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” [32], 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.

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.

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 [16]. Bicycle helmet use corresponded with a greater level of caution in one study [33]. In another, helmeted bicyclists exhibited a much smaller risk of major trauma than non-helmeted bicyclists [34]. 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 [35]. 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 [36]. 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 [37]. 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 [38]. 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 [39].

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 [40]. 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 [41] 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.

2.7 Conclusion

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.