This Article Abstract Figures Only Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Epker, J. Articles by Gatchel, R. J. Search for Related Content PubMed PubMed Citation Articles by Epker, J. Articles by Gatchel, R. J. Related Collections Dental Stress and Coping

Coping Profile Differences in the Biopsychosocial Functioning of Patients With Temporomandibular Disorder

From the Department of Psychiatry (J.E., R.J.G.), Division of Psychology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas.

Address reprint requests to: Robert J. Gatchel, PhD, Department of Psychiatry, Division of Psychology, University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Blvd., Dallas, TX 75235-9044.

	ABSTRACT

TOP ABSTRACT INTRODUCTION METHODS RESULTS DISCUSSION CONCLUSIONS ACKNOWLEDGMENTS REFERENCES

 
OBJECTIVE: The objective of this study was to evaluate whether biopsychosocial functioning differences exist between samples of patients with temporomandibular disorder (TMD) who differ in coping profiles as assessed by the Multidimensional Pain Inventory.

METHODS: A total of 322 patients who presented with TMD were administered a comprehensive biopsychosocial assessment battery, and the acute or chronic status of their disorder was determined. A follow-up evaluation was conducted 6 months later to determine the status of their pain.

RESULTS: TMD patients with dysfunctional and interpersonally distressed coping profiles demonstrated more acute and chronic psychosocial difficulties than patients with adaptive coper profiles. The data also suggest that having a dysfunctional/distressed coping profile on the Multidimensional Pain Inventory has some predictive value in determining the likelihood of developing chronicity in the absence of treatment.

CONCLUSIONS: The presence of a dysfunctional/distressed coping profile in patients with TMD is likely to provide clinicians with important information about the biopsychosocial functioning of those patients, which, in turn, will help to determine the most effective treatment modalities to use with TMD patients.

Key Words: temporomandibular disorders • biopsychosocial functioning • Multidimensional Pain Inventory • copingprofiles • adaptive coper • dysfunctional/distressed coper

Abbreviations: BDI = Beck Depression Inventory; CPI = characteristicpain intensity; DSM-IV = Diagnostic and Statistical Manualof Mental Disorders, fourth edition; GCPS = graded chronicpain scale; MMPI-2 = Minnesota Multiphasic PersonalityInventory-2; MPI = Multidimensional Pain Inventory; RDC= Research Diagnostic Criteria; SCID = StructuredClinical Interview for DSM-IV diagnosis; TMD =temporomandibular disorder.

	INTRODUCTION

TOP ABSTRACT INTRODUCTION METHODS RESULTS DISCUSSION CONCLUSIONS ACKNOWLEDGMENTS REFERENCES

 
Temporomandibular disorders (TMDs) are characterized as a heterogeneous array of psychophysiological disorders associated with the temporomandibular joint. Symptoms include any or all of the following: pain, joint sounds (clicks, popping, or crepitus) during mastication and opening, and restriction of mandibular movements (1). TMD is often considered a psychophysiological disorder because of the apparent role of the psychological-physical interface, with psychosocial factors such as stress, anxiety, and depression influencing the presentation of TMD symptoms and their severity. Researchers have used numerous methods to investigate these psychosocial factors, including diagnostic interviews, the MMPI-2, and the RDC for TMD (2).

Although most clinicians are familiar with the MMPI-2 and diagnostic interviews, they are likely not as familiar with the RDC, which is seen primarily in the dental and TMD pain literature. The RDC is a dual-axis approach to classifying TMD from both a physiological and psychosocial perspective. Axis I of the RDC is devoted to clinical diagnosis reflecting physical status, and axis II pertains specifically to psychosocial classification. RDC axis I clinical TMD diagnoses are divided into three groups: group I, muscle disorders; group II, disk displacements; and group III, a combination of both muscle and joint displacement disorders. These subgroups of TMD are diagnosed through an examination that includes physical measurements of the jaw and facial area, mandibular range of motion, identifying temporomandibular joint sounds, and manual palpation of extraoral and intraoral muscles. According to this diagnostic system, the number of diagnoses an individual receives can range from a minimum of 0 (no diagnosable musculoskeletal disorders) to a maximum of 5 (one muscle diagnosis plus one diagnosis from groups II and III for each joint). Although it is possible for a clinician to detect five different musculoskeletal disorders, the presence of three or more such disorders is rare (2).

RDC axis II includes primarily three components: a GCPS, measures of depression, and number of nonspecific physical symptoms. The GCPS ranges from 0 to IV and provides a qualitative index for assessing the psychosocial impact of chronic pain. It consists of two primary components: characteristic pain intensity (CPI) and disability. CPI is defined as the mean of visual analog scale scores for "pain right now," "worst pain," and "average pain." Disability is measured by the extent of pain-related interference with daily activities and number of lost activity days (ie, days unable to go to work or school or to attend to household responsibilities) attributed to TMD pain. GCPS scores, or grades, are a function of both the CPI and disability scores, with functional TMD defined as grades I and II, which is indicative of no significant disability due to TMD. Dysfunctional chronic pain is defined as grades III and IV on the GCPS.

The Depression scale and the Nonspecific Physical Symptoms scale are derived from specific items of Symptom Checklist-90 Revised (3). For each scale, the raw mean score is calculated by adding all item scores for that scale and dividing by the number of items answered. These are then classified as either normal, moderate, or severe, depending on the number of symptoms the subject endorses.

As will be shown, the literature on chronic pain is replete with demonstrations of the psychosocial distress and impairment associated with chronic TMD. One approach to this phenomenon has involved comparing levels of psychopathology between patients with chronic TMD and individuals without chronic TMD. Studies that have used structured interviews for assessment report a higher prevalence of clinical disorders and personality disorders among patients with chronic TMD, compared with patients with acute TMD and population norms (4, 5). Research utilizing questionnaires has demonstrated similar results, with chronic TMD samples typically showing higher elevations on the MMPI-2 than healthy patients (6) and greater pain severity and pain-related impairment on the RDC than patients without chronic TMD (2, 7).

Another questionnaire that has received much attention with chronic pain patients is the MPI (8). The MPI is a self-report measure developed to assess chronic pain patients’ experience of pain from a cognitive-behavioral perspective. The benefits of the MPI include its brevity, orientation in cognitive-behavioral theory, empirical derivation, and a normative database of chronic pain patients. The factor structure and psychometric properties have been replicated in numerous studies conducted in the United States, Germany, Sweden, and The Netherlands. After establishing the reliability and validity of the MPI, Turk and Rudy (9) used cluster analyses to generate profile classifications that divide patients into groups on the basis of significant differences in their responses to the 12 scales comprising the MPI. In addition, they demonstrated the external validity of these profiles by comparing patients with different profiles on other psychosocial measures and with different chronic pain syndromes, including TMD (10).

There are three primary MPI-based groups, or profile types, labeled "dysfunctional," "interpersonally distressed," and "adaptive coper." Compared with the other two groups, dysfunctional patients characteristically display greater severity of pain, higher levels of affective distress, lower activity levels, and greater pain-related interference in their lives. Interpersonally distressed patients are individuals who report that their significant others are not very supportive of them. Patients in the adaptive coper group typically report less pain severity, lower levels of affective distress, higher activity levels, and less pain-related interference in their lives than dysfunctional and interpersonally distressed patients. Jamison et al. (11) investigated the external validity of this three-profile classification system of the MPI. Although their results confirmed a high degree of external validity for the MPI, the authors also noted that the dysfunctional and interpersonally distressed groups were similar on some external measures and that they demonstrated significantly greater levels of psychosocial distress than patients with the adaptive coper profile.

The MPI has become well established as a useful tool in the assessment of patients with chronic pain conditions, such as TMD, low back pain, cancer, and fibromyalgia (12). Some studies have investigated the implications for treatment outcome in TMD (13, 14), whereas others have used the MPI profile classification of TMD patients to demonstrate significant differences on psychological measures, such as the MMPI-2 (15). However, there remains a paucity of literature investigating potential differences between MPI styles across multiple biopsychosocial measures in populations of patients with TMD pain. The unique focus of the current study, therefore, was to determine whether such biopsychosocial differences exist between samples of TMD patients who were grouped on the basis of the classification system of the MPI. Although several studies have demonstrated significant differences between MPI coping groups on one or two psychosocial measures, few, if any, have done so with a combination of well-validated physiological and psychosocial measures within the same sample of TMD patients. The demonstration of such differences would provide evidence that clinicians could utilize the MPI instead of other psychosocial measures in any effort to assess the aforementioned psychosocial domains.

TMDs have received increased attention by behavioral scientists during the past two decades because of the importance of psychosocial factors in these physiological disorders. Moreover, Fricton and Schiffman (16) have estimated that the annual cost of treating chronic pain approximates $80 billion, with 40% of the cost attributed to craniomandibular pain, including that of TMD. Thus, more investigations of this chronic pain disorder, such as the present study, are needed to develop the most effective assessment and treatment programs for this high-cost healthcare problem.

	METHODS

TOP ABSTRACT INTRODUCTION METHODS RESULTS DISCUSSION CONCLUSIONS ACKNOWLEDGMENTS REFERENCES

 
Subjects
Three hundred twenty-two patients who presented with TMD and who were between 18 and 65 years of age participated in the initial assessment phase of this study. Participants were referred by dentists and oral surgeons of the Dallas/Fort Worth, Texas, area and the Baylor College of Dentistry, Dallas, Texas. In addition, flyers were posted at local universities, and advertisements were placed in local newspapers to recruit subjects. All patients were diagnosed as having TMD on the basis of the RDC axis I criteria of pain and tenderness of the muscles of mastication and/or limited mandibular movements within the temporomandibular joint. Patients were considered to have chronic TMD if they continued to have TMD pain at a 6-month follow-up assessment. All patients were paid $20 for their participation.

Procedure
Clinical psychology research personnel reviewed the purpose and procedure of the study with patients, and informed consent was obtained. After patients signed the informed consent form, they completed a payment voucher and the following instruments: General Information Questionnaire, History Questionnaire for the RDC (2), the BDI (17), the MPI, and the MMPI-2. All patients were then interviewed using SCID I and II (18) for DSM-IV (19) to determine DSM-IV axis I clinical disorders and axis II personality disorders. They were also asked to sign an additional consent form allowing the structured interview to be recorded on cassette. Audiocassettes were randomly selected for review by senior research personnel to evaluate interrater reliability of DSM-IV diagnoses. After the interview, the patient was physically examined using the TMD-RDC examination form. The TMD-RDC examiners were initially trained and periodically "calibration-checked" by an oral surgeon knowledgeable of the RDC. The initial assessment took approximately 2.5 hours. In addition, monthly meetings were held with a psychiatrist knowledgeable of DSM-IV and the scoring of the SCID to clarify any diagnostic issues.

On completion of the initial assessment, the determination of the patient’s TMD status (acute or chronic) was made. Acute TMD classification depended on whether the date that the patient first sought treatment was within 6 months of the initial assessment. Patients who had never sought treatment for TMD were considered to have acute TMD. Patients who had first sought treatment more than 6 months before the study’s initial assessment were considered to have chronic TMD and had the opportunity to participate in a separate treatment outcome study. The decision to use the patient’s first visit to a healthcare professional as a reference point for determining chronicity was based on the belief that this most closely resembles the "real world" of patient behavior and provides a more accurate determination of a concrete starting point for potential chronicity progression. For example, it is not uncommon for patients to respond to inquiries about when their pain began with a statement such as "since high school" or "many years ago." These responses are vague and do not allow for accurate quantitative assessment. However, patients are much more specific with regard to the first time they sought assistance with such a condition. In addition, it could be argued that seeking treatment represents a subjective "critical mass" for the patient, suggestive of having reached a threshold of acceptable tolerance.

Research personnel contacted all acute TMD patients by telephone at 3- and 6-month intervals after the evaluation. This contact consisted of a brief interview, using questions from the History Questionnaire, which provided CPI and GCPS scores. At the 6-month interval, patients whose CPI score was <15 were considered to have nonchronic TMD, whereas those with scores 15 were considered to have chronic TMD.

	RESULTS

TOP ABSTRACT INTRODUCTION METHODS RESULTS DISCUSSION CONCLUSIONS ACKNOWLEDGMENTS REFERENCES

 
Demographic Variables
Consistent with the findings of Jamison et al. (11), a comparison of the dysfunctional and interpersonally distressed groups, using analysis of variance, t tests, and ² analyses, demonstrated that the two were quite similar across most demographic (eg, age, gender, race, marital status), physiological (ie, presence of a muscle disorder), and psychosocial indices (ie, frequency of DSM-IV diagnoses, BDI scores, and RDC depression and limitations scores) (see Table 1). Multivariate analyses of the MMPI-2 scores indicated a significant scale difference between the two groups (Hotelling’s T² = 0.29, approximate F(13,127) = 2.80, p = .002). Subsequent univariate analyses demonstrated that there was a significant group effect for scale 1 (F(1,139) = 10.14, p = .002) and scale 3 (F(1,139) = 4.92, p = .028) (see Table 2). Thus, among all demographic, physiological, and psychosocial variables, the only statistically significant differences between the dysfunctional and interpersonally distressed groups were on scales 1 and 3 of the MMPI-2, GCPS scores, and nonspecific physical symptoms on axis II of the RDC.

Comparisons of the adaptive coper and dysfunctional/distressed groups on demographic variables demonstrated no statistically significant differences for gender (²(1) = 3.65 (N = 322), p = .06), marital status (²(4) = 4.86 (N = 322), p = .30), or race (²(3) = 1.11 (N = 322), p = .77). However, as will be shown, comparisons between the groups demonstrated that the two were significantly different across most psychosocial indices, including many scales of the MMPI-2, axes I and II of the RDC, and frequency of SCID diagnoses.

MMPI-2 and RDC Variables¹
Analysis of variance revealed that the patients with a dysfunctional/distressed profile evidenced significantly higher scores than those with the adaptive coper style on each of the clinical scales of the MMPI-2 except scale 5 (see Table 3). In particular, the dysfunctional/distressed group produced elevated scores on scales 1 and 3 to a clinically significant degree (ie, t 65) and yielded a "conversion V" pattern (see Figure 1).

View larger version (13K): [in this window] [in a new window]   Fig. 1. MMPI-2 profiles of patients with adaptive coper and dysfunctional/distressed profiles on the MPI.

SCID Variables
Findings from the SCID were similar, with the dysfunctional/distressed group being diagnosed with significantly more axis I clinical disorders (t(1,310) = -5.64, p < .001) and axis II personality disorders (²(6) = 19.21 (N = 322), p < .001) than the adaptive coper group. Specifically, patients within the dysfunctional/distressed group were diagnosed with a significantly greater number of current mood disorders (²(2) = 23.72 (N = 322), p < .001), current anxiety disorders (²(6) = 20.60 (N = 322), p = .002), current eating disorders (²(1) = 4.11 (N = 322), p = .043), current psychotic disorders (²(1) = 3.98 (N = 322), p = .046), and current somatization disorders (²(3) = 21.92 (N = 322), p < .001). There was, however, no significant difference between the dysfunctional/distressed group and the adaptive coper group in terms of the number of substance abuse/dependence diagnoses. In addition, with regard to axis II disorders, 23.5% of the adaptive copers, compared with 41% of the dysfunctional/distressed patients, were diagnosed with one or more personality disorders, whereas 6.0% of the patients in the former group, compared with 16.7% of the latter group, had two or more such diagnoses.

Although not a primary focus of this study, it is noteworthy that among patients with acute TMD at initial presentation (N = 115), a significant percentage of those with dysfunctional/distressed profiles developed chronic TMD (83%) compared with the adaptive coper patients (48.4%) (²(1) = 14.94 (N = 115), p < .001). Finally, consistent with the notion that patients who possess a dysfunctional/distressed profile differ in significant physiological and psychosocial ways from patients with an adaptive coper profile, a logistic regression analysis revealed that the presence of a myofascial pain disorder, scores on scales 3 and 8 of the MMPI-2, BDI scores, RDC limitations, and CPI scores significantly differentiated between coping style groups, with 86% classification accuracy among the patients with acute TMD (see Table 4).

	DISCUSSION

TOP ABSTRACT INTRODUCTION METHODS RESULTS DISCUSSION CONCLUSIONS ACKNOWLEDGMENTS REFERENCES

From a physiological standpoint, patients with a dysfunctional or interpersonally distressed profile were more likely to be diagnosed with a muscle disorder or a combination of muscle disorders and joint displacement disorders than patients who were adaptive copers. In addition, data from axis II of the RDC provided additional evidence of the psychosocial difficulties experienced by patients with either a dysfunctional or interpersonally distressed profile, with these patients reporting a greater number of both depressive symptoms and nonspecific physical complaints than did the adaptive copers.

The demonstration of greater psychological difficulties was also evident in the frequency of both axis I and axis II diagnoses obtained through utilization of the SCID. Patients with either a dysfunctional or interpersonally distressed profile on the MPI were diagnosed with significantly more clinical disorders than adaptive copers across every major category of axis I of DSM-IV, except for substance abuse/dependence. The same was true for more long-standing personality patterns, as revealed by a greater frequency of axis II diagnoses. This is further evidence that these TMD patients (ie, those with dysfunctional or interpersonally distressed coping styles) have significant acute and chronic problems that manifest in the form of psychological distress and suggests a high potential for maladaptive behavior among these individuals. Finally, the data suggest that having a dysfunctional or interpersonally distressed coping style increases the likelihood of the condition becoming chronic (ie, causing prolonged pain and disability) in the absence of treatment. For example, among the subset of patients with acute TMD at initial presentation, a substantial majority of those from the dysfunctional/distressed group developed chronic TMD, compared with less than half of the patients with an adaptive coper profile.

	CONCLUSIONS

TOP ABSTRACT INTRODUCTION METHODS RESULTS DISCUSSION CONCLUSIONS ACKNOWLEDGMENTS REFERENCES

 
The group of patients with either a dysfunctional or interpersonally distressed profile on the MPI demonstrated significantly more physiological, psychological, and social impairment than patients with an adaptive coper profile across the various biopsychosocial measures in this study. This suggests that the presence of such a "dysfunctional/distressed" profile in patients with TMD is likely to provide clinicians with important information about functioning across a variety of domains. In addition, clinicians and researchers interested in assessing biopsychosocial functioning in this population may benefit from use of the MPI instead of more traditional measures, such as the MMPI-2 and administration of a SCID for determining axis I and axis II diagnoses. The MPI has the following advantages: it is shorter, the items have high face validity, there is a great deal of normative data on chronic pain patients, and, perhaps most importantly, the MPI was developed and standardized with samples of chronic pain patients.

The presence of either a dysfunctional or interpersonally distressed profile on the MPI is indicative of impairment in multiple areas of functioning and may interfere with the efficacy of any standard medical or dental treatment. Several studies have begun to address such problems. For example, Rudy et al. (13) examined the differential response of TMD patients classified within the three MPI profiles to a conservative treatment (intraoral appliance, biofeedback, and stress management). They found that patients with dysfunctional styles demonstrated the greatest amount of change on indices of pain intensity and depression. In a similar study, Turk et al. (14) evaluated the efficacy of treatments tailored to TMD patients with dysfunctional profiles. They determined that these TMD patients demonstrated prolonged improvements in response to the protocol that included a cognitive therapy component. Studies such as these demonstrate that the MPI can be a useful tool for assessing TMD patients and then determining the most effective treatment modalities. Additional implications for type of MPI coping style on medical/dental and psychosocial interventions in patients with TMD continue to be important topics for future research.

	ACKNOWLEDGMENTS

TOP ABSTRACT INTRODUCTION METHODS RESULTS DISCUSSION CONCLUSIONS ACKNOWLEDGMENTS REFERENCES

 
This research was supported in part by Grants R01 DE10713 and K02 MH01107 from the National Institutes of Health. The authors thank the following dentists for referring patients for participation in this study: Drs. Stacy Cole, Rick Harper, Charles Holt, William Langston, James Moore, Richard Riggs, Douglas Sinn, Keith Thornton, and Gill Triplett.

Received for publication January 25, 1999.

Revision received July 12, 1999.

	REFERENCES

TOP ABSTRACT INTRODUCTION METHODS RESULTS DISCUSSION CONCLUSIONS ACKNOWLEDGMENTS REFERENCES

 

1. Glaros AG, Glass EG. Temporomandibular disorders. In: Gatchel RJ, Blanchard EB, editors. Psychophysiological disorders: research and clinical applications. Washington DC: American Psychological Association; 1993. pp. 299–356.
2. Dworkin SF, LeResche L. Research diagnostic criteria for temporomandibular disorders: review, criteria, examinations and specifications, critique. J Cranio Dis 1992; 6: 302–55.
3. Derogatis LR. SCL-90-R manual. Baltimore: Clinical Psychometric Research; 1977.
4. Gatchel RJ, Garofalo JP, Ellis E, Holt C. Major psychological disorders in acute and chronic TMD: an initial examination. J Am Dent Assoc 1996; 127: 1365–74.[Abstract/Free Full Text]
5. Kinney RK, Gatchel RJ, Ellis E, Holt C. Major psychological disorders in chronic TMD patients: implications for successful management. J Am Dent Assoc 1992; 123: 49–54.[Abstract]
6. Schumann NP, Zweiner U, Nebrich A. Personality and quantified neuromuscular activity of the masticatory system in patients with temporomandibular joint dysfunction. J Oral Rehab 1988; 15: 35–47.[Medline]
7. Dworkin SF, Von Korff MR, LeResche L. Multiple pains and psychiatric disturbance: an epidemiologic investigation. Arch Gen Psychiatry 1990; 47: 239–44.[Abstract]
8. Kerns RD, Turk DC, Rudy TE. The West Haven-Yale Multidimensional Pain Inventory (WHYMPI). Pain 1985; 23: 345–56.[Medline]
9. Turk DC, Rudy TE. Toward an empirically derived taxonomy of chronic pain patients: integration of psychological assessment data. J Consult Clin Psychol 1988; 56: 233–8.[Medline]
10. Rudy TE, Turk DC, Zaki HS, Curtin HD. An empirical taxometric alternative to traditional classification of temporomandibular disorders. Pain 1989; 36: 311–20.[Medline]
11. Jamison RN, Rudy TE, Penzien DB, Thomas H. Cognitive-behavioral classifications of chronic pain: replication and extension of empirically derived patient profiles. Pain 1994; 57: 277–92.[Medline]
12. Turk DC, Okifuji A. Evaluating the role of physical, operant, cognitive, and affective factors in the pain behaviors of chronic pain patients. Behav Modif 1997; 21: 259–80.[Abstract]
13. Rudy TE, Turk DC, Kubinski JA, Zaki HS. Differential treatment responses of TMD patients as a function of psychological characteristics. Pain 1995; 61: 103–12.[Medline]
14. Turk DC, Rudy TE, Kubinski JA, Zaki HS, Greco CM. Dysfunctional patients with temporomandibular disorders: evaluating the efficacy of a tailored treatment protocol. J Consult Clin Psychol 1996; 64: 139–46.[Medline]
15. Etscheidt MA, Steiger HG, Braverman B. Multidimensional Pain Inventory profile classifications and psychopathology. J Consult Clin Psychol 1995; 51: 29–36.
16. Fricton JR, Schiffman EL. Epidemiology of temporomandibular disorders. In: Fricton JR, Dubner R, editors. Orofacial pain and temporomandibular disorders. New York: Raven Press; 1995. p. 1–14.
17. Beck AT, Ward CH, Mendelson M, Mock J, Erbaugh J. An inventory for measuring depression. Arch Gen Psychiatry 1961; 56: 53–63.
18. Spitzer RL, Williams JB, Gibbon M, First N. Structured Clinical Interview for DSM-IV. New York: New York State Psychiatric Institute; 1995.
19. DMS-IV. Diagnostic and statistical manual of mental disorders. 4th ed. Washington DC: American Psychiatric Association; 1994.

This article has been cited by other articles:

				J. A. TURNER and S. F. DWORKIN Screening for psychosocial risk factors in patients with chronic orofacial pain: Recent advances J Am Dent Assoc, August 1, 2004; 135(8): 1119 - 1125. [Abstract] [Full Text] [PDF]

				R. J. Gatchel Author's response J Am Dent Assoc, April 1, 2001; 132(4): 425 - 426. [Full Text] [PDF]

This Article Abstract Figures Only Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Epker, J. Articles by Gatchel, R. J. Search for Related Content PubMed PubMed Citation Articles by Epker, J. Articles by Gatchel, R. J. Related Collections Dental Stress and Coping