|The biobehavioral model of pain is the foundation for clinical assessment and pain management.|
|Core biobehavioral principles include multifactorial assessment, the role of learning history, and the interplay between biologic and psychologic factors.|
|Screening strategies for biobehavioral risk factors include pain, distress, and pain-related disability as well as pain history for red and yellow flags for patient care.|
|A comprehensive evaluation of biobehavioral factors includes pain location and intensity, pain-related disability, psychologic distress, sleep dysfunction, posttraumatic stress disorder (PTSD), alcohol or drug use, limitations in use and movement, and parafunctional activities.|
|The most common psychiatric disorders in the orofacial pain practice include depression, anxiety (including PTSD), somatization, and personality disorders.|
|Following referral to mental health care providers, the clinician should expect a comprehensive evaluation, a treatment plan targeting skills acquisition, and feedback in a timely manner.|
|Integrated care among health care professionals is the standard of care.|
Scientific advances in understanding modulatory control of ascending and descending neural circuits involved in pain processing, including the role of glial cells, have highlighted the important roles that variables such as emotion, cognition (including attention and expectation), and behavior play in pain transmission, awareness, and suffering. The fact that emotions, cognitions, and behaviors can facilitate or inhibit orofacial pain requires the adoption of a biobehavioral model of disease. Behavioral factors encompass a broad spectrum of behavioral science theory (eg, principles of learning, interpersonal processes, family systems, social learning) and techniques for change (eg, relaxation training, interpersonal psychotherapy, biofeedback, cognitive therapy, breathing training). When behavioral factors are discussed in the context of how they contribute to the functioning of biologic systems, it is appropriate to use the term biobehavioral.
As discussed in chapter 1, Engel1 noted that the biomedical model, with its focus on pathobiology, does not fully explain the development of disease states. Therefore, he introduced the term biopsychosocial to describe the complex interactions between biology, psychologic states, and social conditions that bring about and/or maintain (dys)function. The term biobehavioral is parallel to the word biomedical, and both concepts are subsumed in Engel’s biopsychosocial model. While the term biopsychosocial is often used because it is more globally accepted, biobehavioral calls attention to behavioral factors as they contribute to the functioning of biologic systems.
Adopting the biobehavioral model of orofacial pain requires that linear, unidirectional models of causation and of treatment be replaced by a bidirectional approach to treatment. Whether the practitioner provides dental or psychologic treatment, a mechanistic linear model (eg, identify the cause, treat the cause, observe recovery) for understanding orofacial pain conditions is an incomplete model that will yield incomplete, inappropriate, and misdirected clinical care. Unless behavioral, psychologic, and social dimensions of a patient’s presenting complaints and current adaptive strategies are addressed in the treatment plan, effective management of the pain condition will not likely be achieved, especially in chronic pain conditions. This multidisciplinary philosophy of treatment does not necessarily require a multispecialty clinic with dentists, psychologists, physical therapists, and physicians. It rather requires a worldview by individual practitioners themselves that embraces the biobehavioral perspective, from which appropriate integration of diverse treatment strategies can be implemented instantaneously as patient circumstances, the symptom picture, and the case conceptualization evolve over the course of treatment as well as over the course of the disorder.
Pain is a complex phenomenon influenced by multiple biologic and psychologic factors. Nociception that reaches thalamocortical-basal ganglia circuitry in the brain evokes the sensation of pain. However, because pain is a personalized perceptual experience, it can be modified by factors other than the intensity of the nociceptive stimuli themselves. For example, excitatory factors that could amplify the pain experience include fear, anxiety, attention, and expectations of pain. Conversely, self-confidence, positive emotional states, relaxation, and beliefs that the pain is manageable may reduce reports of pain.2 Importantly, these modifying factors not only affect the perceptual aspects of what defines pain at any moment for an individual but also contribute to descending modulation. These examples highlight the concept that nociception is the result of a dynamic balance between peripheral input and ongoing central nervous system (CNS) regulation of that input at the level of the dorsal horn entry into the CNS.
The biobehavioral approach to orofacial pain disorders involves assessing not only the underlying behavioral and psychologic disturbances but also the physiologic disturbances that may be associated with the pain condition and helping the patient learn new skills for managing these disturbances. The needed skill acquisition can range from simple to complex; the latter may involve referral to a mental health care professional. Effective symptom management, both physical and psychologic, may be elusive for many patients, especially for those whose pain has become chronic (eg, lasting longer than 3 to 6 months). These patients may have adopted coping patterns to maintain some level of functioning. However, sometimes these efforts at coping, while perhaps successful in the early stage of an illness, contribute in later stages to the development of maladaptive patterns that extend beyond the pain condition and into multiple aspects of daily life. For example, a patient who stops engaging in pleasurable daily activities because of pain upon movement may be prone to depression. When maladaptive patterns emerge, it is important that the clinician be prepared to recognize and manage them appropriately, because failure to do so will likely prolong suffering (an individual’s negative emotional reaction to pain) and prevent effective symptom management. It is also possible that maladaptive coping patterns were in practice before the pain condition’s onset and may have intensified the problem. Such coping patterns may also be associated with a variety of psychopathologic conditions, which are discussed in later sections of this chapter. The psychopathology may be actively preexisting, it may be subclinical until the onset of an intractable problem, or it may be emergent in response to new illness.
The biobehavioral perspective introduces a model whereby the assessment process includes an interview component that focuses not only on the biologic aspects of the presenting condition but also on the psychosocial processes, thus providing a broader perspective from which to understand and conceptualize treatment for a patient’s presenting pain symptoms. It is rare that pain reports are based solely on psychologic or so-called psychogenic factors. It is equally rare, however, to find that pain, especially chronic pain of at least 3 to 6 months’ duration, is not influenced by psychologic factors to some degree. Psychologic factors may also account for the individual differences in response to similar levels of pain. Because there can be substantial individual variability in response to painful conditions, the reported intensity of pain may not necessarily be linked to an individual’s expressed reaction to the pain. It is common for both clinicians and patients to be confused regarding the relative nature of reported pain intensities; one reaction is to dismiss such reports as “subjective” (often with the intended meaning of “irrelevant” or “imaginary”). The relative nature of pain intensity does not diminish its validity; rather, it requires active interpretation to make it meaningful. It is the task of the clinician to understand the patient’s story and to make sense of his or her pain reports.
It is often difficult to predict outcomes for the treatment of many chronic pain conditions without knowing the full psychosocial history. Patients can be helped considerably by learning to manage their orofacial pain conditions for extended periods of time, but ongoing biobehavioral issues may either promote or prevent the use of such skills for symptom management, leading to the common pattern of remission-relapse. The reality is that it is not a matter of “curing” pain but learning to manage pain with the physical and psychologic tools developed and refined through the practice of science. It is helpful to remind ourselves and our patients that finding the dynamic balance of input and CNS control at the dorsal horn is a long-term goal. Among the kinds of factors that often contribute to relapse, stress reactivity is most likely one of the most difficult skills to master; here, allostasis—another example of a dynamic balance among systems—is a central concept for patients to work toward experiential understanding.
In recognition of these complexities, Dworkin et al3–6 proposed several models for capturing the dimensions of pain over time. Inherent in these models is the simultaneous consideration of both physical status and biobehavioral status for every patient. For assessment of both physical and biobehavioral status to be equally useful in the clinic, reliable assessment methods are needed for the physical examination (using an operationalized framework) and the biobehavioral screening (using standardized, validated instruments). Extensive research has demonstrated the value of these core components in terms of clinical trials and modeling disease progression and response to treatment.6–9 More recently, research has demonstrated the reliability and validity of structured assessments6,10–12 upon which the current versions of diagnosis and biobehavioral assessment are emerging.10–12 A final recent development has been the Orofacial Pain Prospective Evaluation and Risk Assessment (OPPERA) Study, which places due recognition on the genetic underpinnings of neuroplasticity, biobehavioral factors, and their interactions in shaping risk for developing a pain disorder.13 In our view, the biobehavioral model for clinical care of persons with pain disorders is intended to encompass all aspects of neurobiology associated with health and disease; when a patient tells us that he is depressed, he is informing us of the state of his brain and how the resultant behavior is recursively further shaping that brain state. While that information is gathered via self-report instruments and interviews, the information is no less valuable than that obtained from a clinical examination, assuming that reliable and valid methods are used for the assessment.
To reflect the recognition of behavioral and psychologic dimensions in the etiology of orofacial pain, a multiaxial nosology for these disorders has been created and implemented on a broad scale. Similar to the development of axial coding systems for psychiatric disorders forwarded by the American Psychiatric Association14 and pain disorders developed by the International Association for the Study of Pain, the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) were developed by a group of scientists and clinicians in 1992.5 Axis I focuses on the physical nature of the disease and includes the variety of orofacial pain conditions discussed in earlier chapters of this text. Axis II focuses on the patient’s adaptation to the pain experience and pain-related disability that may result from the pain itself and assesses the extent to which the orofacial pain condition is associated with psychologic distress, disability, or impairment in functioning (significant disruption in normal activities), based on the use of standardized and validated assessment methods (Table 12-1).
|Table 12-1 Axis II assessment instruments|
|Area of concern||Instrument||No. of
|Pain location||Pain mannikin drawing||1||Yes||Yes|
|Pain intensity||Graded Chronic Pain Scale||3||Yes||Yes|
|Pain disability||Graded Chronic Pain Scale||4||Yes||Yes|
|Sleep||Pittsburgh Sleep Quality Index||18||Yes|
|Limitation||Jaw Functional Limitation Scale||8 or 20||Yes||Yes|
|PHQ-4—Patient Healthcare Quiestionnaire 4; SCL-loR—Symptom Checklist lo-Revised; PROMIS—Patient Reported Outcome Measures Information System; AUDIT-C—Alcohol Use Disorders Identification Test.|
The RDC/TMD Axis II was an attempt to codify the emotional sequelae and functional limitations that accompany chronic orofacial pain conditions and to determine whether there is need for referral of patients to appropriate providers (ie, psychiatrists, clinical psychologists) for formal assessment of cognitive, emotional, and behavioral sources of disruption in normal functioning due to or associated with the pain problem.
Recently, an international consensus workshop6 agreed on the minimal basic components that should be assessed for a sufficient biobehavioral evaluation; these include pain, physical function, overuse behaviors, comorbid physical symptoms, and emotional and psychosocial function. Another workshop15 clarified the distinction between what is needed for initial screening, what is needed for more comprehensive assessment in a clinical setting, and what might be of value in a specialist biobehavioral setting.
It is the clinician’s role to judge the level of complexity of the patient’s clinical presentation and to decide whether additional resources outside the scope of the dental practice should be included in the treatment plan. The task is not to develop a psychiatric diagnosis (eg, major depression secondary to the loss of a spouse) but to develop a treatment plan that includes appropriate care for the unique features of the presenting patient. This screening can be augmented by the use of various self-report instruments that have demonstrated reliability and validity for use in identifying potential psychologic dysfunction that can interfere with pain management from the physical medicine perspective. Standardized instruments provide the clinician with an actuarial approach to decision-making rather than relying solely on clinical judgments based on a more limited source of information from the initial interview. Health care providers have difficulty in making accurate judgments of pain patients’ psychologic status.16 More specifically, Oakley et al17 reported that clinicians tend to overreport psychopathology. These results suggest that the use of screening instruments may help improve the accuracy of clinical decision-making in the orofacial pain setting.
Based on practice recommendations, recent findings from the RDC-TMD Validation Project, and a subsequent consensus workshop for developing the next diagnostic and evaluation protocol for clinical use, strong agreement has emerged regarding the necessity for clinicians to conduct an assessment of biobehavioral factors in the initial consultation session. In terms of which factors should be evaluated, setting (eg, general dental or medical office, orofacial pain specialist office, research clinic, psychologist office) and purpose (eg, initial screening, more in-depth evaluation by the orofacial pain specialist, comprehensive evaluation by a consulting psychologist) of the evaluation influence to what degree the assessment should be done. The selection of the level of the biobehavioral focus implies that the clinician understands the importance of biobehavioral factors in the patient’s presentation and the context in which the patient evaluations occur. When it comes to the first line of screening, however, the critical dimensions include (1) some means of assessing multiple pain conditions or complaints in addition to the orofacial pain that generated the initial clinical visit, (2) pain intensity and pain-related disability, and (3) psychologic distress.6,10,18–20
One of the strongest and most consistent predictors of onset of a new orofacial pain condition is the presence of other ongoing pain complaints; multiple pain conditions are also a strong predictor of the transition from acute pain to chronic pain in an individual. Presence of multiple pain complaints can be assessed with a drawing of the full human body, front and back, where the patient can note areas of ongoing pain. Other initial strategies for assessing multiple pain conditions include using a checklist or specific questions concerning pain in other regions of the body.
Both the intensity of pain and the impact of the pain on functioning can be obtained with the Graded Chronic Pain Scale (GCPS).21 This brief, seven-item screening instrument includes an assessment of current pain intensity, worst pain intensity, and average pain intensity using a scale of 0 to 10, where 0 represents “no pain” and 10 represents “pain as bad as can be.” When averaged together, these data provide an excellent overall index of pain intensity. The GCPS also includes four questions concerning disability related to the pain. Based on the intensity and disability ratings, patients can be classified into one of five categories, Grades 0 to IV. Grade 0 represents being pain free; Grade I represents low intensity of pain and low disability; Grade II represents high intensity of pain and low disability; Grade III represents moderately limiting disability; finally, Grade IV represents severely limiting disability. Pain intensity is not considered in Grades III and IV. The GCPS is recommended for regular use in the orofacial pain setting, because it is a reliable, valid, and brief screening tool for pain and pain-related disability. High self-rated levels of pain, interference, and impact, along with low ability to control pain, suggest the need for further biobehavioral evaluation and appropriate referral for consultation.21,22
The more common forms of distress presenting in the orofacial pain clinic include depression and anxiety, ranging from mild symptoms to severe disorders.22 Depression and anxiety are described in detail in later sections of this chapter so that the reader has a broader understanding of these conditions within the context of the orofacial pain setting. However, the immediate concern of the clinician is to screen patients and identify those who need further consultation and care by a qualified mental health care provider. While there are a variety of screening instruments, two instruments are discussed here because of their ease of use and reliability.
The Symptom Checklist 90-Revised (SCL-90R)23 provides the clinician with a validated screening instrument for the presence of symptoms reflecting significant psychologic dysfunction. Two of its scales (somatization and depression) were used in the development of the original RDC/TMD guidelines. Its use, however, requires clinician training in administration, scoring, and interpretation that is beyond the scope of this chapter but can be readily obtained through continuing education or other formalized training programs. The SCL-90R is composed of 90 common symptoms of psychopathology grouped into 9 symptom domains (eg, depression, anxiety, etc). Each symptom is rated on a 5-point scale ranging from 0 (“not at all”) to 4 (“extremely”). If any clinical domain scores are greater than one standard deviation above the mean, clinicians should refer the patient to a mental health care provider for a thorough evaluation. The SCL-90R typically requires about 15 minutes for completion and can be completed before the initial face-to-face evaluation. One disadvantage of the SCL-90R is that it is a proprietary instrument and has a cost associated with each administration.
A very brief measure for screening distress is the Patient Health Questionnaire 4 (PHQ-4),24 which assesses both depression and anxiety. The PHQ-4 is a four-item measure that evaluates functioning over the past 2 weeks with a scale ranging from 0, meaning “not at all,” to 3, meaning “nearly every day.” It requires about 1 minute for administration. This brief instrument yields a rating of normal, mild, moderate, or severe distress. Any non-normal rating is an indication for further evaluation by a qualified mental health care provider. This instrument is ideally suited for the screening of distress in the orofacial pain environment.
Several other standardized screening questionnaires are available for depression/anxiety that can enable the clinician to make informed decisions about the need for more extensive diagnostic decision-making and treatment planning.25–27 In clinical settings, the choice of one instrument over another is far less important than knowing the instrument and knowing one’s clinical population in relation to how those patients are distributed across the range of scores from that given instrument.
In addition to depression and anxiety, studies have identified the important roles of sleep disturbances and PTSD as strong predictors of distress and pain in orofacial pain patients.28–31 There are brief, reliable paper-and-pencil screening instruments available to assess sleep (eg, Pittsburgh Sleep Quality Index; Paitient-Reported Outcome Measures Information System [PROMIS] sleep instruments) and PTSD (PTSD Checklist). Many clinicians may find the information from these instruments quite helpful in the evaluation process and treatment planning. Overall, it is important that dentists and other health care clinicians be able to recognize maladaptive coping mechanisms and direct patients to appropriate evaluation and treatment programs to address these dysfunctions. The use of a pain mannikin, GCPS, and the PHQ-4 (or SCL-90R) serves as an acceptable initial minimum screening for all orofacial pain patients to determine who should be referred for further evaluation by qualified mental health care providers.
In addition to pain-relevant biobehavioral constructs, Turner and Dworkin20 noted the value in screening for prolonged and/or excessive use of opiate medications, benzodiazepines, alcohol, and other addictive medications. Clinicians can screen for these problems in the course of their initial evaluation interview. When screening for alcohol use, one reliable instrument is the Alcohol Use Disorders Identification Test (AUDIT-C).32 This three-item questionnaire is a reliable means of identifying whether an individual should be referred for careful evaluation of alcohol use.
Health care providers working with patients with chronic back pain have used a “red flag” (representing a potentially serious condition for which immediate attention is needed) and “yellow flag” (representing potential psychologic or social barriers to full recovery) strategy in the initial evaluation process (Box 12-1). Such a strategy is prudent within the orofacial pain setting as well when it comes to implementing a biobehavioral approach. There are red flags in the psychosocial history of the orofacial pain patient that demand immediate attention and primarily focus on signs of suicide. The most common signs of potential suicide include talking about suicide, either generally or specifically, and/or actual plans for taking one’s own life (suicidal ideation) and hopelessness. There are other warning signs for suicide, including persistent and despairing mood, significant weight loss or gain, change in appetite, withdrawal and social isolation, and change in sleep pattern, all symptoms that are associated with depression as well. Any patient who presents with thoughts about suicide, plans for suicide, or hopelessness should be evaluated as soon as possible by qualified mental health care professionals for risk assessment.
|Box 12-1 Red and yellow flags for referral of orofacial pain patients|
|Red flag → Refer immediately|
|Suicidal thoughts or plans|
|Yellow flag → Proceed with caution and consider referral|
|Alcohol or drug use
Persistent beliefs about pain
Problems in compensation or claims
Time off work
Problems at work
Overprotection from family members
Lack of social support
Chronicity of pain
Discrepancies in findings
Overuse of medications
Inappropriate behavior, expectations, or responsiveness to prior treatment
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