Bruxism is the involuntary grinding and clenching of teeth, often occurring unknowingly during sleep. This repetitive jaw activity can lead to tooth damage, chronic headaches, and persistent jaw pain. Occlusal splints, commonly known as night guards, are a primary non-invasive intervention designed to manage bruxism and mitigate its damaging consequences. These custom-fitted devices provide protection for dental structures and reduce the muscular symptoms associated with this habit.
What Is an Occlusal Splint?
An occlusal splint is a removable orthopedic appliance typically constructed from hard, durable acrylic resin. It is custom-fabricated by a dental laboratory using precise impressions of a patient’s teeth, ensuring a snug fit over the upper or lower dental arch. The primary function of the splint is to act as a physical barrier between the upper and lower teeth, preventing direct tooth-on-tooth contact during clenching or grinding. Unlike athletic mouthguards, the occlusal splint is specifically engineered to manage the bite relationship (occlusion) and jaw joint function. This appliance covers the entire arch, stabilizing the jaw and preventing unwanted shifting of individual teeth.
The Therapeutic Mechanism of Action
The effectiveness of an occlusal splint stems from its ability to alter the biomechanics and sensory feedback of the jaw system. The hard, flat surface eliminates the subconscious drive for jaw muscles to find a familiar, destructive “home” position. By preventing the teeth from meeting in their usual pattern, the splint essentially “deprograms” the hyperactive masticatory muscles, such as the masseter and temporalis. This normalization of muscle activity is mediated through the periodontal ligament proprioception, the sensory feedback system that signals force and position. The even, simultaneous contact across the splint surface provides stable sensory input, signaling the central nervous system to reduce the excessive muscular tension contributing to pain and grinding.
This mechanism also provides superior force distribution, which protects the teeth and existing dental restorations. The intense forces generated during bruxism, which can be several times greater than normal chewing forces, are spread evenly across the entire surface of the hard splint. This prevents concentrated stress on individual teeth, reducing the risk of fractures, excessive wear, and damage to fillings or crowns. For patients experiencing temporomandibular joint (TMJ) discomfort, certain stabilization splints promote a temporary, relaxed mandibular position. This allows the TMJ structures to rest and heal by relieving pressure on the joint capsule and associated muscles.
Key Distinctions in Splint Types
Occlusal splints are primarily categorized by their material and coverage. Custom-fitted hard acrylic splints are the gold standard for bruxism management. Hard acrylic splints, such as the Michigan or stabilization splint, offer the necessary rigidity and durability to withstand intense grinding forces. These appliances are fabricated in a dental lab, ensuring a precise, stable occlusal plane conducive to muscle relaxation. This is distinct from soft or thermoplastic “boil-and-bite” guards, which may lack the structural stability required for therapeutic efficacy.
Soft splints can sometimes function like a “chew toy,” potentially stimulating rather than inhibiting clenching reflexes and aggravating bruxism symptoms. The preferred design for bruxism is a full-coverage splint, meaning it covers all teeth in one arch. Full coverage is essential because partial-coverage splints, which only cover a segment of teeth, risk causing unintended movement or extrusion of the uncovered teeth over prolonged use. This permanent change to the natural bite relationship is an unwanted side effect that a professionally designed full-coverage splint prevents.
Patient Care and Adjustment
Using an occlusal splint requires a period of adjustment as oral tissues adapt to the new appliance. Patients may initially experience increased salivation, a natural response to a foreign object, or slight, temporary changes in speech patterns. The splint may feel bulky for the first few nights, but consistent nightly use is necessary for the masticatory system to adapt to the new, relaxed jaw position. This initial adjustment typically resolves within a few days to a couple of weeks of compliant wear.
Proper maintenance is necessary to ensure the splint’s longevity and prevent bacterial accumulation. The appliance should be cleaned daily with a soft-bristled brush and a mild, non-abrasive cleanser, such as a specialized denture cleaner or gentle hand soap. Regular toothpaste must be avoided because its abrasive particles can create microscopic scratches in the acrylic surface, which harbor bacterial growth. The splint must be stored in its ventilated case, sometimes kept moist, and shielded from heat to prevent warping or distortion of the custom fit. Routine dental check-ups allow the dentist to assess the splint for wear, check the fit, and make minor adjustments needed to maintain therapeutic efficacy.