NCAA ISS form
The longevity of the NCAA ISS and its consistency in definition, denominator, and methods of data collection is unique in sports medicine literature as a source of information on the epidemiology of sports injuries in intercollegiate athletics. The High School RIO is patterned after the NCAA ISS and offers similar consistency in definition, denominator, and methods of data collection for high school athletics . However, because athletic trainers rather than dentists gather the information in a setting without optimal diagnostic tools such as intraoral radiology, data from NCAA ISS and High School RIO lacks optimal validity and reliability.
Studies using NCAA ISS and High School RIO provide information on incidence of traumatic dental injuries, injury rates, and comparison of traumatic dental injuries to other types of injuries sustained by college and high school athletes and can identify trends in sports-related traumatic injuries because of consistent methods employed over time. This consistency is invaluable for those who want to use the data to support decisions to institute practices to prevent sports-related traumatic injuries.
Data from High School RIO has been used to describe the epidemiology of rare injuries sustained by high school athletes. A 2-year prospective study  identified five injuries or conditions considered to be rare or unusual but which can result in high morbidity and a heavy burden on health care. More common injuries, like sprains, strains, and fractures, have a much higher statistical profile, and therefore the identification of risk factors and efforts at prevention has been focused there. In this study rare injuries and conditions included dental, eye, and neck and cervical spine injuries and heat and dehydration illnesses. Although these injuries were rare when all sports-related injuries were pooled, they actually made up a high proportion of reported injuries in some sports. Rare injuries and conditions accounted for 321 injuries, approximately 3.5% of all athletic injuries. A total of 23 dental injuries occurred in this population during the 2-year study, translating to an injury rate (IR) of 0.65 per 100,000 athletic exposures (AEs), with baseball (IR of 3.22 per 100,000 AEs) and girls’ basketball (IR of 1.12 per 100,000 AEs) having the highest rate of dental injuries. In this study only injuries to the teeth were counted as dental injuries. Other studies include soft tissue injuries to the lips and oral cavity as traumatic dental injuries, which render pooling of data or comparison of studies problematic.
High School RIO provided the data for another study, which looked only at dental injuries . This study documented the rate of dental injuries, as injuries per athletic exposure, in various sports and under various conditions, the immediate cause of the injuries, and whether a protective mouthguard was worn at the time of injury. There were 222 dental injuries during 24,787,258 AEs, accounting for 0.5% of all sports-related injuries. The overall injury rate was 0.90 per 100,000 athletic exposures. Girls’ field hockey had the highest rate of dental injuries (3.9 per 100,000 AEs) followed by boys’ basketball (2.6), boys’ baseball (1.5), and boys’ wrestling (1.4). All dental injuries were recorded regardless of whether they resulted in restriction of participation. In this surveillance study, lip lacerations were the single most common dental injury, comprising 36.5% of all such events. Note that this was in contrast to the study reported above in which only injuries to the teeth were counted, not injuries to the soft tissue.
Data from the National Collegiate Athletic Association Injury Surveillance System (NCAA ISS) was used to report changes in incidence rate of traumatic dental injuries over a 10-year period at a single NCAA institution . Incidence rates (IR) were calculated for 19 separate teams, involving 15 different sports, and were highest for men’s and women’s basketball. Of particular interest in this study was the fact that the women’s basketball team instituted a mandatory mouthguard policy 4 years into the study. The IR before the policy was instituted was 8.3 injuries per 100 athlete-seasons. After all players were required to wear mouthguards, the IR dropped to 2.8. Due to the small sample size and relative infrequency of injuries, this difference was not statistically significant.
These examples of NEISS , NCAA ISS, and High School RIO in action point out that even when using a well-designed instrument on a representative population, variations can still occur in the design of studies and details of how the instruments are used. These variations rob the studies of universal applicability and make study-to-study comparison problematic. As a result, even studies that employ these ideal instruments often fall short of generating data reliable enough to drive policy.
2.6 Injury Prevention and Risk Compensation
The principle of Occam’s razor suggests that the simplest solution to complex problems is the best and that if a cause is both true and sufficient to explain a phenomenon, there is no need to look further than addressing that single cause. In the case of traumatic dental injuries, this “true and sufficient cause” is the transfer of mechanical energy to the teeth and mouth. In the case of sports-related traumatic injuries, the mechanical energy is transferred from the ground or other immovable object, a projectile, or a device used to propel the projectile. Following the logic of Occam’s razor, efforts to curtail or prevent athletic dental injuries should be focused simply on interrupting the transfer of energy rather than addressing the infinitely complex web of intrinsic and extrinsic factors associated with traumatic dental injuries.
Given that traumatic dental injuries, like injuries in general, are “the unintended consequences of individual actions in a risky environment” , there are three recognized strategies for injur prevention: persuade those at risk to change their behavior, require behavior change by law or rule, or provide automatic prevention through product and environmental design.
Strategies for Injury Prevention
Persuasion to promote behavior change
Require behavior change through enforced laws or rules
Provide automatic prevention through product and environmental design
In general, rules work better than persuasion, and automatic protection works better than rules. Applying this model to the epidemiology of sports-related traumatic dental injuries and adhering to the principles of Occam’s Razor, it is easy to conclude that since the automatic protection of the teeth and mouth provided by mouthguards and face masks is proven effective in the most high-risk sports, some variation of one or both should be written into the rulebooks of other less-risky activities. However, there is an intrinsic factor of human behavior that brings such a policy into question: risk compensation.
2.6.1 Risk Compensation
Risk compensation theory is based on the idea that people change their behavior in response to a real or perceived risk.
Theory that people change behavior in response to real or perceived risk
Increased perceived risk, more cautious
Decreased perceived risk, less cautious
If risk increases, people become more cautious, as when drivers slow down when roads are icy to mitigate that risk. If risk decreases, however, do people consciously or subconsciously increase risky behavior? If so, does protecting one part of the body during sports participation lead to behavior that places other parts of the body at greater risk for injury? In the case of facemasks and mouthguards, does wearing them to eliminate the risk of injury to the face, eyes, and teeth increase the risk of other injuries due to carelessness or more aggressive play? The theory of risk compensation suggests that it does. Of particular interest in the field of sports medicine is the incidence of concussion and spinal cord injury.
The epidemiology of risk compensation and other behavioral factors in sports-related traumatic injuries is not conclusive. There are few studies of individual risk-taking behaviors before and after adoption of safety measures, so it is impossible to determine whether risk-taking behavior increases, decreases, or remains the same. The literature on this topic is characterized by conflicting results from a number of sources . Bicycle helmet use corresponded with a greater level of caution in one study . In another, helmeted bicyclists exhibited a much smaller risk of major trauma than non-helmeted bicyclists . The findings of both of these studies are the opposite of what would be predicted by risk compensation theory. However, it was shown that when hard shell helmets and face protection were introduced into football, tackling fatalities increased dramatically, leading to the hypothesis that players felt so well-protected that they could use their head and face for tackling . Rule changes making it illegal to “spear,” or lead with the head while tackling, along with improvements in helmet construction resulted in a decrease in such fatalities. This suggests that risk behavior can be mitigated by rule changes and better safety equipment. In the sport of ice hockey, one study suggested that players with the greatest amount of protection, a helmet with full face shield, were less likely to suffer severe injuries or engage in illegal aggressive play than those wearing half-shields, a finding that is inconsistent with risk compensation theory . On the other hand, a survey of 140 adolescent rugby players found that 2/3 of the respondents felt increased confidence in playing harder while wearing protective head gear . A survey of a convenience sample of 190 recreational league hockey players with a mean age of 34 found that 70% of the players felt they played more aggressively when wearing full face protection and reported a higher incidence of injuries over time . A study of the injury profile in ice hockey from 1976 to 1979, the 1988–1989 season, and the 1992–1993 seasons in Finland found that the incidence of severe injuries increased over time, though not to protected body parts like the face and head. The authors concluded that more aggressive and reckless play contributed to these findings .
While risk compensation theory suggests that greater protection from injury of one type increases the risk of injury of another due to increased risk taking, some argue that extrinsic factors, including better equipment and playing fields, new techniques, rule changes, and greater dedication to the intrinsic factors of physical fitness and strength training have, in the process of making modern games faster and more exciting for the players and spectators, made them more dangerous. In this model the proposal to introduce enhanced personal protective equipment is the result of an increased risk of injuries due to intrinsic and extrinsic factors. A descriptive epidemiological study to determine the incidence of head, face, and eye injuries in the sport of Women’s Field Hockey in its modern form, with increased intrinsic and extrinsic risk factors as noted above, was conducted using NCAA ISS data from the 2004–2005 to 2008–2009 seasons . Concussions were the most commonly reported injury, most of which resulted from direct contact with another player or contact with a stick. This is somewhat surprising because women’s field hockey is a non-contact sport in which elevation of the stick to the level of the head is illegal. The author concluded that stricter enforcement of the rules to control overly aggressive play may be the best solution rather than introducing better protective equipment, which could result in more aggressive play. At this time the governing body of the sport in the United States is arguing against enhanced head protection for fear that it may lead to more reckless and aggressive play due to the false sense of security such equipment may impart.
These studies fall well short of offering enough information to guide policy. They are examples of how risk compensation may manifest in the area of sports-related traumatic injuries, however, and suggest that studies of the effectiveness of protective equipment and rules designed to protect players from specific injuries should take a broad enough view to consider whether negative side effects might accrue and increase the risk of other, more serious injuries.
A view of sport injury mitigation that considers all injuries and factors contributing to them holds more promise for making sports safer for participants than focusing on a series of isolated injuries. McIntosh  advocates taking a biopsychosocial approach to sport injury and considering the potential of extrinsic and intrinsic risk factors either increase or decrease the overall injury risk. This biopsychosocial model recognizes the primary contributors to disease—in the case of sports-related traumatic dental injuries, the mechanical forces transferred to the teeth and surrounding structures—but also acknowledges that environmental, social, and behavioral factors must be considered to devise effective methods for the prevention of sports-related traumatic injuries, including dental injuries.
This classic “chicken or the egg” dilemma—does enhanced protection lead to more aggressive play or does more aggressive play demand enhanced protection—is yet to be resolved. In the meantime, injury surveillance data from well-designed and executed studies offers the best hope to illuminate the issue of sports-related traumatic dental injuries and offer solutions that are consistent with the culture of the individual sports and which do not increase the risk of other sports-related traumatic injuries.
Epidemiology is the formal, systematic study of the distribution and determinants of health-related states or events and the application of this study to their prevention and control. In the context of this book, “health-related states or events” are sports-related traumatic dental injuries. Central to the study of the determinants of this condition is the presumption that traumatic dental injuries do not occur randomly but as a result of exposure of the individual to risk factors associated with such injuries. Analytical injury surveillance studies are employed to identify the factors that contribute to traumatic dental injuries, with the ultimate goal of instituting policies and protocols to mitigate risk. Injury surveillance studies are observational rather than experimental, so many studies of similar design and execution need to be combined and data from them pooled to draw an accurate picture of the issues. Since the etiology and immediate cause of sports-related traumatic dental injuries are well-established—the transfer of mechanical energy to the teeth and mouth due to contact with the ground or some other fixed structure, contact or collisions with another participant, or being struck by an object, either a projectile such as a ball or puck or the device used to launch the projectile, like a stick or racket—attention in analytical observational studies focuses on intrinsic and extrinsic risk factors for traumatic dental injuries. Intrinsic risk factors include the physical characteristics and psychological profile of individual athletes, including risk behavior and risk compensation. Extrinsic risk factors include type of sport, position played, exposure time, level of competition, coaching, referees, and protective equipment. The list of factors contributing to the risk of traumatic dental injuries in sports underlines the complexity of the issue of risk mitigation. Because each athlete has a unique set of intrinsic variables that may confer greater or lesser risk for injury, the interplay among and between intrinsic and extrinsic factors present an infinite range of risk for participants in athletic events. The simplest solution for mitigating sports-related traumatic dental injuries, protecting the mouth through the use of a mouthguard or facemask, is also the most effective irrespective of other factors. However, risk compensation theory suggests that face and mouth protection may increase risk for more serious injuries. The nature of sports makes it impossible to eliminate all risk of injury. Injury surveillance data from well-designed and executed studies that take a broad view of sports-related injuries and factors affecting them offers the best hope to illuminate the causes of sports-related traumatic dental injuries and offer solutions for their mitigation that are consistent with the culture of the individual sports and that do not increase the risk of other injuries.