FISSURED TONGUE. Tongue with multiple small furrows or grooves on the dorsal (top) surface of the tongue. These fissures can be shallow or deep, single or multiple. A small percentage of the population has it. No treatment is necessary except to encourage good oral hygiene including brushing the top surface of the tongue to remove any food debris from the fissures. Cleansing of the tongue helps prevent irritation and possible bad breath that may occur from food getting trapped in the grooves. #k