You could use a Maestro with two regular 3-way switches for turning it on and off, but they will not do dimming as Dennis has already mentioned. The two 3-ways would need to form a switch loop that connects: 1.) the brass screw of the Maestro that supplies the load, and 2.) the blue screw of the Maestro.
See the second wiring diagram on page 4 of this Lutron document:
They are using only two screws of a 3-way mechanical switch and so it's just working as a single-pole single-throw switch between the brass and blue screws of the Maestro. Therefore two 3-ways switches in a switch loop can be substituted for this single switch so that the light is controlled from three locations (the Maestro dimmer and each 3-way).
As indicated on Note 1 on the bottom of page 1 of the document, a programming step is needed before using the Maestro with mechanical switches. I think this is because the companion dimmers turn it on and off using momentary contacts, but the mechanical switches will sustain a connection in each switch position.