Structure and function is a useful starting point for the consideration of factors affecting the mouth. This chapter provides a definition of what we mean by oral health. There follows some background information on the development of the teeth and a description of tooth types, their structures and the numbering systems used to describe them. The chapter continues with an overview of saliva, which plays an essential role in the oral environment. Finally, dental plaque is described.

Oral Health

Oral health is achieved when the teeth and oral environment are not only healthy but also:

• comfortable and functional, that is food can be chewed thoroughly and without pain or discomfort and the teeth are not sensitive to different stimuli such as cold


• social acceptability is also of importance and the mouth must not give rise to bad breath, the appearance of the teeth and gums should be acceptable and not give rise to embarrassment


• there should be an absence of sources of infection which may affect general health

This state of oral health should persist for life, which given a healthy lifestyle, is achievable for the majority of the population.