Sex, Gender, and Pain: A Review of Recent Clinical and Experimental Findings

Fillingim and Maixner (Fillingim, R.B. and Maixner, W., Pain Forum, 4(4) (1995) 209-221) recently reviewed the body of literature examining possible sex differences in responses to experimentally induced noxious stimulation. Using a 'box score' methodology, they concluded the literature supports sex differences in response to noxious stimuli, with females displaying greater sensitivity. However, Berkley (Berkley, K.J., Pain Forum, 4(4) (1995) 225-227) suggested the failure of a number of studies to reach statistical significance suggests the effect may be small and of little practical significance. This study used meta-analytic methodology to provide quantitative evidence to address the question of the magnitude of these sex differences in response to experimentally induced pain. We found the effect size to range from large to moderate, depending on whether threshold or tolerance were measured and which method of stimulus administration was used. The values for pressure pain and electrical stimulation, for both threshold and tolerance measures, were the largest. For studies employing a threshold measure, the effect for thermal pain was smaller and more variable. The failures to reject the null hypothesis in a number of these studies appear to have been a function of lack of power from an insufficient number of subjects. Given the estimated effect size of 0.55 threshold or 0.57 for tolerance, 41 subjects per group are necessary to provide adequate power (0.70) to test for this difference. Of the 34 studies reviewed by Fillingim and Maixner, only seven were conducted with groups of this magnitude. The results of this study compels to caution authors to obtain adequate sample sizes and hope that this meta-analytic review can aid in the determination of sample size for future studies.

Sex differences in the perception of noxious experimental stimuli: a meta-analysis.

In September 2006, members of the Sex, Gender and Pain Special Interest Group of the International Association for the Study of Pain met to discuss the following: (1) what is known about sex and gender differences in pain and analgesia; (2) what are the "best practice" guidelines for pain research with respect to sex and gender; and (3) what are the crucial questions to address in the near future? The resulting consensus presented herein includes input from basic science, clinical and psychosocial pain researchers, as well as from recognized experts in sexual differentiation and reproductive endocrinology. We intend this document to serve as a utilitarian and thought-provoking guide for future research on sex and gender differences in pain and analgesia, both for those currently working in this field as well as those still wondering, "Do I really need to study females?"

Studying sex and gender differences in pain and analgesia: a consensus report

Consensus report Studying sex and gender differences in pain and analgesia: A consensus report

This paper presents the first estimates of the prevalence and distribution of several types of mouth and face pains for the U.S. adult, civilian population.

Estimated Prevalence and Distribution of Reported Orofacial Pain in the United States

Based on clinical populations, chronic orofacial pain of temporomandibular disorders (TMD) occurs more frequently (range: 2:1 to 9:1) in women than men. The reasons for this difference are not clear. The present study evaluated symptom presentation, sensitivity to pain, personality, and illness behavior in 2 samples of patients suffering with orofacial pain. Also, pain responses were studied in pain-free volunteers, controlling for experimenter-gender effects. The results showed few gender differences based on ratings of chronic or experimental pain, pain-related illness behavior, and personality. The higher ratio of women versus men seeking TMD care is consistent with greater health awareness or interest in symptoms by women than by men.

Analysis of gender effects on pain perception and symptom presentation in temporomandibular pain

The term Costen's syndrome has been used in the dentomedical literature to describe a constellation of craniofacial symptoms. Since some of the same complaints have been reported in patients with "generalized" psychological distress, symptoms associated with the syndrome may not be useful in differential diagnosis of temporomandibular disorders. The present study investigated whether some somatic complaints, particularly tinnitus and dizziness, were pathognomonic in patients with chronic temporomandibular pain. Illness behavior and personality factors were studied for possible interrelationships with these symptoms. Factor analysis revealed that tinnitus and dizziness loaded on separate factors. Tinnitus loaded with nasal stuffiness, tearing, and itching of the eyelids and nose, while dizziness loaded with complaints of altered taste and smell and blurred vision. Neither was consistently related to measures of pain or to indices of illness behavior or somatic focus.

Otalgia and aversive symptoms in temporomandibular disorders.

Panoramic radiographs of the temporomandibular joints of patients with orofacial pain were examined for evidence of pathology by three different groups of four dental specialists and by a group of four general dentists. Bone scans of the same joints were used as the "gold standard" for identification of disorder and indicated a low rate of correct readings by the four professional groups. When the symptomatic side of the complaint was used as the gold standard, there was no statistically significant association with the bone scan observations. Comparative analysis of other patient symptoms showed little agreement with panoramic radiographs and scintigraphs. Reliability estimates may be highly variable, even among clinical experts. These results show that neither radiologic technique would be definitive for diagnosis of TM disorders.

Interexaminer comparison of bone scintigraphy and panoramic radiography of temporomandibular joints: Correlation with signs and symptoms

joints of patients with orofacial pain were examined for evidence of pathology by three different groups of four dental specialists and by a group of four general dentists. Bone scans of the same joints were used as the "gold standard" for identification of disorder and indicated a low rate of correct readings by the four professional groups. When the symptom- atic side of the complaint was used as the gold standard, there was no statistically significant association with the bone scan observations. Comparative analysis of other patient symptoms showed little agreement with panoramic radiographs and scintigraphs. Reliability estimates may be highly variable, even among clinical experts. These results show that neither radiologic technique would be definitive for diagnosis of TM disorders. (J PROSTHET DENT 1992;67:246-51.)

Walter G. Harrington

Papers

Analysis of gender effects on pain perception and symptom presentation in temporomandibular pain

Otalgia and aversive symptoms in temporomandibular disorders.

Interexaminer comparison of bone scintigraphy and panoramic radiography of temporomandibular joints: Correlation with signs and symptoms

iner comparison of bone scintigraphy oramic radiography of temporomandibular j with signs and symptoms