Taking a dynamical systems approach to GT enabled us to classify the severity of the condition, based on the patterns observed on the tongue of a GT patient. Typically GT-affected tongues fall into two main categories. The first corresponds to oblate patterns that expands and merges with other growing oblate regions. In this case, like with forest fires, the tongue is gradually affected but then subsequently heals. Another more “exotic” form of the condition involves patterns consisting of open-ended tips, most notably spirals, which can evolve into the recovering regions of the tongue.