Typing Lehners classification minor aphthous ulcer (MIAU) major aphthous ulcer (mau) herpetiform ulcer (Hu) ● Characteristic recidivity self-healing periodicity NEXT• Typing Lehner’s classification minor aphthous ulcer （MiAU） major aphthous ulcer （MjAU） herpetiform ulcer （HU） • Characteristic recidivity self-healing periodicity NEXT