What are “health” and “oral health”?

INTRODUCTION

Precise definitions aid understanding and communication, planning, and care. Only when health concepts are precisely defined, can attempts be made to measure them, and interventions to promote health be designed, implemented, and properly evaluated. Galileo is quoted as saying “Count what is countable, measure what is measurable, and what is not measurable, make measurable.”^[1] and much later Lord Kelvin reputedly agreed: “If it exists, measure it.”^[2] However, despite considerable research into disease, “There remains today no widespread agreement on what to measure or how to measure health in the community.”^[3] The quandary for health systems, health professionals, and researchers is that disease, while sometimes also difficult to define,^[4] is still easier to observe, describe, quantify, analyze, and interpret than health and well-being. Clinicians and researchers have, therefore, naturally gravitated toward describing health in negative terms – the presence and severity of disease and disability, and their impacts on individuals – inevitably leading to self-reinforcing sequelae.

In the absence of definitive measures, concepts of health are many and varied. These concepts and the “... physical, mental, social, spiritual, individual, environmental, functional, and other dimensions” related to them and assessed both subjectively and objectively are described more fully elsewhere.^[5] This paper considers only the definitions of general and oral health derived from these concepts. It describes the significant changes in historical definitions of general and oral health over time, the reasons for and implications of these changes, and a possible future direction for definitions of oral health. Definitions of general health have been split into two sections, before and after the landmark 1946 World Health Organization (WHO) definition. Definitions of oral health are listed together. All definitions within each group are listed chronologically in the Appendix.

HISTORICAL DEFINITIONS OF HEALTH

As with other social science constructs such as class, culture, intelligence, and happiness, concepts of health are imprecise, often used loosely, and difficult to define, although many have attempted to do so. The Greek soldier statesman Pericles defined health ~400 BCE as “… moral, mental, and physical well-being which enables a man to face any crisis in life with the utmost facility and grace.”^[6] A few centuries later, physician Olympicus defined it more simply and intuitively as “… the absence of disease.”^[7] For the ancient Greeks, physical, mental, and emotional health represented a balance of forces or humors or fluids within the body and the equilibrium between internal and external environments; disease is an imbalance of the same. Nature was the primary healer, although physicians could assist this process and even prevent illness through advice on diet, exercise, recreation, and contemplation. Health and disease could also be determined by the Gods, who may or may not respond to offerings and appeasements. The Romans adopted many of their health beliefs from the Greeks, and poet Juvenal prayed for “... mens sana in corpore sano,” a sane mind in a sound body.^[8] Indian Ayurvedic medicine is based on the balance between three primary humors, and Traditional Chinese Medicine believes that a finely tuned balance between yin and yang forces ensures health. For many Indigenous peoples around the world, illness results from social and spiritual dysfunction, and the concept of an individual’s health is inextricably linked to the health of their family, ancestors, society, lands, and spirit world.

Following Olympicus, and up to the mid-20^th century, “health” has been defined dozens of times (Appendix). With subtle differences, most definitions prioritized disease, physical fitness, function and bodily integrity, or the ability to work and achieve. Healthcare over most of human history has involved an ongoing and largely unsuccessful battle against a wide range of diseases and disabilities and premature death. Middle ages medicine relied more on religion and astrology than science,^[9] and the 18^th century French writer Voltaire cynically held that “The art of medicine is to keep the patient entertained while nature effects a cure.”^[10] Only in more recent times have social reform measures and advances in science, medical knowledge, and public health led to control or prevention or satisfactory treatment of most diseases, and people reasonably anticipating long and healthy lives with opportunities for relaxation and enjoyment.^[11] With these changes, the concept of positive health emerged, and a smaller number of definitions began to consider an extended concept of health based on enjoyment of life, and the meeting of personal and social goals.

WHO AND MODERN DEFINITIONS OF HEALTH

At the 1946 International Health Conference in New York, member states developed a constitution for the newly formed WHO. Its preamble channeled Pericles in defining health holistically and positively as “… complete physical, mental and social well-being and not merely the absence of disease or infirmity.”^[12] The definition was drafted by French doctor Raymond Gautier from the predecessor League of Nations Health Organization and derived from earlier writings by Swiss medical historian Henry Sigerist. The term “well-being” was taken from the International Labour Organization’s 1944 Declaration of Philadelphia and its “… promotion of health, education, and well-being.”^[13]

The WHO constitution was formally adopted in 1948, and the definition has remained unchanged to the present day. In the aftermath of the catastrophic World War II, the constitution was also a political statement, written by idealists who recognized the social determinants of health and disease and the importance of individual well-being. They urged government social and health reform measures to promote international peace and security and “… make mankind’s life more livable.”^[14] The emphasis by the WHO on healthy societies, not just healthy individuals, contributed to the development of generous public health systems in the UK, Canada, and other countries. Decades later, the influential Declaration of Alma-Ata^[15] and Ottawa Charter for Health Promotion^[16] added that peace, shelter, education, food, income and economic development, a stable ecosystem, sustainable resources, social justice, and equity as fundamental conditions and resources for health. Under this sweeping view, few aspects of life are not health-related.

The acceptance of a model and definition of health as being more than the absence of disease and disability involved a slow paradigm shift from a sole focus on the biomedical and pathological to a greater emphasis on the psychosocial. In one of the most highly cited of all medical papers, Engel in 1977 criticized medicine’s dogmatic adherence to the biomedical model, claiming that it “… leaves no room within its framework for the social, psychological, and behavioral dimensions of illness.”^[17]

The WHO definition of health is unapologetically aspirational and has been challenged many times as “... a pious expression of wooly idealism,”^[11] “... simply a bad one,”^[18] “... vacuous,”^[19] “... well-meaning rhetoric... totally meaningless,”^[4] “... wildly utopian” and “... more realistic for a bovine than a human state of existence,”^[20] “... famously hyperbolic,”^[21] “... an ironic icon of a bygone age,”^[22] and “Noble indeed, but too idealistic to be of much practical value.”^[23] While superficially appealing, even the WHO conceded that its definition “... does not easily lend itself to objective measurement,”^[24] and “complete” well-being may exist only if one’s expectations from life are extremely low.^[18] Under the WHO definition, a person with even the mildest disability or limitation is automatically labeled as unhealthy, even if that limitation is of little concern and has minimal impact on daily life. Others maintain that the WHO definition measures happiness, not health,^[25] and leaves little conceptual space for health-related quality of life (HRQoL),^[26] although one might equally contend that happiness, well-being, and HRQoL (and by implication oral HRQoL [OHRQoL]) are very closely related to health, even if arguably separate constructs.^[27] Even if conceptually valid, the WHO definition has little direct operational value, since it ignores the relative impacts and varying severities of different diseases and impairments, their prevalence in societies, the relative importance of physical, mental, and social health and the relationships between very different concepts, the difficulties in measuring these concepts, and that concepts of health differ within and between cultures.^[8] However, despite valid criticisms and many proposed alternatives, the WHO definition of health is still cited widely 76 years after its publication, suggesting that it has both appeal and merit.

Almost all definitions of health post-1946 that extend to the present day (Appendix) “highlight the well-being, or spiritual, and components of health”? Most have been written by non-health professionals, and in what would have been inconceivable in past eras, disease and disability are barely mentioned. These normative views accept that health and well-being are positive, not neutral states. Essential to these positive states is the striving for and attainment of a wide range of value-based goals driven by each individual’s personal and socioeconomic circumstances.

The opposite naturalist or species-typical view that health represents solely the absence of disease and disability and is value-free is still promoted in the medical literature.^[28] Callahan defined health simply as “physical well-being,” arguing that it is not the role of medicine to cure the world’s social, political, and cultural problems.^[18] Under this much narrower, and now not widely accepted view, a “health professional” might be better described as a “disease professional.”

DEFINITIONS OF ORAL HEALTH

As with general health, dozens of definitions of oral and dental health have been proposed (Appendix), with substantial development over the centuries, and greater or lesser emphases on function, disease, oral health rather than dental health, bodily health, esthetics, mental and social well-being, and the priorities and views of those providing or seeking oral care.

The current World Dental Federation (FDI) definition of oral health – “Oral health is multifaceted and includes the ability to speak, smile, smell, taste, touch, chew, swallow, and convey a range of emotions through facial expressions with confidence and without pain, discomfort, and disease of the craniofacial complex” – is now widely cited. The accompanying framework highlights physiological function and disease as core elements of oral health, but also psychosocial function and well-being, and that oral health is embedded in the larger concept of general health.

DISCUSSION

Countless definitions of health and oral health have been proposed over the centuries, the sheer number showing the value many place on precise definitions. Some have stood the test of time; others have not. Where gender is included in a definition, it is invariably male. Inevitably, new definitions will be proposed in the future and old ones refined as concepts of health become better understood through qualitative and quantitative research. The nature of health, and distinctions between health and wellness, disease, and illness is still debated at length. Complete agreement in the future is unlikely, but many criticisms of the WHO definition still favor a multidimensional model of health that includes subjective assessments and personal values and goals. Disease and disability may always be part of health and health care, but modern consensus holds that an individual’s mental and social well-being are also essential components. These are best assessed subjectively by individuals, based on their history, beliefs, priorities, expectations, and goals.

In contrast with many broad and non-biomedical definitions of general health, most definitions of oral health have focused narrowly on oral disease and function. Definitions of general health have authors from a wide range of backgrounds, but definitions of oral health are mostly written by dentists, many implying that oral health is dentist-determined. Only in recent years have some definitions recognized the mental and social well-being component of the 1946 WHO definition of general health and prioritized appearance, well-being, and the role of the oral region in speech and social interactions, despite the orofacial region having a disproportionate impact on an individual’s self-image and social confidence. Inexplicably, even multiple WHO definitions of oral health (1965, 1983, and 2003) failed to do so. Not until almost 70 years after its landmark “well-being” definition of general health did WHO include the word “well-being” in a definition of oral health.

Until very recently, few definitions of oral health considered and valued individuals’ subjective perceptions of their oral health status and well-being alongside the objective views of dental professionals. The two can differ substantially and this should not be concerning. Any disparity between objective and subjective health ratings simply presents an opportunity for further investigation, clarification, and education. Indeed, some insist that subjective ratings are preferable and most useful when they do disagree with objective measures, since in these circumstances objective measures are clearly not detecting an important factor in the subject’s environment.^[29]

Despite “health” and “oral health” being conceptually similar items, definitions of oral health have often lagged decades behind changing definitions of general health. Notably, definitions of general health underwent a slow paradigm shift around the time WHO was founded in recognizing mental and social well-being as essential components of health, and thereby valuing individuals’ subjective views regarding their own health status and expectations and desires for the future. Definitions of oral health did not undergo the same paradigm shift. Even the most recent fail to reach the inspired heights of definitions of general health. Dental authorities are unlikely to ever revert to definitions of oral health based solely on absence of oral disease and ability to chew food, but we have yet to see the oral health equivalent of general health’s “... a love of life,” “... a joyful attitude toward life” or simply “... flourishing.”

Paradoxically, one contributor to the delayed development of oral health definitions may have been a watershed in public dental health research – Locker’s conceptual model of oral health that criticized the view equating health with disease, and highlighted the importance of subjective assessments.^[30] Despite acknowledging WHO’s broad definition of health, Locker’s model and the OHRQoL tools derived from it mostly highlighted the impairments, functional limitations, discomfort, disability, and handicaps associated with oral disease, not health and well-being per se. The model’s view of oral health was, therefore, largely negative, not positive. Subsequent models of oral health have been more varied, and often less negative, but measurement tools, while all valuable, understandably still favor the easier to measure negative dimensions of oral disease over more difficult to measure positive dimensions of oral health.^[27] “And so, unfortunately, we are apt to measure what we can, and eventually come to value what is measured over what is left unmeasured.”^[31]

CONCLUSION

The future definitions of oral health may include the presence, absence or severity of oral disease, or orofacial anomaly, but they must also consider an individual’s subjective view of their own oral health status and well-being, and how these help or hinder attainment of functional, psychological, and social goals in life. Using the WHO’s and subsequent definitions of general health as a guide, as has rarely be done in the past, future definitions of oral health should extend well beyond FDI’s current “… confidence in function and expressing emotions.”

But why is this important? Prioritizing subjective well-being and quality-of-life items in definitions of oral health encourages interventions and outcomes most valued by individuals and populations, and the development of tools that evaluate such interventions and outcomes. These will include positive and aspirational outcomes, not just the negative functional, psychological, and social impacts of oral disease. Apart from the greater insight into the needs and concerns of individuals and the psychological and social impacts of disease, health services may benefit from tools that assess the subjective benefits of prevention and treatment and can therefore guide future resource allocation and improve the efficiency and effectiveness of health systems. All dimensions of “oral health” are worthy. Prevention and treatment of disease are important, but equally so are people’s beliefs, expectations and aspirations for their oral health. The success or failure of dental care and public oral health policy might therefore be best judged by the degree to which all definitional components of oral health can be assessed, measured, and achieved.