Top: comparison between the position angle of the mid-infrared emission from the parsec-scale structure (PA_MIR) and the inferred position angle of the system polar axis (PA_polar) for the elongated objects. For completeness we also include the marginally elongated object NGC 4507 (blue triangle), no error bars are determined for this object. The dashed line represents a one-to-one relation for the position angles. Bottom: histogram of the difference between the inferred system polar axis and the mid-infrared position angle obtained using interferometry. The histogram including the marginally elongated object NGC 4507 is shown in blue bars, while elongated objects are indicated with black bars. Only objects with elongations obtained from interferometric data have been used here.