A microelectromechanical mirror device , comprising: a fixed structure defining a cavity ; a tiltable structure carrying a reflecting surface , elastically suspended above the cavity and having a main extension in a horizontal plane (xy); at least one first pair of driving arms , elastically coupled to the tiltable structure and carrying respective piezoelectric material regions configured to be biased to cause a rotation of the tiltable structure around at least one first rotation axis (X) parallel to a first horizontal axis (x) of said horizontal plane (xy); elastic suspension elements , configured to couple said tiltable structure elastically to said fixed structure at said first rotation axis (X), stiff with respect to movements out of the horizontal plane (xy) and yielding with respect to torsion around said first rotation axis (X), said elastic suspension elements extending between said tiltable structure and said fixed structure ; and a piezoresistive sensor , configured to provide a detection signal associated with the rotation of the tiltable structure around the first rotation axis (X), wherein said elastic suspension elements comprise a first and a second elastic suspension element, coupled to said tiltable structure on opposite sides along said first horizontal axis (x); wherein said first elastic suspension element is formed with a first torsional stiffness and said second elastic suspension element is formed with a second torsional stiffness, characterised in that said second torsional stiffness is different from said first torsional stiffness; and in that said piezoresistive sensor is arranged in the proximity of the elastic suspension element, between the first and the second elastic suspension elements , having a higher torsional stiffness. a fixed structure defining a cavity ; a tiltable structure carrying a reflecting surface , elastically suspended above the cavity and having a main extension in a horizontal plane (xy); at least one first pair of driving arms , elastically coupled to the tiltable structure and carrying respective piezoelectric material regions configured to be biased to cause a rotation of the tiltable structure around at least one first rotation axis (X) parallel to a first horizontal axis (x) of said horizontal plane (xy); elastic suspension elements , configured to couple said tiltable structure elastically to said fixed structure at said first rotation axis (X), stiff with respect to movements out of the horizontal plane (xy) and yielding with respect to torsion around said first rotation axis (X), said elastic suspension elements extending between said tiltable structure and said fixed structure ; and a piezoresistive sensor , configured to provide a detection signal associated with the rotation of the tiltable structure around the first rotation axis (X), wherein said elastic suspension elements comprise a first and a second elastic suspension element, coupled to said tiltable structure on opposite sides along said first horizontal axis (x); wherein said first elastic suspension element is formed with a first torsional stiffness and said second elastic suspension element is formed with a second torsional stiffness, characterised in that said second torsional stiffness is different from said first torsional stiffness; and in that said piezoresistive sensor is arranged in the proximity of the elastic suspension element, between the first and the second elastic suspension elements , having a higher torsional stiffness. <EOS>