The Complete Guide to Occlusal Splints: Michigan, Tanner, Soft, Hard & Dual-Laminate

“Occlusal splint,” “nightguard,” “bite guard,” “occlusal guard” and “deprogrammer” are often used as if they mean the same thing. They don’t. They describe genuinely different appliances — different designs, different materials, and different clinical jobs. Prescribing the right one comes down to what you are actually treating: protecting teeth from bruxism, calming muscular pain, or managing the temporomandibular joint (TMJ).

This guide covers every main type of occlusal splint, what each is for, and which appliance in our range matches it — so you can prescribe with confidence and send us exactly what we need to make it.

What an occlusal splint actually does

An occlusal splint is a removable appliance — almost always acrylic — worn over the biting surfaces of one arch. Depending on how it is designed, it will do one or more of the following:

• Protect the teeth from the wear, fracture and abfraction caused by grinding and clenching
• Distribute occlusal load evenly across the arch instead of concentrating it on a few teeth or restorations
• Relax the elevator muscles (masseter and temporalis) that drive parafunction
• Stabilise the temporomandibular joint by providing a repeatable, comfortable jaw position
• Deprogramme the muscles, in the case of an anterior deprogrammer

Most splints are worn at night, because grinding and clenching are frequently nocturnal, but some anterior deprogrammers are worn on a diagnostic or therapeutic basis during the day.

The two families: full-coverage and partial-coverage

Almost every named splint falls into one of two groups, and knowing which is which is the key to prescribing safely:

• Full-coverage (stabilisation) splints cover all the teeth in the arch. Because every tooth is held, they can be worn long-term with a low risk of unwanted tooth movement. The Michigan and Tanner appliances, and the soft, hard and dual-laminate nightguards, are all full-coverage.
• Partial-coverage (anterior) splints deliberately contact only a few front teeth and hold the posteriors apart. They are powerful muscle relaxers but, because the back teeth are free to move, they are generally used short-term and supervised to avoid over-eruption or occlusal change.

Soft splints (soft nightguards)

Made from flexible EVA, soft guards are comfortable and quick to adapt to, which makes them a sensible first appliance for mild bruxism or for a nervous patient. The trade-off is durability — heavy grinders can wear through a soft guard, and a minority of patients actually clench harder against a soft surface. Best treated as an entry-level or short-term option.

→ In our range: the soft nightguard, in 1–5 mm medical-grade EVA.

Dual-laminate (soft/hard) splints

A dual-laminate splint gives you the best of both worlds: a soft inner surface against the teeth for comfort, bonded to a hard outer shell that resists wear and holds its shape. This combination usually delivers the best compliance for moderate to severe bruxism, because the patient gets the comfort of a soft guard with the protection of a hard one.

→ In our range: the standard soft/hard nightguard (2 mm soft inner + 1 mm hard outer) and the extra-thickness soft/hard (1 mm soft + 2 mm hard) for heavy grinders who wear through a standard guard.

Hard acrylic splints

A rigid acrylic splint is the most durable option and the workhorse for moderate to heavy bruxism. It protects the teeth, holds its shape night after night, and — importantly — can be adjusted to give a precise occlusal scheme, which is what makes the named designs below possible. The trade-off is a slightly longer adaptation period than a soft guard.

→ In our range: the hard nightguard in solid hard acrylic. As an alternative, a Zendura A retainer doubles as a thin hard bruxism appliance for lighter cases.

The Michigan splint

The best-known full-coverage hard splint. A Michigan splint is a maxillary (upper-arch) stabilisation splint adjusted to centric relation, with a flat occlusal plane, even bilateral posterior contacts, and canine guidance — so that on lateral and protrusive excursions the back teeth disclude and the guidance is taken by the canines. Developed at the University of Michigan by Ramfjord and Ash, it remains the reference stabilisation-splint design — and a small freedom in centric (a flat contact zone of roughly 0.5–1 mm) lets the jaw settle rather than locking it to a single point.

The purpose is to give the whole arch even, simultaneous contact in a stable joint position: this relaxes the muscles, protects the teeth, and provides the repeatable position that makes it the standard choice for combined bruxism and TMD, jaw pain and headaches. (You will also see it called the centric relation splint, stabilisation appliance or superior repositioning appliance.)

→ In our range: we make Michigan splints as a full-coverage hard nightguard. Send both arches and a centric bite so we can build and balance it correctly.

The Tanner appliance

The Tanner appliance is the mandibular (lower-arch) counterpart to the Michigan. It uses exactly the same stabilisation principle — even contacts, a flat plane and canine-guided excursions in centric relation — but is constructed on the lower arch. You would choose a Tanner over a Michigan when a lower appliance suits the patient better, for example for speech, aesthetics, or to work around existing upper restorations. We make these to the same specification as our hard Michigan-type splint.

Anterior deprogrammers (AMPS / NTI-type)

A different tool for a different job. An anterior midpoint contact splint (AMPS) — also called an anterior deprogrammer or permissive bite plane, and including designs such as the Lucia jig, the SVED, the Hawley bite plane and the small NTI appliance — provides a single point of contact at the front so that only the lower incisors meet it and every posterior tooth is held apart (by around 2–3 mm).

By removing the back-tooth contacts, it interrupts the habitual clenching pattern and lets the elevator muscles release. This makes it a potent muscle relaxer: surface-EMG studies have shown that anterior-contact splints reduce clenching force to roughly 20–30% of a patient’s maximum, calming temporalis, masseter and lateral pterygoid activity. It is used for muscular TMD, clenching and tension-type headaches, and as a diagnostic deprogrammer before restorative or occlusal work.

Because the posteriors are free, it is a short-term, supervised appliance rather than a long-term nightguard.

→ In our range: the B-Splint and the DAR-AL — both anterior midpoint contact splints in a 1 mm soft + 1 mm hard dual laminate. Send both arches and a centric bite.

Occlusal splints at a glance

How to choose

A rough decision guide by presentation:

• Mild grinding, or a first appliance → a soft nightguard
• Moderate to severe bruxism, comfort matters → a dual-laminate soft/hard
• Heavy grinder, durability is the priority → a hard acrylic guard (or extra-thickness soft/hard)
• Bruxism and TMD, jaw pain or headaches → a Michigan or Tanner
• Muscular clenching, tension headaches, or deprogramming before restorative work → an anterior deprogrammer (B-Splint or DAR-AL)

Two things worth remembering. First, grinding and clenching are not the same — a grinder wears the appliance surface (favouring hard or dual-laminate durability), while a clencher loads the muscles (where an anterior deprogrammer can help). Second, the best splint is the one the patient actually wears, so comfort and compliance matter as much as the theory.

Not sure which to prescribe? Our bruxism appliance picker walks through a few questions and suggests an option to discuss — a guide for professionals, not a prescription. And for the soft-vs-hard question specifically, see our guide to hard and soft nightguards.

What we need to make one

• Single-arch soft, hard or dual-laminate guard — one upper or lower scan or impression, with the arch and thickness specified.
• Michigan or Tanner splint — both arches (upper and lower) plus a centric bite registration.
• Anterior deprogrammer (B-Splint or DAR-AL) — both arches plus a centric bite registration.

Send cases digitally through our scan workflow — from any major intraoral scanner, with free 3D-printed models included — or post an impression using our postal options. If you are unsure what to send, our scan and impression requirements spell it out.

How we make them

Every splint is made to your prescription and finished by hand in our Christchurch lab by GDC-registered technicians, in a DAMAS-accredited laboratory that has been making dental appliances since 1978. Hard nightguards carry a 6-month warranty and soft guards 3 months (see our warranty terms), and every appliance has a clear standard turnaround with Gold and Silver express options when a patient is booked in.

Browse the full bruxism appliance range, or send us a case and we will take it from there.