  Optically thin dusty disks around Main Sequence stars consist of debris from
catastrophic collisions or from low erosion of long-lived planetesimals.
Resolved observations of dusty disks have systematically evidenced asymmetries
and annular structures. It has been proposed that some of these structures
could be signatures of undetected exoplanets. In this paper, I review and
discuss currently proposed models to account for the observed structures. These
include the impact of distant exoplanets and/or of stellar companions. The
Solar System serves as a reference case for these approaches and similarities
are pointed out along the paper as well as some limitations of current modeling
efforts.
