During development, the teeth, jaws and facial structures emerge in a process that has the characteristics of a complex adaptive system (CAS). The outcome is the mature stomatognathic system which is an interactive network of teeth, their occlusion and supporting mechanisms, the upper and lower jaws, the temporomandibular (jaw) joints, the muscles, the blood and nerve supplies, and the salivary glands. The aim of this paper is to explore whether this mature network also demonstrates the characteristics of a CAS. This network is a carefully balanced mechanism with functions required throughout the lifespan of the individual. It is exposed to a series of mechanical and chemical environmental challenges. Tooth wear is an example of the impact of such challenges, resulting in loss of surface enamel and dentine. The response is spread through the network: reparative secondary dentine occurs on the inner pulpal walls of the tooth; secondary cementum is formed and bone remodelling occurs in the suspensory mechanism; and the masticatory pattern of dental occlusion adapt under neuromuscular control. These adaptive changes arise from interactions at molecular and cellular levels. They are evidence of ongoing emergence and robustness in the network as it functions. Considering these changes to be positive responses that enable both maintenance of function and adaptation to age changes in the component parts of the network, represents a paradigm shift. It has major implications for oral health teaching and clinical practice. Attempting to restore teeth to the size and detailed cuspal shape, they showed when they first erupted is not only unnecessary for late adult function but can also place excessive loads on other subnetworks such as on the jaw joints and muscles. Thus, appreciating that both the developmental and mature stomatognathic networks are CAS establishes their value as exemplars for biological systems in general and has important implications for enhancing health care.
caries, craniofacial, dental, dentine, enamel, erosion, oral health, phenomics, tooth wear
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