Consultant’s Corner: Nightguards vs TMJ Splints

Splints are known by a wide variety of names such as: intraoral appliance, stabilization appliance, occlusal appliance, interocclusal appliance, repositioning splint, bruxism splint, nightguard, mouth guard, and others.

Although you might have heard the terms splint and nightguard used interchangeably in the past, they do not always mean the same thing. A nightguard is a type of splint, meaning that all nightguards are splints, but not all splints are nightguards. Each type of splint is designed for a specific purpose and serves a different function as outlined below:


The types of splints noted below work in different ways to address Temporomandibular Joint Disorder (TMD). In general, splints for the temporomandibular joint (TMJ) allow your jaw muscles to relax, distribute pressure evenly across your teeth, reduce the strain on your joint, and help reposition your jaw into proper alignment.

Stabilization Splint:

Stabilization splints, also known as permissive splints, aim to eliminate harmful contact between the teeth and provide a bite surface which is harmonious with the jaw joints. This helps alleviate pain by allowing the jaw muscles to relax.

Repositioning Splint:

Repositioning splints, true to their name, aim to reposition the jaw for ideal alignment. These splints include indentations that do not allow your teeth to glide across the occlusal (bite) plane. These symptoms included disc alignment and jaw clicking.

NTI-tss (Nociceptive Trigeminal Inhibition Tension Suppression System) Device:

A NTI-tss device is worn only on the top front teeth and stops clenching and grinding. This type of NTI dental appliance for TMD is particularly helpful for reducing migraines and headaches related to facial pain.  However, because it fits on only a few teeth, it places a great deal of stress on them and that can be harmful. Also, because of its small size, if it comes off during the night, there is danger that it could be swallowed or aspirated.

Dentists usually recommend patients use TMJ splints for short-term relief only. There is concern that they can change your bite with long-term use.

Unlike nightguards, TMJ splints are often worn on both the upper and lower jaw. They are only intended to be used by people who actually have TMD.


A nightguard is designed to treat bruxism and may be recommended before a TMJ splint, as bruxism eventually may cause TMD. A nightguard is a special type of splint that helps treat bruxism by providing a barrier between the top and bottom teeth.

Nightguards are typically only worn on either the top or bottom teeth. Three of the most common types are soft nightguard, hybrid nightguard, and hard nightguard.

Soft Nightguard:

This type of nightguard helps reduce the symptoms of bruxism by putting that soft barrier between the teeth. It’s typically recommended for people with mild bruxism.

Hybrid Nightguard:

A hybrid nightguard is made of a soft rubber material inside and a hard acrylic outside. This also provides a barrier between the teeth, but it gives a more comfortable feeling inside while providing a strong barrier on the bite surface. This nightguard is typically recommended for those with moderate to heavy grinding.

Hard Nightguard:

A hard nightguard is made of hard acrylic both inside and outside. They are typically recommended for the heaviest grinders.


As a general rule of thumb, TMJ splints are not covered benefits. This is because this orthotic is usually covered under the member’s medical policy. Nightguards are a more frequently covered benefit. Actual DDKS policy is listed below.