Self-gravitational modes in dusty plasmas have been extensively studied for both extreme cases of wave propagation: waves propagating parallel to an external magnetic field and perpendicularly propagating waves. Provided the presence of neutral is insignificant, the presence of charged dust species stabilizes plasmas against gravitational collapse, the mechanisms being induced by plasma thermal effects and/or magnetic field pressure. We present here the modifications of magnetosonic modes and electrostatic, parallel modes due to the possible distributions of the dust mass. The necessary adaptations of the corresponding critical Jeans lengths are discussed and extended to intermediate angles of propagation. ©2000 American Institute of Physics.