Samuel F. Dworkin
There is abundant evidence from epidemiologic and clinical research, and more recently from behavioral neuroscience (supported by brain imaging studies), that the psychosocial environment contains potent risk factors for pain, especially chronic pain.1,2 The term psychosocial encompasses both factors within the individual (eg, anxiety, depression) and factors in the environment that influence how patients might express pain and/or seek treatment. These factors may be as diverse as the availability of dental treatment and pain medications or the way in which prior experience (learning and memory), culture, and society shape how people reveal their pain experience. Most importantly, an understanding of the psychosocial aspects of the pain experience expands possibilities for pain management by creating opportunities for biobehaviorally based treatments that can modify the emotional, cognitive (thinking), and behavioral status of a patient to achieve the following objectives:
1. Produce a more compliant and better informed patient
2. Eliminate or minimize negative physiologic and emotional states—especially depression, anxiety, fear, and the anticipation of pain
3. Potentiate the action of sedative, analgesic, and anesthetic pharmacologic agents used to control pain and anxiety
4. Introduce cognitive-behavioral methods to assist the patient in self-management and enhanced self-control for both acute and chronic pain, with and without analgesic or sedative medications
This chapter addresses the perceptions, appraisals, and behaviors shown by people reporting dental and orofacial pain. Some biobehaviorally based approaches to the management of acute pain are discussed in chapter 11, while those applicable to persistent or chronic pain are interwoven throughout the chapters in section IV, Management of Orofacial Pain: Principles and Practices. It is important to remember that the stomatognathic system is responsible for several life-sustaining physiologic processes, including eating, breathing, swallowing, and verbal as well as nonverbal communication. Psychologic factors play an important—some would say a central—role in the perceptions, appraisals, and behaviors of people when pain arises in such a biologically and personally important part of the body as the face and mouth.3,4
Types of Pain
Patients seek out dentists for relief of pain arising from toothache or periapical inflammation that can reach excruciating levels, and many are driven to dentists for relief of diffuse longer-lasting orofacial pain caused by neurologic or musculoskeletal factors.
The expectation that the dentist can relieve pain has been strongly positive for dentistry, and dentistry has in fact learned a great deal about pain and pain control, especially when the pain is acute. Alleviation of the pain of dental procedures has been developed to a high degree, and for most people requiring routine dental care, pain associated with treatment is largely preventable. Each clinician must learn how best to respond to the anxiety or other emotions that accompany a patient’s experience; evidence shows that these psychologic processes have a direct influence on acute pain threshold and tolerance levels. This is true whether the pain is associated with treatments or is postoperative, and whether it accompanies dental, medical, surgical, or invasive diagnostic procedures.4
Chronic neuropathic and musculoskeletal pains are not only perceived by patients as more diffuse and more persistent types of pain than more common acute dental pain but, as the name implies, remain more resistant to quick or simple resolution (see subsequent chapters on pain management). The amount and even the location of chronic pain, as well as the behaviors of the patient, are only poorly predicted by physical events. Atypical odontalgia, for example, is usually associated with poorly defined pathologic markers inconsistent with expressed pain perception and behavior. Similarly, myalgia can be a source of minor inconvenience to some patients; for others, it can become a major decades-long disorganizing force associated with significant depression and disruption of everyday activities—yet, there may be no detectable physical change to distinguish the two conditions. So, the impact of persistent pain often cannot be understood in terms of pathology. It is the deleterious and life-changing quality of chronic orofacial pain that makes it such an important area for study and action by researchers and clinicians alike.
Biomedical Models of Pain
The subjectivity of pain means that many biomedically oriented health care providers do not believe that it is critical to attend to patients’ descriptions of how pain affects their daily lives, since such descriptions are not biologically based. Often, interest in psychosocial factors is equated with the assumption that the pain experience is imaginary/not real or is being made up by the patient, especially when the clinician cannot find a biologically plausible explanation for the pain.
Thus, mechanistic and strictly biomedical views of pain, while appealing because of their deceptive simplicity, are scientifically unwarranted. For example, it is not considered likely that a single “pain gene” will be discovered which, in isolation, determines the varied ways in which people around the world express complex conditions such as chronic pain (see chapter 9).5,6 The biomedical model has been succeeded by a biopsychosocial model (more thorough discussion follows) that clarifies how physical events in the body can give rise to pain and pain relief–seeking behaviors that are influenced by the patients’ pain history, gender, and ethnicity as well as to factors in the environment (eg, having to go to the dentist) that are equated with pain or the potential for pain.
The Neurologic and Psychosocial Interface
Current neurophysiology and cognitive neuroscience provide a biologic basis for understanding how emotional, cognitive, and behavioral processes can become linked and stored, preserving memories and belief systems that influence the pain experience and guide actions we take to cope with pain. There is increased acceptance among patients and clinicians alike that the complex, hard-to-understand pain-related behaviors are real bodily processes that result from complex central processing of pain information. It is important to understand that pain, while it is in the brain, is not “all in the head” given the pejorative and highly judgmental sense the latter phrase unfortunately conveys.
Biopsychosocial Model of Pain
Figure 12-1 presents a schematic for integration of physiologic or pathophysiologic activity with associated psychologic states and socially and culturally determined behavior. The model, known as the biopsychosocial model, is currently accepted as the basis for understanding complex physiologic and psychosocial interactions evident in all disease and illness. The model has been applied to the understanding of chronic pain and has served as the basis for extensive research into chronic orofacial pain.7 The stages of the pain experience offered by this model reflect normal mechanisms through which individuals come to experience pain, attempt to make sense of the pain, and adapt to deal with the pain appropriately. These />