THE SHAPE OF THE DENTAL ARCHES

¹ Anatomy Department, Queen's University, Belfast, Ireland

1. In fetal life, the dental lamina, enamel organs, primordial jaw cartilages, and the developing tooth-bearing bones develop in a series of similar curved catenary-like arches.

2. In postnatal life, the dental arches in many animals deviate from the early catenary form but the basal elements of the jaws remain more constant. The deviation in dental arch form is due to the nature of alveolar process growth and not to the pressure effects of the adjacent soft tissues.

3. In man, the dentition maintains the primordial catenary form because alveolar process growth does not show a regional differentiation but remains more or less equal in amount and constant in direction in all parts of the arch.