Heirs of box types in polynomially bounded structures

We characterize heirs of so called box types of a polynomially bounded o-minimal structure M. A box type is an n-type of M which is uniquely determined by the projections to the coordinate axes. From this, we deduce various structure theorems for subsets of Mk, definable in the expansion M* of M by all convex subsets of the line. Moreover we obtain a model completeness result for M*