Oral lichen planus is a chronic inflammatory and immune-mediated disease that affects the oral mucosa. Recent findings have suggested that oral lichen planus is often associated with submucosal fibrotic changes. Fibrotic changes in the buccal submucosa may cause restricted mouth opening. This report discusses the histopathological examination (including specialized staining) and surgical treatment for oral lichen planus-induced fibrotic changes. Our findings suggest that histopathological examination with specialized staining can aid in the evaluation of oral lichen planus-induced fibrotic changes, and that Z-plasty is effective for the treatment of restricted mouth opening due to ora...