Linda LeResche

Changes in temporomandibular pain and other symptoms across the menstrual cycle

&NA; The objective of this study was to assess changes in levels of clinical temporomandibular (TMD) pain in relation to phases of the menstrual cycle. TMD cases were 35 women not using oral contraceptives (OCs); 35 women using OCs; and 21 men. Controls were 35 normally cycling women without TMD or other chronic pains. Subjects kept daily diaries over three menstrual cycles, reporting average and worst pain, general and premenstrual symptoms. Data were subject‐centered and de‐trended using the residuals from a random‐effects linear regression model. To test for cyclic variation, cycles were standardized to 28 days and data were grouped into 9 periods/cycle (Days 1–3, 4–6,…, 22–24, 25–28). Overall levels of average pain, worst pain and symptoms did not differ across TMD subject groups. For worst pain, multivariate analysis of variance revealed a statistically significant difference across 3‐day periods for normally cycling women with TMD (P=0.011) and for women using OCs (P=0.017). In both groups, TMD pain levels rose toward the end of the cycle and peaked during menstruation. In women not using OCs, there was a secondary pain peak at Days 13–15, around the time of ovulation. This peak was not seen in women using OCs. There was no statistically significant difference over time periods for men (P=0.94). Similar patterns were found for average pain, as well as PMS symptoms and general somatic symptoms. These results suggest that TMD pain in women is highest at times of lowest estrogen, but rapid estrogen change may also be associated with increased pain.

Use of exogenous hormones and risk of temporomandibular disorder pain.

Abstract Temporomandibular disorders (TMD) are common pain conditions that have their highest prevalence among women of reproductive age. The higher prevalence of TMD pain among women, pattern of onset after puberty and lowered prevalence rates in the post‐menopausal years suggest that female reproductive hormones may play an etiologic role in TMD. Two epidemiologic studies were designed to assess whether use of exogenous hormones is associated with increased risk of TMD pain. Both used data from automated pharmacy records of women enrolled in a large health maintenance organization to identify prescriptions filled for post‐menopausal hormone replacement therapies (Study 1) or for oral contraceptives (OCs) (Study 2). Study 1 employed an age‐matched case‐control design to compare post‐menopausal hormone use among 1291 women over age 40 referred for TMD treatment and 5164 controls not referred. After controlling for health services use, the odds of being a TMD case were approximately 30% higher among those receiving estrogen compared to those not exposed (P=0.002); a clear dose‐response relationship was evident. The relationship of progestin use to TMD was not statistically significant. Study 2 used a similar design to examine the relationship of OC use to referral for TMD care, drawing on data from 1473 cases and 5892 controls aged 15–35. Use of OCs was also associated with referral for TMD care, with an increased risk of TMD of approximately 20% for OC users, after controlling for health services use (P<0.05). These results suggest that female reproductive hormones may play an etiologic role in orofacial pain. This relationship warrants further investigation through epidemiologic, clinical and basic research.

Risk Factors for Diagnostic Subgroups of Painful Temporomandibular Disorders (TMD)

Temporomandibular Disorders (TMD) encompass several entities, which may have differing etiologies. To test this hypothesis, we investigated risk factors for three diagnostic subgroups of painful TMD. Ninety-seven subjects with myofascial pain only, 20 with arthralgia only, 157 with both myofascial pain and arthralgia, and 195 controls without TMD pain met criteria for study eligibility. Investigated risk factors included both physical and psychological variables. Adjusted odds ratios were calculated by multiple logistic regression analyses. Myofascial pain occurring alone was significantly associated with trauma (Odds Ratio {OR} = 2.0), clenching (OR = 4.8), third molar removal (OR = 3.2), somatization (OR = 3.7), and female gender (OR = 4.2). Myofascial pain with arthralgia was significantly associated with trauma (OR = 2.1), clenching (OR = 3.3), third molar removal (OR = 4.0), somatization (OR = 5.1), and female gender (OR = 4.7). No significant associations were found for the small-arthralgia-only group.

Assessing clinical signs of temporomandibular disorders: Reliability of clinical examiners

Data on interrater reliability in assessing a number of clinical signs commonly evaluated in the diagnosis and treatment of temporomandibular disorders (TMD) is presented in this article. Four experienced dental hygienists who were field examiners for a large epidemiologic study of TMD and three experienced clinical TMD specialists (dentists) who are coinvestigators in the same study followed carefully detailed specifications and criteria for examination of TMD patients and pain-free controls. Excellent reliability was found for vertical range of motion measures and for summary indices measuring the overall presence of a clinical sign that could arise from several sources (for example, summary indices of muscle palpation pain). However, many clinical signs important in the differential diagnosis of subtypes of TMD were not measured with high reliability. In particular, assessment of pain in response to muscle palpation and identification of specific temporomandibular joint sounds seemed to be possible only with modest, sometimes marginal, reliability. These modest reliabilities could arise from examiner error because the clinical signs are themselves unreliable, changing spontaneously over time and making it difficult to find the same sign on successive examinations. The finding that, without calibration, experienced clinicians showed low reliability with other clinicians suggests the importance of establishing reliable clinical standards for the examination and diagnostic classification of TMD.

Relationship of pain and symptoms to pubertal development in adolescents

&NA; Temporomandibular disorder (TMD) pain, abdominal pain, migraine and tension‐type headache are more prevalent in women than in men. This study assessed the relationship of back pain, headache, abdominal pain, TMD pain, and the presence of multiple pain conditions to gender and pubertal development in a cross‐sectional, population‐based survey of adolescents. We also examined the association between pubertal development and depressive and somatic symptoms, factors often associated with pain in adults. We hypothesized that prevalence of all pain conditions, as well as rates of other symptoms, would increase as puberty progresses in females, but not males. Subjects (3101 boys and girls, 11–17 years old, selected from an HMO population) reported on the presence of each pain condition in the prior 3 months and completed scales assessing pubertal development, and depressive and somatic symptoms. Data were analyzed using descriptive statistics and multivariate logistic regression. Prevalence rates were weighted for factors affecting response. Prevalence of back pain, headache and TMD pain increased significantly (odds ratios, OR=1.4–2.0, P<0.001) and stomach pain increased marginally with increasing pubertal development in girls. Rates of somatization, depression and probability of experiencing multiple pains also increased with pubertal development in girls (P<0.0001). For boys, prevalence of back (OR=1.9, P<0.0001) and facial pain (OR=1.5, P<0.01) increased, stomach pain decreased somewhat and headache prevalence was virtually unchanged with increasing maturity. For both sexes, pubertal development was a better predictor of pain than was age. Thus it appears that pain, other somatic symptoms and depression increase systematically with pubertal development in girls.

Gender differences in pain modulation by diffuse noxious inhibitory controls: a systematic review.

&NA; Over the last decade, extensive research has demonstrated sex differences in pain perception and modulation. Several factors have been proposed to account for the differences observed between men and women, including pain modulation through diffuse noxious inhibitory controls (DNIC). Studies investigating sex differences in DNIC have shown mixed results, with some reporting decreased DNIC effect in women compared with men, while others found no difference in DNIC between the sexes. Additional studies have investigated DNIC in both sexes without focusing on sex differences. This systematic review aimed to answer the following question: “In humans of reproductive age without chronic pain, are women more likely than men to have decreased Diffuse Noxious Inhibitory Controls?” Relevant studies were identified by computerized searches of Pubmed/Medline, Embase, Biosis, Web of Science, PsycInfo and Cochrane (from January 1980 through February 2009). The search was limited to human studies with no language restriction. The initial search identified 718 titles and abstracts. Seventeen studies were included in the final stage and data regarding age and gender of participants, methodology and outcome measurements were extracted and analyzed. The majority of studies using pain report as the outcome found significantly more efficient DNIC in males than females (mean female/male ratio = 0.54). Studies evaluating pain thresholds and nociceptive flexion reflex indicated the opposite when simply averaged across studies; however, weighted analyses of threshold found more efficient DNIC in males. Gender differences in DNIC effect depend on both the experimental methodology and the modes of measurement of the effect.

Widespread pain as a risk factor for dysfunctional temporomandibular disorder pain

&NA; Widespread pain has been found to be a risk factor for onset and persistence of temporomandibular disorder (TMD) pain. The aim of this cohort study was to determine if widespread pain is associated with interference and disability related to TMD pain. Three hundred and ninety‐seven TMD patients were interviewed at 1 and 2 years following enrollment. Dysfunctional TMD pain was defined as grades IV, III and II with any disability points on the graded chronic pain scale (GCPS). Widespread pain was defined by the number of pain sites (0–4: head, back, stomach, chest) outside the masticatory system. Multivariable logistic regression analysis, controlling for the effects of age, education, depression, baseline GCPS, and time since study enrollment, was used to examine the relationship between widespread pain and risk of onset or maintenance of dysfunctional TMD pain during follow‐up. Among women without dysfunctional TMD pain at baseline, widespread pain was a risk factor for development of dysfunctional TMD pain (odds ratio (OR): 1.9, 95% confidence interval (CI): 1.2–2.8, P=0.003). However, there was no association between widespread pain and onset of dysfunctional TMD pain among men (OR: 1.0, 95% CI: 0.4–2.8, P=0.95) or maintenance of dysfunctional TMD among either women (OR: 1.0, 95% CI: 0.8–1.4, P=0.85) or men (OR: 0.4, 95% CI: 0.1–3.2, P=0.40). Widespread pain was independently and highly associated with risk of developing pain‐related disability among women who did not have pain dysfunction at baseline, but was not predictive of risk of onset of dysfunctional TMD pain among men or maintenance of dysfunctional pain among either women or men.

Dimensions of Oral-health-related Quality of Life

Oral-health-related quality of life (OHRQoL) is expected to have multiple dimensions. It was the aim of this study to investigate the dimensional structure of OHRQoL measured by the Oral Health Impact Profile (German version) (OHIP-G) and to derive a summary score for the instrument. Subjects (N = 2050; age, 16–79 yrs) came from a national survey. We used rotated principal-components analysis to derive a summary score and to explore the dimensional structure of OHIP-G. The first principal component explained 50% of the variance in the data. The sum of OHIP-G item responses was highly associated with the first principal component (r = 0.99). This simple but informative OHIP-G summary score may indicate that simple sums are also potentially useful scores for other OHRQoL instruments. Four dimensions (psychosocial impact, orofacial pain, oral functions, appearance) were found. These OHIP-G dimensions may serve as a parsimonious set of OHRQoL dimensions in general.

Predictors of onset of facial pain and temporomandibular disorders in early adolescence.

Abstract There are few prospective studies assessing risk factors for onset of temporomandibular (TMD) pain disorders in any age group. The aim of this prospective cohort study was to identify risk factors for onset of clinically significant TMD pain (i.e., pain meeting research diagnostic criteria for myofascial pain and/or arthralgia) during early adolescence. Subjects were 1,996 boys and girls, initially 11 years old, randomly selected from a large nonprofit health care system. Subjects completed a baseline telephone interview and were followed up with mailed questionnaires every 3 months for 3 years. At baseline and all follow ups, subjects were asked to report the presence of facial pain in the past 3 months. Subjects reporting a first onset of facial pain received a standardized clinical examination. In multivariate analyses, baseline predictors of clinically significant pain included female gender [Odds Ratio (OR) = 2.0, 95% Confidence Interval (CI) = 1.2–3.3] and negative somatic and psychological symptoms including somatization (OR = 1.8, CI = 1.1–2.8), number of other pain complaints (OR = 3.2, CI = 1.7–6.1) and life dissatisfaction (OR = 4.1, CI = 1.9–9.0). Many of the risk factors for onset of clinically significant TMD pain in adolescents are similar to risk factors for onset of TMD and other pain problems in adults, as well as risk factors for onset of other pain conditions in adolescents. These findings suggest that the development of TMD pain in adolescence may reflect an underlying vulnerability to musculoskeletal pain that is not unique to the orofacial region.

Age and Gender Trends in Long-Term Opioid Analgesic Use for Noncancer Pain

OBJECTIVES We describe age and gender trends in long-term use of prescribed opioids for chronic noncancer pain in 2 large health plans. METHODS Age- and gender-standardized incident (beginning in each year) and prevalent (ongoing) opioid use episodes were estimated with automated health care data from 1997 to 2005. Profiles of opioid use in 2005 by age and gender were also compared. RESULTS From 1997 to 2005, age-gender groups exhibited a total percentage increase ranging from 16% to 87% for incident long-term opioid use and from 61% to 135% for prevalent long-term opioid use. Women had higher opioid use than did men. Older women had the highest prevalence of long-term opioid use (8%-9% in 2005). Concurrent use of sedative-hypnotic drugs and opioids was common, particularly among women. CONCLUSIONS Risks and benefits of long-term opioid use are poorly understood, particularly among older adults. Increased surveillance of the safety of long-term opioid use is needed in community practice settings.