[OI] fluxes at 63 μm versus WISE flux at 22 μm: observations compared to models. The contours show the density of points for models from the DENT grid. Black dots show the position of observed Class II sources, red pentagons are transitional discs, and grey triangles are HAeBe stars. The top panel shows the whole distribution of selected models. The middle panel shows the distribution of models with f_UV = 0.1, while the bottom panel shows models with f_UV = 0.001. The arrows point to the location of sources with different values of β. The solid line is a linear fit to the observed data.