This study reports three interesting cases of nodular submucosal lip lesions where foreign-body reactions of unknown origin were detected on hematoxylin and eosin (H&E) analysis. These materials were evaluated under polarized light microscopy, scanning electron microscopy and by energy dispersive X-ray analysis. The results revealed the following materials: an interdental toothbrush bristle, silica, and iron. Unusual mucosal foreign body reaction cases have been reported, but few publications used special techniques to identify the specific foreign material. Clinicians and pathologists might consider these techniques for identifying the precise origin of these foreign bodies.586-91