Fig. 4.

The dependence of the absorption of THz radiation in terms of $\log \frac{{\mathrm{I}}_c}{{\mathrm{I}}_b}$ on the frequency for (c) the control group, (a) patients with erosive OLP, and (b) reticular and papular OLP. The confidence intervals are shown. Here, $I_{\mathrm{b}}$ and $I_{\mathrm{c}}$ are the output intensities of THz radiation that passed through parts “b” and “c” of the cuvette, respectively (see Fig. 2).