric, and nanometric—demonstrating how its hierarchical organization provides fracture resistance, adaptability, and long-term functionality. The evolution of prismatic enamel in mammals is highlighted as a biomechanical breakthrough. Finally, the importance of both interproximal and occlusal wear is emphasized in shaping human facial structure and preventing modern dental pathologies, supported by paleoanthropological evidence and current clinical data. Dental wear, rather than being a destructive process, is reframed as an evolutionarily advantageous phenomenon that has shaped the function and form of human dentition.