What is the difference between a night guard and a sleep appliance?

The clinical distinction matters most at prescription time. A night guard, whether hard acrylic, dual-laminate, or soft vinyl, is designed for occlusal protection. Bite force from parafunctional grinding can exceed 200 lbs per square inch, and the guard absorbs and distributes that load across the arch. Fit precision matters here: a poorly adapted guard shifts occlusion and creates its own joint symptoms.

A sleep appliance, such as an EMA, Herbst, or dorsal-fin design, works on a different mechanism entirely. It advances the mandible 50 to 75 percent of maximum protrusion, which enlarges the pharyngeal airspace and reduces airway collapse during sleep. The lab prescription must include a protrusive bite registration, and the titration range built into the device determines how far the clinician can adjust post-delivery without remaking the appliance.

For general dentists managing patients with dual diagnoses, bruxism and sleep-disordered breathing together, the prescribing decision has real clinical stakes. Some combination devices exist, but the evidence base for dual-function appliances is narrower. Most prosthodontists and sleep medicine physicians recommend separate appliances optimized for each function. A lab with both fabrication workflows in-house, rather than outsourcing one of them, keeps turnaround consistent and communication on one channel.