A novel system for discerning pressure points in mouthpieces, namely orthodontic aligners. The system includes the steps of applying a colored gel to a light transmissive or clear mouthpiece-type aligner, mounting the aligner to the upper and/or lower teeth of the patient, and observing through the mouthpiece color variations generated by variations in gel density, wherein pressure points are indicated as lighter colors due to less gel density and spaces are indicated as deeper color, due to higher density of the colored gel. In an alternative embodiment a second gel incorporating rupturable spheres incorporating a second composition is utilized in the present system such that pressure upon the gel releases the second composition, which would be formulated to combine with the first gel and result in a color change, either due to a chemical reaction, or due to a mixing of two colors to produce an identifying color.