Although PMMA has for decades proven itself as a denture base material, there has been a continual search for other solutions. The concern was with reducing residual monomer and finding chemical alternatives for the few true allergy sufferers and the many monomer-phobics. Semicrystalline polymers then offered the possibility to fabricate acrylic brackets which, in turn, provided a true alternative for metallophobics and allergy sufferers, as well as those with high aesthetic expectations. The elasticity of some of these acrylics also provides treatment with removable dentures for patients of microstomia. The ancient theorem that "noticeably elastic denture bases would lead to increased jawbone resorption" has not yet been proved, but there are indications that the opposite could be true.