Does geographic tongue usually turn into a fissured tongue?

No: While both situations involve the tongue, they do not appear to be related. Fissured tongue is an anatomic variant. Geographic tongue involves desquamation or surface sloughing of the top layer of the tongue.

It can: Geographic tongue and fissured tongue are two benign conditions that often appear together, and one theory suggests fissured tongue is the end stage of geographic tongue. However, many cases of geographic tongue do not progress to fissured tongue.