There are many different philosophies when it comes to constructing a nightguard. In its simplest form, the primary function of a nightguard is to protect the teeth from the destructive actions of clenching and grinding during sleep. Upper nightguards with a flat surface are a popular and simple solution to to this problem. However, after more than 30 years of studying and treating bites, joints, and airway issues, I have found that while many upper nightguards may protect the teeth from tooth-on-tooth damage, they often disregard important elements of a balanced bite and an open airway.
Traditional upper nightguards are generally made by taking a single impression of the top teeth and palate, and then sending that single impression to a laboratory to have a simple nightguard made. Little attention is given to the physiology of the joints and muscles, resulting in many upper nightguards that actually shove the lower jaw backwards, causing pain and compression in the joint space. Many of these nightguards are also constructed with a flat biting surface for the bottom teeth to slide against. The idea is that the teeth are grinding around anyway, so why not give them full freedom to do so?
The problem with that concept is based on a fundamental misunderstanding of why people clench and grind in the first place. Stress can certainly play a role, but nighttime clenching and grinding can also be a physiological effort to open the airway or to find a more comfortable resting place for the teeth that better supports the joints and muscles. A flat plane that the teeth literally skate around on can actually causing grinding to increase as the muscles and joints struggle to find any resting place at all.
Upper nightguards can also exacerbate breathing problems, especially for those people who already snore, suffer from allergies, or have any form of sleep apnea. Most upper nightguards are fairly thick across the palate. This construction crowds the tongue further back into the throat, constricting the airway. When this happens, patients will often stop wearing the nightguard even if they don’t know why because it feels claustrophobic or simply “too big”.
In my practice, I always recommend and construct lower nightguards for my patients. Even if a patient has no known joint or breathing issues, my goal as a neuromuscular dentist is to always protect the balance that already exists. A lower nightguard allows more room for the tongue and, when constructed properly, holds the lower jaw in a neutral, relaxed position to support the joints and muscles.
When we make a lower nightguard, impressions of both the upper and lower jaw are taken, and a bite registration is used to determine the ideal relationship between the upper and lower teeth when the joints and muscles are at rest. A bite, or resting place, is carefully constructed into the surface of the nightguard. This bite is not a locked position, but rather a subtle suggestion to the teeth to settle into a more relaxed position when not engaged in a grinding activity. Full freedom of movement is still possible and careful attention is paid to potential interferences when the jaw moves forward and side-to-side during the final fittings.
A nightguard is a simple device in theory, but like any other treatment or device that introduces a change in the body, great care must always be taken to reduce or eliminate any unnecessary and unwanted changes to other systems. If you are considering a nightguard, or you have questions about the construction and efficacy of your current nightguard, I encourage you to seek out an opinion from a neuromuscular dentist. Current patients or individuals who would like to become patients within my practice are always encouraged to call or schedule and appointment to further discuss my approach to nightguard construction and to determine if a nightguard is the correct appliance to address all your functional needs.