Here's what Dr. John Stenger's report had to say about Mouthguards and CERVICAL INJURIES: Dr. John Stenger's classic 5-year clinical study on Notre Dame football players began in 1958 and was published in 1964. Dr. Stenger, the initiator of the concept of physiologic dentistry, based much of his work on that of James B. Costen, MD, a Washington University otolaryngologist. By means of before and after cephalometric radiographic tracings. Stenger demonstrated differences in the position of the mandibular condyle, the hyoid bone, and the cervical vertebrae (C2-C4) when the teeth were in centric occlusion versus when the bite was opened by a custom-made mouthguard to the vertical dimension of the freeway space (approximately 2-4 mm). In the spring of 1963, with the encouragement of then trainer Gene Paszkiet, a decision was made to equip the entire Notre Dame football team with a new model ethylene vinyl acetate (EVA) mouthguard. As expected, the number of injuries to the teeth and jaws declined. There was also an impressive reduction in cerebral concussions. A serendipitous correlation between wearing the mouthguards and a decrease in neck injuries was an important finding. A reduction in the number of neck injuries was an unexpected result of wearing the mouthguards. Neck injuries had increased since the use of the face bar had become mandatory. So play it safe out there.