Human deciduous and permanent teeth have pulpal tissue within the dentine of their crowns and roots. Crown dentine is covered by enamel, root dentine by cementum. The periodontal ligament attaches the cementum to the alveolar bone in which the tooth lies. Gingivae surround the crown where it projects into the mouth. The pulp periodontal and gingival tissues have a blood and nerve supply. In craniofacial and dentofacial development the neural crest has a major inductive role, giving origin to ectomesenchyme which migrates to form neural skeletal and connective tissue derivatives (Le Douarin 1982, 1984).