When examining a night guard (occlusal splint) from a bruxism patient, what is the characteristic finding that confirms heavy parafunctional activity?

The characteristic finding on a night guard from a bruxism patient is the presence of smooth, highly polished wear facets on the occlusal surface. These result from the repetitive, forceful grinding and lateral sliding movements characteristic of bruxism. The smooth, glossy surfaces occur because the hard acrylic is progressively worn away by sustained tooth contact. These wear patterns also help identify the functional excursive pathways used during bruxism. In contrast, normal occlusal contact patterns produce small, distinct contact markings. Cracks may occur in severe cases but smooth wear facets are the hallmark finding. The distribution and depth of wear facets guide adjustment of the appliance.