Oscillations of what cause quantum waves? Electromagnetic waves are produced by oscillating electric charges. In quantum mechanics this fact is represented by photons mediating electromagnetic interactions of particles with an electric charge.
However, in quantum mechanics, any particle can be viewed as a wave. Can this wave also be viewed as caused by oscillations of some type of charges or quantum numbers?
For example, the electron can be viewed as a wave, just like the photon. So, if the electromagnetic wave that the photon represents is caused by oscillating electric charges, then oscillating of what causes the wave that the electron represents?
 A: Photons don't mediate electromagnetic interactions, Virtual photons do. They don't really exist like physical photons, they're just in mathematical formalisms. The photons emitted by accelerating charges are described by this. 
AFAIK The 'waves' of matter in QM aren't waves in the same sense, depending on your interpretation they may not be physical at all, rather just information about what can be known about the system since the last measurement. Wavefunctions in QM just describe the different observable values and the probabilities tagged to them.
Hope this helps
A: You are confusing the classical framework of Maxwell's equations with the quantum mechanical.

For example, the electron can be viewed as a wave, just like the photon. 

Both the photon and the electron are described by a wave function whose complex conjugate squared gives the probability density for the particular observation.

So, if the electromagnetic wave that the photon represents is caused by oscillating electric charges,

The photon is not an electromagnetic wave: it has a wavefunction.  The classical oscillating fields emerge from an enormous number of quantum mechanical photon fields. ( for a mathematical analysis look at this link). The reason that the photons, defined  in the quantum mechanical framework can build up the classical maxwell electromagnetic field is because their wave function is the solution of the quantized Maxwell equation..


then oscillating of what causes the wave that the electron represents?

The  wavefunctions  of electrons, positrons and the rest of massive particles in the standard model of particle physics,  are based on solutions of the Dirac equation. There exists the Schrodinger-Newton equation  studied as a limiting case but the analysis goes in a different direction, does not have the simple solutions which allow for the emergence of the classical electromagnetic field from the photon wavefunction.
Thus your wave analogy does not hold.
