Athletic mouthguards serve multiple purposes in contact sports. They are known to reduce impact forces to teeth and jaws as well as reduce lacerations to soft tissues.
In fact, the concept of reduced impact forces is an important characteristic of mouthguards as there are claims that those who wear one have a reduced chance of suffering from concussions.
When designing mouthguards with respiratory ease and speech in mind, we use a 2 step process. The first step involves determining the mouthguards shape and design features, and the second step involves determining the mouthguards material texture.
Step 1: Mouthguard shape and design features
In order to increase our mouthguards performance and the energy absorption capacities of its EVA material, we incorporate small air holes throughout the guards’ outer frame strategically placed in low impact areas of the mouth.
What our studies have shown:
To understand the difference in impact absorption between mouthguard designs with and without air holes, we created two identical samples and differentiated them only by the presence of air holes in the material.
Then, from the two samples, we made 4 versions of each and impact tested them using a pendulum apparatus to generate 4.4J impacts at speeds of 3 m/s. Each test sample was impacted five times but once only at each impact site for a total of 20 calculated impacts.
Once the tests complete, the results were quite conclusive. The transmitted force in the EVA material with air holes was 10% lower than the EVA material without air holes. In fact, the sample with air holes measured a transmitted force of 3.88kN while the sample without measured a transmitted force of 4.04kN.
The figure below shows the difference in transmitted forces between both test samples.
The blue line represents the transmitted force in material without air holes. The red line represents the transmitted forces in the material with air holes.
By visualizing the graph, it is easy to conclude that the best energy absorption and least transmitted force occurred in the air holed material. In addition to reducing the transmitted forces, adding our holes also make our mouthguards more lightweight, durable and comfortable in the wearers’ mouth.
Most important, the reduced material helps increase athletic performance by allowing easier air intake and more impact protection.
Step 2: Mouthguard material texture
The next step in our mouth guard design process is determining the appropriate material texture, also known as material hardness.
By gathering our pendulum impact results and compiling them with material hardness tests from Rudolf Gunz and Co, we are able to further enhance the protective capabilities of our EVA polymer material.
When analyzing transmitted forces through materials, another important characteristic to consider is material hardness (Shore A Hardness Scale). Because harder materials structurally allow less elasticity, they tend to transmit more force when impacted which is why their understanding is crucial when discussing mouth guard engineering. By combining the right material hardness with strategically placed air holes, it is possibly to maximize impact absorption while keeping the mouth guard extremely comfortable and lightweight in the mouth.
At Nxtrnd, we've determined that the perfect material hardness should feature a Shore A hardness of 83. Our research has shown that under the same conditions (magnitude of impact force, thickness of test samples and similar air conditions) mouthguards of Shore A hardness 83 with air holes in the frame transmit 32% less forces compared to the standard EVA polymer without holes.
To find a mouthguard designed for your sport and position, please click here.