Performance-enhancing mouth wear and craniofacial neurometabolic physiology.

The use of some type of oral appliance to enhance human performance, decrease stress or improve strength, has occurred throughout human history, from ancient soldiers to modern athletes. To date, the science describing this phenomenon has been poorly understood, and the research has been limited. The goal of this paper is to review the efforts to improve human performance with oral appliances, and the research exploring the science behind these efforts. For the past 40 years, it has been suggested that mandibular position could affect upper body strength and, hence, athletic performance. In the 1980s, this concept seemed to have little scientific support and was highly criticized.1,2 More recently, research suggests mandibular position and oral appliances positively affect not only upper body strength, but also endurance, recovery after athletic competition, concentration, and stress response.3 This information could revolutionize the practice of dentistry. This paper reviews the literature and details the early research regarding mandibular position, clenching, and oral appliances and their effects on physiology and human performance. THE QUEST TO IMPROVE HUMAN PERFORMANCE Legend and history provide a glimpse of the beginnings of performance enhancement and oral appliances. Roman soldiers were said to use leather straps between their teeth to improve their prowess in battle. Native American women would bite on sticks during childbirth to ease delivery. Perhaps the most dramatic example of this phenomenon is from the US Civil War. Surgical options for devastating wounds from heavy lead bullets were limited. As a result, the treatment of choice for many of these wounds in the extremities was amputation. At that time, general anesthesia was in its infancy (in 1844, Horace Wells, a dentist, was the first to use nitrous oxide to induce the loss of consciousness for surgery). Therefore, soldiers were given bullets to bite on during these procedures to help them endure the agony, and the phrase “bite the bullet” was born. What was it about the action of biting a bullet that could help these soldiers deal with the incredible stress created by these crude operations? Although there were early forays into these concepts of occlusion, oral appliances, and human performance, the quest for optimal jaw position and its relationship to performance began in earnest in 1958 under Stenger et al at the University of Notre Dame.4 A starter on the football team, Jim Schaaf, suffered a concussion and subsequently Ménière’s disease, a recurrent prostrating vertigo associated with generalized dilation of the membranous labyrinth of the inner ear, was diagnosed. The serious nature of the disease prevented Schaaf from competing. The researchers believed he had a temporomandibular joint (TMJ) problem, contributing to his equilibrium issues, and received permission from the coaches to examine him. The researchers placed cotton rolls over the player’s back teeth and instructed him to swallow; the patient stated that his ears had cleared for the first time in weeks. It was determined that a splint and special mouthguard would be made: the patient wore the splint continuously and used the mouthguard during practice. In 2 weeks, the patient’s equilibrium returned to normal and he resumed his starting role 4 Compendium—Volume 30 (Special Issue 2) *Executive Director, Bite Tech Research Institute; Clinical Assistant Professor, Department of Primary Care Dentistry, University of Minnesota School of Dentistry, Minneapolis, Minnesota; Private Practice, Lake Elmo, Minnesota Performance Enhancement and Oral Appliances Mark Roettger, DDS* LITERATURE REVIEW