The tooth, along with the periodontium, temporomandibular joint, larynx and pharynx, have been considered to reflect specialized or characteristic features of sensory innervation that differ from those already outlined for skin and mucosa. For example, the tooth is considered by many to be the only sensory site in the body from which the only sensation experienced is pain. The periodontium contains receptors involved in a multiplicity of oral-facial functions, while the sensory innervation of the temporomandibular joint provides a basis for monitoring jaw position, a function not carried out by other oral-facial receptors, except perhaps, those in muscle and ligaments (see chapter 8). These sensory sites in addition to, or by virtue of, these characteristics are particularly important in clinical dentistry since their sensory and reflex functions influence considerably the practice of dentistry and its specialities. The roles of these sites in oral-facial reflexes are indicated separately in chapter 9. In this chapter, consideration is given to the sensory function of the tooth pulp and dentine. The next two chapters deal with this function in the periodontium and temporomandibular joint (chapter 6) and in pharynx and larynx (chapter 7).