TRACE ELEMENT ANALYSIS OF THE ORAL MUCOSA OF 22 PATIENTS WITH ORAL LICHEN PLANUS BY THE PIXE METHOD

We made a comparative study of the trace elements in the oral mucosa of 22 patients with oral lichen planus (OLP) and of 100 healthy persons by the PIXE method. Samples were excised from the oral mucosa of the OLP patients (OLP group) and from the buccal mucosa of healthy persons (control group). The results were as follows: Seventeen trace elements and 11 contaminating elements were detected in those oral mucosae. Al, Ti and Pb, which are contaminating elements, were detected in more than 65% of samples from both groups. The mean values of Se and Rb were significantly lower in the OLP group than in the control group. The mean values of the other elements did not differ significantly between the groups. As for the females over 30 years old, the OLP group showed significantly higher values of Zn and Sr than the control group. Their mean values of the other essential and contaminating elements did not differ significantly between the groups, although there was a trend toward higher values in the OLP group. We found by the PIXE method that Zn, Fe and Pd, which are d-transitional elements considered to cause allergic reaction, showed higher values in the oral mucosae of the OLP patients than in those of the healthy persons.