The open string sector of the topological B-model model on CY (m + 2)-folds is described by m-graded quivers with superpotentials. This correspondence extends to general m the well known connection between CY (m + 2)-folds and gauge theories on the worldvolume of D(5 − 2m)-branes for m = 0, . . . , 3. We introduce mdimers, which fully encode the m-graded quivers and their superpotentials, in the case in which the CY (m+2)-folds are toric. Generalizing the well known m = 1, 2 cases, mdimers significantly simplify the connection between geometry and m-graded quivers.A key result of this paper is the generalization of the concept of perfect matching, which plays a central role in this map, to arbitrary m. We also introduce a simplified algorithm for the computation of perfect matchings, which generalizes the Kasteleyn matrix approach to any m. We illustrate these new tools with a few infinite families of CY singularities. arXiv:1904.07954v1 [hep-th] 16 Apr 2019 9 Chiral cycles and perfect matchings for Y 1,0 (P m ) 35 9.1 Chiral cycles and the moduli space 37 -i -10 Orbifolds of C m+2 39 10.1 Orbifolds of C m+2 with SU (m + 2) global symmetry 43 11 Conclusions 44 A Perfect matchings for F (m) 0 46 B Perfect matchings for general orbifolds of C m+2 483 The framework of m-graded quivers can be extended to theories with gauge groups that are not unitary and with fields that do not transform in the bifundamental or adjoint representations, i.e. theories that are not of quiver type. We will not consider these possibilities in this paper. 4 The range of degrees in (2.3) is just a conventional choice. The n c "fundamental" degrees can be picked differently. Moreover, as we will later illustrate in examples, sometimes it is convenient to deal with all possible values of the degrees. For every arrow, either Φ (c) ij or Φ (m−c) jican be regarded as the fundamental object, while the other one is its conjugate.