Complex sentence: The treatment is also often dependent upon whether the bruxism happens during sleep or while awake, e.g., an occlusal splint worn during sleep in a person who only bruxes when they are awake will probably have no benefit.
Split into simpler sentences: The treatment is also often dependent upon whether the bruxism happens during sleep or while awake. E.g., an occlusal splint worn during sleep in a person who only bruxes when they are awake will probably have no benefit.