| Field | Value |
|---|---|
| ID | OA-0164 |
| Type | occlusal |
| Category | occlusal |
| Fixed/removable | removable |
| Primary function | bruxism protection; TMD; centric relation stabilization |
| Malocclusion target | bruxism; TMD; myofascial pain; occlusal dysfunction |
| Inventor | Ramfjord & Ash (Michigan Splint); various |
| First year | 1960s |
| Period | historical / current |
| Status | current |
| Material | hard PMMA acrylic |
| Uses TADs | no |
The occlusal splint (Michigan splint, stabilization splint, flat-plane splint) is the gold standard TMD appliance — a full-coverage hard acrylic removable appliance worn at night that covers all upper teeth and provides even bilateral centric relation stops with anterior guidance. Evidence from RCTs and systematic reviews supports its use for myofascial TMD pain, bruxism, and condylar decompression. The flat posterior surface distributes parafunctional forces evenly. The anterior guidance incline disarticulates the posterior teeth on protrusion and lateral excursion (immediate posterior disocclusion), reducing lateral shear forces.
Hard acrylic provides a stable, adjustable surface for centric relation occlusion. Even posterior contacts at centric relation reduce asymmetric loading. Anterior guidance (30–45°) immediately disoccluds posterior teeth as the mandible moves from centric — this reduces masseter and temporalis elevator muscle activity during bruxism. Over months of wear, reduced muscle hyperactivity leads to reduced pain and improved TMD symptoms. The appliance does not cure bruxism but protects the dentition and reduces symptoms.
Bruxism (nocturnal); myofascial TMD pain; condylar disc displacement with and without reduction; occlusal force distribution for full-mouth reconstruction patients; pre-restorative diagnostic use (worn to verify tolerance of a new occlusal vertical dimension); post-orthodontic retention combined with TMD management.
Full acrylic coverage requires patient adjustment for a few nights. Must be equilibrated (adjusted) at delivery and follow-up appointments to ensure precise centric stops and appropriate guidance. Soft guards are NOT appropriate for TMD management (some evidence that soft guards increase clenching intensity). Fixed bruxism appliances (no evidence for superior outcomes vs. removable).
contacts, marking with articulating paper)
Must be fabricated on articulated models in centric relation (not maximum intercuspation). The posterior flat surface must be parallel to the condylar hinge axis for correct centric stops. Anterior guidance built into the acrylic anterior region. Must be finished smooth — a rough surface causes tongue irritation. CFL offers the Thermal Splint under adjacent category (OA-0321); the standard Michigan-type splint is in the bruxism/TMD product line. See also Night guard (Night guard) for related products.
anterior guidance.
posterior contacts only.
short-term use.
version.
repositioning splint.
protection without precise TMD equilibration.
Education](https://www.speareducation.com/spear-review/2015/09/muscle-deprogramming-a-source-of-confusion)
PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC8185153/)
evidence, fabrication notes.