Dr. Tim Walilko – Lead author

In 2010 there were an estimated 1.7 million traumatic brain injuries (TBI) up from 1.4 million in 2004.[1] Despite the increasing number of TBIs sustained every year, there is little information regarding the impact threshold at which they occur or how to prevent them. Five experts in diverse disciplines presented at the May 2011 Oklahoma State Athletic Trainers Associations Conference on potential mechanisms and solutions to jaw joint related concussions. This is a summary of their presentations.

Practical Experience and Observations

Cory Schafer, president of the International Sport Karate Association, with 30 years of experience regulating martial arts and combat sports presented a commonly regarded premise. "If you want to knock someone out, you hit them on the chin". The jaw is the "sweet-spot" for scoring knock outs. Further evidence is demonstrated by terms such as "glass jaw" and "weak chin" which are used to refer to someone who is easy to knock out…." Mr. Schafer also observed that when dual arch jaw joint protection technology is used, the same strike to the chin often does not have the same devastating effect. Based on experience with dual arch mouth guards the International Sports Karate Association is moving towards a mandate for the use of dual arch for all sanctioned events. He posed the question "What exactly is the science behind the dual arch technology that makes it so effective in combat sports, and can it be integrated into helmet sports to better protect our young athletes?"

The Anatomy of a Concussive Blow to the Chin

When a combatant’s punch is directed at the chin of his opponent, a large portion of the applied punch force can be transferred through the mandibular into the structures at the base of the skull. The forces generated by a straight punch to the chin can range from 1,990 to 4,741 Newtons.[1]  Forces of the same magnitude can be generated by the chin cup of a helmet after a blow delivered to the facemask. Dr. Ken Moser explained how in both instances the transmitted force travels through the temporomandibular joint (TMJ) into the glenoid fossa and ultimately deforming the structures at the base of the skull. The fossa is so thin that light can pass through this region in a dry skull. Deformation of these thin bones comprising the skull base could affect the intracranial structures within this region. Symptoms include: sensitivity to light; "Migraine" headaches; and radiating headache pain from forehead to eyebrow area. In separate discussions, Dr. Kem Moser and Dr. Robert Mongrain discussed how dual arch oral appliances and the use of energy absorbing materials in their construction could potentially reduce the force of the blow that deforms the structures at the base of the skull.

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