Part 2 of Concussion Series
As we wade further into the turbulent waters of concussion injuries and custom mouthguard use, it makes sense to clearly define and understand what a concussion is. By understanding what a concussion is and how concussions arise we can start to understand how custom mouthguards may influence their occurrence and severity.
Experts at the 3rd International Conference on Concussion in Sport held in Zurich in November of 2008 agreed that a concussion is a complex pathophysiological process affecting the brain, triggered by traumatic biomechanical forces. Concussions may be caused either by a direct blow to the head, face, neck or elsewhere on the body with an “impulsive” force transmitted to the brain1. We can simplify the concept of the transmission of impulsive forces by thinking about a game of pool. The initial force/trauma that the body absorbs is like a billiard ball being struck directly by the cue. After the cue ball travels down the length of the table (the transmission), it delivers it?s energy to the “eight ball” (the brain). The eight ball rattles off into the corner pocket with a force that causes the chalk to fall off the table and a concussion ensues.
Concussions usually result in the sudden onset of short-lived neurologic functional problems that resolve spontaneously. Typically, these neurological changes are not related to a structural injury of the brain but are a temporary functional change. The resolution of the symptoms of a concussion follow a well-described course, however in a small percentage of cases, post-concussion symptoms may be prolonged.(1)
In 2005, Tomotaka Takeda, a researcher from the Department of Sports Dentistry, Tokyo Dental College, Chiba, Japan put the shock absorbing claims of EVA laminated mouthguards to the test(2). Using pendulum impact equipment and an artificial skull model connected to strain gages, Takeda and his colleagues simulated and measured, among other things, the acceleration of the head following a direct blow to the chin (transmission of the impulse force) and the distortion of the lower jaw (it?s tendency to fracture). Direct blows to the lower jaw were delivered. Takeda showed that wearing a custom EVA laminated mouthguard (like the kind manufactured by Victory Mouthguards) decreased the distortion to the lower jaw bone and the acceleration of the head significantly compared to not wearing a mouthguard. Because concussions are the result of the transmission of impulsive forces to the brain and the custom mouthguards used by Takeda and his colleagues reduced the transmission of these forces, it was concluded that mouthguards could prevent mandibular bone fractures and concussions. Experts agree however that further well-designed and exhaustive studies are vital to further substantiate these conclusions.
A Victory Mouthguard is custom made from a high energy absorbing EVA laminated material. When fitted properly and worn as directed, these custom mouth guards can greatly reduce the incidence and severity of dental trauma. Although there is some debate about whether or not a custom mouthguard can prevent concussions, there appears to be no debate that they reduce the forces translated through the jaw and to the brain. This may explain the decrease in severity of symptoms experienced by professional athletes who wear custom mouthguards and are subjected to bone crushing, jaw rattling hits when competing.(3)
- Consensus Statement on Concussion in Sport: the 3rd International Conference on Concussion in Sport held in Zurich, November 2008. P McCrory, W Meeuwisse, K Johnston, J Dvorak, M Aubry, M Molloy, R Cantu. Br J Sports Med 2009 43: i76-i84
- Can mouthguards prevent mandibular bone fractures and concussions? A laboratory study with an artificial skull model. Tomotaka Takeda, Keiichi Ishigami, Sanae Hoshina, Toru Ogawa, Jun Handa, Kazunori Nakajima, Atsushi Shimada, Tsuneya Nakajima, Connell Wayne Regner. Dental Traumatology: Volume 21, Issue 3, June 2005, pages 134-140
- Benson B, Meeuwisse W. The risk of concussion associated with mouthguard use among professional ice hockey players [abstract]. Clin J Sport Med 2005;15:395.