Facial pain and temporomandibular disorders: an epidemiological study of the Northern Finland 1966 Birth Cohort

Effects of autogenic and reciprocal inhibition muscle energy techniques on isometric muscle strength in neck pain: A randomized controlled trial

BACKGROUND

Neck is one of the most common sites of musculoskeletal symptoms, and muscle shortening and weakness is observed to be a common cause of neck pain and disability.

OBJECTIVE

To compare the immediate and short term effects of static stretching (SS), autogenic inhibition (AI) and reciprocal inhibition (RI) muscle energy techniques (MET) on isometric muscle strength in the management of mechanical neck pain.

METHODS

A randomized controlled trial was conducted on 78 participants with neck pain randomly allocated to SS, AI-MET and RI-MET groups. All the participants received Trans Cutaneous Electrical Nerve Stimulation (TENS), hot pack and unilateral postero-anterior glide, followed by 3-5 repetitions of either SS, AI-MET or RI-MET for five consecutive sessions. Numeric pain rating scale (NPRS) and Modified Sphygmomanometer Dynamometry (MSD) were used as outcome measurement tools. One way ANOVA and repeated measures ANOVA were used for inter-group and intra-group comparison.

RESULT

In terms of MSD scores, a significant difference (p< 0.05) was observed between the groups. Both AI-MET and RI-MET were found to be comparatively more effective than SS, however AI-MET was found to be the most effective.

CONCLUSION

AI-MET is more effective than SS and RI-MET in terms of improving isometric muscle strength in patients with mechanical neck pain.

Ten-year Longitudinal Follow-up MRI Study of Age-related Changes in Thoracic Intervertebral Discs in Asymptomatic Subjects

STUDY DESIGN

Prospective longitudinal study.

OBJECTIVE

The aim of this study was to evaluate long-term degenerative changes in intervertebral discs in the thoracic spine in healthy asymptomatic subjects.

SUMMARY OF BACKGROUND DATA

Longitudinal magnetic resonance imaging (MRI) studies of intervertebral disc degeneration have been reported for the cervical and lumbar but not the thoracic spine.

METHODS

In this longitudinal study (average follow-up 10.0 ± 0.6 years), we assessed degenerative changes in the thoracic spine of 103 volunteers (58 men) of 223 healthy volunteers in the initial MRI study of the thoracic spine (follow-up rate 46.2%). The mean age at the initial study was 45.0 ± 11.5 years (24-77 years). Initial and follow-up thoracic-spine MRIs were graded for the following 4 factors of degenerative changes: decrease in signal intensity of intervertebral disc (DSI), posterior disc protrusion (PDP), anterior compression of dura and spinal cord (AC), and disc-space narrowing (DSN) from T1-2 to T12-L1. We assessed associations between changes in MRI grade and demographical factors such as age, sex, body mass index, smoking habits, sports activities, and disc degeneration in the cervical spine.

RESULTS

MRIs revealed that 63.1% of the subjects had degenerative changes in the thoracic intervertebral discs that had progressed at least one grade during the follow-up period. DSI progressed in 44.7% of subjects, PDP in 21.4%, and AC in 18.4% during the 10-year period. No DSN progression was seen. DSI was frequently observed in the upper thoracic spine (T1-2 to T4-5). Disc degeneration was relatively scarce in the lower thoracic spine (T9-10 to T12-L1). PDP was frequently observed in the middle thoracic spine (T5-6 toT8-9). We found significant associations between DSI and cervical-spine degeneration (P = .004) and between AC and smoking (P = .04).

CONCLUSION

Progressive thoracic disc degeneration, observed in 63.1% of subjects; was significantly associated with smoking and with cervical-spine degeneration.

LEVEL OF EVIDENCE

2.

Self-Reported Pain in Male and Female Iraq/Afghanistan-Era Veterans: Associations with Psychiatric Symptoms and Functioning

Objective

To examine pain symptoms and co-occurring psychiatric and functional indices in male and female Iraq/Afghanistan-era veterans.

Design

Self-reported data collection and interviews of Iraq/Afghanistan-era veterans who participated in a multisite study of postdeployment mental health.

Setting

Veterans were enrolled at one of four participating VA sites.

Subjects

Two thousand five hundred eighty-seven male and 662 female Iraq/Afghanistan-era veterans.

Methods

Nonparametric Wilcoxon rank tests examined differences in pain scores between male and female veterans. Chi-square tests assessed differences between male and female veterans in the proportion of respondents endorsing moderate to high levels of pain vs no pain. Multilevel regression analyses evaluated the effect of pain on a variety of psychiatric and functional measures.

Results

Compared with males, female veterans reported significantly higher mean levels of headache ( P  < 0.0001), muscle soreness ( P  < 0.008), and total pain ( P  < 0.0001), and were more likely to report the highest levels of headache ( P  < 0.0001) and muscle soreness ( P  < 0.0039). The presence of pain symptoms in Iraq/Afghanistan-era veterans was positively associated with psychiatric comorbidity and negatively associated with psychosocial functioning. There were no observed gender differences in psychiatric and functional indices when levels of pain were equated.

Conclusions

Although female Iraq/Afghanistan-era veterans reported higher levels of pain than male veterans overall, male and female veterans experienced similar levels of psychiatric and functional problems at equivalent levels of reported pain. These findings suggest that pain-associated psychological and functional impacts are comparable and consequential for both male and female veterans.

An exploratory pilot investigation of neurosteroids and self-reported pain in female Iraq/Afghanistan-era Veterans

Female Veterans are the most rapidly growing segment of new users of the Veterans Health Administration (VHA), and a significant proportion of female Veterans receiving treatment from VHA primary care providers report persistent pain symptoms. Currently, available data characterizing the neurobiological underpinnings of pain disorders are limited. Preclinical data suggest that neurosteroids may be involved in the modulation of pain symptoms, potentially via actions at gamma-aminobutyric acid (GABA) and N-methyl-D-aspartate (NMDA) receptors. Dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEAS) are neurosteroids that modulate inhibitory GABA receptors and excitatory NMDA receptors, producing complex neuronal effects. Emerging evidence from male Iraq/Afghanistan-era Veterans suggests that reductions in neurosteroid levels are associated with increased pain symptoms and that neurosteroids may be promising biomarker candidates. The current exploratory study thus examined associations between self-reported pain symptoms in 403 female Iraq/Afghanistan-era Veterans and serum DHEAS and DHEA levels. Serum DHEAS levels were inversely correlated with low back pain in female Veterans (Spearman r = -0.103; p = 0.04). Nonparametric analyses indicate that female Veterans reporting moderate/extreme low back pain demonstrated significantly lower DHEAS levels than those reporting no/little low back pain (|Z| = 2.60; p = 0.009). These preliminary findings support a role for DHEAS in pain physiology of low back pain and the rationale for neurosteroid therapeutics in pain analgesia.

Assessing the prevalence of autoimmune, endocrine, gynecologic, and psychiatric comorbidities in an ethnically diverse cohort of female fibromyalgia patients: does the time from hysterectomy provide a clue?

Background

This retrospective chart review investigated differences in the prevalence of medical comorbidity between women with fibromyalgia (FM) (n=219) and a control group women with chronic pain (CP) without FM (n=116). The specific aims were to compare the prevalence of autoimmune, psychiatric, endocrine, gynecologic pathology, the relationship between timing of gynecologic surgery, and pain onset. We additionally sought to compare the number of comorbidities in an ethnically diverse cohort.

Methods

This was a retrospective chart review of patients seen in FM or CP clinics at an academic medical center in 2009–2010.

Results

Logistic regression modeling found that gynecologic, endocrine, and autoimmune diagnoses were independently associated with a diagnosis of FM. Detailed analyses showed that thyroid disease (P<0.01) and gynecologic surgery (P<0.05) were significantly more common in FM. Women with FM were more likely to have multiple autoimmune, endocrine, gynecologic, or psychiatric pathologies. A relationship was observed between the timing of gynecologic surgery and pain onset in FM, with more surgeries observed in the years just prior to pain onset or in the year after pain onset. A similar pattern was not found in the control group.

Conclusion

This study demonstrates that autoimmune, endocrine, and gynecologic pathologies occur more commonly in women with FM than in those with CP, which is consistent with findings in less ethnically diverse samples. Moreover, a relationship was found between timing of pain onset and gynecologic surgery. A larger prospective study of the relationship between gynecologic surgery and pain onset in FM is warranted.

Do changes in oral health-related quality-of-life, facial pain and temporomandibular disorders correlate after treatment of severe malocclusion?

INTRODUCTION

The aim was to evaluate the relationships of changes in facial pain, temporomandibular disorders (TMDs) and oral health-related quality-of-life (OHRQoL) in adults who underwent orthodontic or orthodontic/surgical treatment.

METHODS

Sixty-four patients (46 women, 18 men, range 18-64 years) with severe malocclusion and functional problems were treated in Oulu University Hospital. Of these, 44 underwent orthodontic-surgical and 20 orthodontic treatment. Data were collected with questionnaires and clinical stomatognathic examinations before and on average 3 years after treatment. The OHRQoL was measured with OHIP-14 (The Oral Health Impact Profile), the intensity of facial pain with the Visual Analogue Scale (VAS) and the severity of TMD with the Helkimo's anamnestic (Ai) and clinical (Di) dysfunction indices.

RESULTS

A significant improvement was found in facial pain, signs and symptoms of TMD and OHRQoL after the treatment (p < 0.05). The decrease in VAS was associated with improvement in OHIP-14 severity (r = 0.296, p = 0.019). The correlations between changes in OHIP-14 severity and Ai and Di were not statistically significant.

CONCLUSION

Treatment of severe malocclusion seemed to improve OHRQoL via decreased facial pain. Decreased facial pain was associated especially with improved OHRQoL dimensions of physical pain, physical disability and social disability.

Trigeminal Inflammatory Compression (TIC) injury induces chronic facial pain and susceptibility to anxiety-related behaviors

Our laboratory previously developed a novel neuropathic and inflammatory facial pain model for mice referred to as the Trigeminal Inflammatory Compression (TIC) model. Rather than inducing whole nerve ischemia and neuronal loss, this injury induces only slight peripheral nerve demyelination triggering long-term mechanical allodynia and cold hypersensitivity on the ipsilateral whisker pad. The aim of the present study is to further characterize the phenotype of the TIC injury model using specific behavioral assays (i.e. light-dark box, open field exploratory activity, and elevated plus maze) to explore pain- and anxiety-like behaviors associated with this model. Our findings determined that the TIC injury produces hypersensitivity 100% of the time after surgery that persists at least 21 weeks post injury (until the animals are euthanized). Three receptive field sensitivity pattern variations in mice with TIC injury are specified. Animals with TIC injury begin displaying anxiety-like behavior in the light-dark box preference and open field exploratory tests at week eight post injury as compared to sham and naïve animals. Panic anxiety-like behavior was shown in the elevated plus maze in mice with TIC injury if the test was preceded with acoustic startle. Thus, in addition to mechanical and cold hypersensitivity, the present study identified significant anxiety-like behaviors in mice with TIC injury resembling the clinical symptomatology and psychosocial impairments of patients with chronic facial pain. Overall, the TIC injury model's chronicity, reproducibility, and reliability in producing pain- and anxiety-like behaviors demonstrate its usefulness as a chronic neuropathic facial pain model.

Quality of life and neck pain in nurses

OBJECTIVES

To investigate the association between neck pain and psychological stress in nurses.

MATERIAL AND METHODS

Nurses from the Avon Orthopaedic Centre completed 2 questionnaires: the Short Form-36 (SF-36) and 1 exploring neck pain and associated psychological stress.

RESULTS

Thirty four nurses entered the study (68% response). Twelve (35.3%) had current neck pain, 13 (38.2%) reported neck pain within the past year and 9 (26.5%) had no neck pain. Subjects with current neck pain had significantly lower mental health (47.1 vs. 70.4; p = 0.002), physical health (60.8 vs. 76.8; p = 0.010) and overall SF-36 scores (56.8 vs. 74.9; p = 0.003). Five (41.7%) subjects with current neck pain and 5 (38.5%) subjects with neck pain in the previous year attributed it to psychological stress.

CONCLUSIONS

Over 1/3 of nurses have symptomatic neck pain and significantly lower mental and physical health scores. Managing psychological stress may reduce neck pain, leading to improved quality of life for nurses, financial benefits for the NHS, and improved patient care.

Psychosocial behaviour and health care utilization in patients suffering from temporomandibular disorders diagnosed on the basis of clinical findings and MRI examination

The aim of this study was to evaluate psychosocial behaviour and differences in health care utilization between subgroups of patients suffering from temporomandibular disorders, using both clinical examination and magnetic resonance imaging (MRI).

MATERIALS AND METHODS

70 patients were examined according to the research diagnostic criteria for temporomandibular disorders (RDC/TMD), and were divided into groups according to their clinical diagnoses. MRIs were acquired and joint-related RDC/TMD diagnoses were modified on the basis of MRI findings. Group I suffered from joint pathology, group II from myofascial pain and group III from a combination. Non-parametric statistics were used to reveal group-related differences in psychosocial and behavioural aspects. Differences in group assignment based on clinical and MRI examination were assessed (kappa statistics).

RESULTS

MRI findings led to group assignments that were different from clinical assignments (k = 0.3). For both types of assignment, patients with myofascial pain displayed higher somatization scores, used more splints and consulted more physicians. For clinical assignment only, depression scores were higher in the myofascial pain group. For MRI based assignment, sex differences were significant between groups I and III.

CONCLUSION

Somatization-specific behaviour is more widespread in patients suffering from exclusively myofascial pain than in patients presenting joint pathology. Inconsistencies in differences of other psychosocial variables between groups of TMD patients seem to be related to differences in group assignment either with or without objective information on joint pathology.

Magnetic resonance characteristics of temporomandibular joint disc displacement in elderly patients

OBJECTIVES

The purpose of this study was to evaluate the MR characteristics of temporomandibular joint (TMJ) disc displacement in elderly patients.

METHODS

Of the MR images of 1660 TMJs in 847 patients with disc displacement who underwent MRI for suspected temporomandibular disorders, 301 TMJs in 154 patients aged over 50 years were studied as an elderly group. These MR images of the elderly group were compared with those of a control group (1359 TMJs in 693 patients aged under 51 years) concerning disc displacement with or without reduction, joint effusion and osteoarthrosis.

RESULTS

The incidence of disc displacement with osteoarthrosis was significantly different between the elderly (41.9%) and the control (19.8%) groups (p = 0.000). Logistic multivariate regression analysis demonstrated that the osteoarthrosis was a significant variable (odds ratio = 2.94, p = 0.000).

CONCLUSIONS

This study suggests that MR characteristics of TMJ disc displacement in elderly patients includes osteoarthrosis.

Neurobiology of estrogen status in deep craniofacial pain

Pain in the temporomandibular joint (TMJ) region often occurs with no overt signs of injury or inflammation. Although the etiology of TMJ-related pain may involve multiple factors, one likely risk factor is female gender or estrogen status. Evidence is reviewed from human and animal studies, supporting the proposition that estrogen status acts peripherally or centrally to influence TMJ nociceptive processing. A new model termed the "TMJ pain matrix" is proposed as critical for the initial integration of TMJ-related sensory signals in the lower brainstem that is both modified by estrogen status, and closely linked to endogenous pain and autonomic control pathways.

Neck pain in Hong Kong: a telephone survey on consequences and health service utilization

STUDY DESIGN

A regionally representative telephone survey using a 2-stage randomization process.

OBJECTIVE

(1) To investigate the prevalence and consequence of neck pain in terms of disability and rate of absenteeism from work. (2) To describe the health services utilization pattern of neck pain subjects and to analyse the factors associated with neck pain and health services utilization pattern.

SUMMARY OF BACKGROUND DATA

There has been a lack of reliable information on the health service utilization pattern of neck pain subjects, the consequences and the patient perceived effectiveness of neck pain management in Hong Kong and Asian countries.

METHODS

Subjects were interviewed on the sociodemographic characteristics, occurrence and consequences of neck pain, and the health utilization pattern. A random sample of the respondents was re-interviewed 7 to 10 days after the initial interview, by an independent interviewer for the reliability check.

RESULTS

A total of 4640 subjects were interviewed. The 12-month prevalence was 64.6% (95% CI: 63.2%-66.0%). About 38.0% of these patients suffered from moderate to severe pain. Moreover, 17.7% of these subjects had to limit their social activities and 19% had to limit their work. About 25% of those subjects had consulted medical or health practitioners. Medical consultation is the majority and physiotherapy came second. Self-massage was the most preferred (83.3%) mode of self-care. Physiotherapy was regarded as the most effective health service, with 60% of the respondents' neck pain completely removed. Although most people chose self-massage to be the most effective self-care treatment, only one-third (30.2%) of them had their neck pain improved by less than a half.

CONCLUSION

Neck pain is highly prevalent with an increasing impact in Hong Kong. More than one-third of neck pain patients suffered from moderate to severe pain and around 20% of them had to limit their work. About 25% of neck pain patient have consulted medical or health professionals. Physiotherapy and private medical clinic were the 2 service providers with high percentage of perceived complete improvement. There was a general trend that more neck pain patients used complementary therapies.

Pain among Veterans of Operations Enduring Freedom and Iraqi Freedom: do women and men differ?

OBJECTIVE

To evaluate sex differences in the prevalence of overall pain, moderate-severe pain, and persistent pain among Veterans of Operations Enduring Freedom and Iraqi Freedom seen at VA outpatient clinics, and to evaluate sex differences in pain assessment.

DESIGN

The observational cohort consisted of Veterans discharged from the U.S. military from October 1, 2001 to November 30, 2007 that enrolled for Veterans Administration (VA) services or received VA care before January 1, 2008. We limited the sample to the 153,212 Veterans (18,481 female, 134,731 male) who had 1 year of observation after their last deployment.

RESULTS

Pain was assessed in 59.7% (n = 91,414) of Veterans in this sample. Among those assessed, 43.3% (n = 39,591) reported any pain, 63.2% (n = 25,028) of whom reported moderate-severe pain. Over 20% (n = 3,427) of Veterans with repeated pain measures reported persistent pain. We found no significant difference in the probability of pain assessment by sex (RR = 0.98, 95% CI 0.96, 1.00). Female Veterans were less likely to report any pain (RR 0.89, 95% CI 0.86, 0.92). Among those with any pain, female Veterans were more likely to report moderate-severe pain (RR 1.05, 95% CI 1.01, 1.09) and less likely to report persistent pain (RR 0.90, 95% CI 0.81, 0.99).

CONCLUSIONS

As the VA plans care for the increasing numbers of female Veterans returning from Iraq and Afghanistan, a better understanding of the prevalence of pain, as well as sex-specific variations in the experience and treatment of pain, is important for policy makers and providers who seek to improve identification and management of diverse pain disorders.

Sex, gender, and pain: a review of recent clinical and experimental findings

Sex-related influences on pain and analgesia have become a topic of tremendous scientific and clinical interest, especially in the last 10 to 15 years. Members of our research group published reviews of this literature more than a decade ago, and the intervening time period has witnessed robust growth in research regarding sex, gender, and pain. Therefore, it seems timely to revisit this literature. Abundant evidence from recent epidemiologic studies clearly demonstrates that women are at substantially greater risk for many clinical pain conditions, and there is some suggestion that postoperative and procedural pain may be more severe among women than men. Consistent with our previous reviews, current human findings regarding sex differences in experimental pain indicate greater pain sensitivity among females compared with males for most pain modalities, including more recently implemented clinically relevant pain models such as temporal summation of pain and intramuscular injection of algesic substances. The evidence regarding sex differences in laboratory measures of endogenous pain modulation is mixed, as are findings from studies using functional brain imaging to ascertain sex differences in pain-related cerebral activation. Also inconsistent are findings regarding sex differences in responses to pharmacologic and non-pharmacologic pain treatments. The article concludes with a discussion of potential biopsychosocial mechanisms that may underlie sex differences in pain, and considerations for future research are discussed.

PERSPECTIVE

This article reviews the recent literature regarding sex, gender, and pain. The growing body of evidence that has accumulated in the past 10 to 15 years continues to indicate substantial sex differences in clinical and experimental pain responses, and some evidence suggests that pain treatment responses may differ for women versus men.

Evaluation of disk position and prevalence of internal derangement, in a sample of the elderly, by gadolinium-enhanced magnetic resonance imaging

OBJECTIVES

To assess disk position and the prevalence of disk displacement (DD) in a sample of the elderly by use of contrast agent-enhanced magnetic resonance imaging (MRI).

STUDY DESIGN

Thirty subjects (73-75 years old) were drawn from a representative sample and examined clinically. The position and contours of the temporomandibular disk was assessed by using gadolinium-enhanced MR images which were evaluated by 2 independent raters. Statistical assessment was performed by using descriptive statistics and nonparametric tests.

RESULTS

Agreement between raters with respect to disk position was excellent. The MRI showed that 8 subjects (27%; 2 men, 6 women) had DD.

CONCLUSION

Gadolinum-enhanced MRI showed that DD is common in the elderly (27%) and that DD occurs more frequently in women than in men. In women without DD the disk is positioned more anteriorly than in men.

The Prevalence and Age-Related Characteristics of Pain in a Sample of Women Veterans Receiving Primary Care

BACKGROUND

Women veterans are a growing but understudied population believed to be at increased risk for pain problems. Because of risk factors and clinical observations, we hypothesized that women veterans might have a high prevalence of pain and, thus, sought to determine the prevalence of (and age-related variations in) pain and to characterize several key pain dimensions in a sample of women veterans.

METHODS

Women with routine appointments at the VA Connecticut Women's Health Center were recruited for study. Participants completed a 59-item questionnaire that provided information about their demographic, clinical, and pain status, as well as use of health services.

RESULTS

Of 236 women approached, 213 (89%) completed the questionnaire. The mean age was 52 years, and most (78%) reported an ongoing pain problem. For those reporting pain, the mean duration of pain was 6 years, average pain intensity was 6.3 (range 1-10), and commonly endorsed pain sites included lower extremity (68%), low back (63%), and shoulder (48%). The most frequently endorsed treatment (by 80%) was analgesic medication use. Across the four age categories (20-35, 36-50, 51-65, and > or =66 years), pain prevalences were 64%, 89%, 83%, and 69%, respectively. Although pain intensity levels did not vary across age groups, older women (> or =66) reported using fewer pain treatments, including analgesic medications. Finally, those with (vs. those without) pain reported a greater number of medical and mental health visits in the preceding year.

CONCLUSIONS

This study documented a significantly high prevalence of pain among a sample of women veterans receiving primary care in a VA women's health clinic.

The prevalence of signs and symptoms of temporomandibular disorders in very old subjects

Previous studies on the prevalence of signs of temporomandibular disorders (TMD) in elderly people have used non-standardized and invalidated examination protocols. The prevalence of the different signs of TMD in this group is therefore still unclear. The aim of this study was to evaluate the prevalence of signs of TMD in subjects of advanced aged, using a standardized and validated examination protocol. Additionally, young subjects were examined as a control group. Fifty-eight old peoples' home inhabitants and 44 young subjects were examined using a standardized and validated examination protocol. Differences between the groups were assessed using Mann-Whitney U-test or t-test. Geriatric subjects more often exhibited objective symptoms of TMD (38% exhibited joint sounds on opening), but rarely suffered from pain (pain at rest: 0%, joint pain: 0%, muscle pain: 12%). In contrast, young subjects rarely exhibited objective symptoms (joint sounds: 7%), but suffered more frequently from pain (facial: 7%, joint pain: 16%, muscle pain: 25%). The mandibular range of motion was higher in young subjects. Differences between the groups with respect to joint sounds, muscular palpation pain and mandibular range of motion were significant. Although older subjects more frequently exhibited objective signs (joint sounds) of TMD, they rarely suffered from pain. In contrast, younger subjects rarely exhibited objective TMD signs but more frequently suffered from subjective signs (muscular pain on palpation) and facial pain.

The prevalence of neck pain in the world population: a systematic critical review of the literature

The objective of this study was to determine the prevalence of neck pain (NP) in the world population and to identify areas of methodological variation between studies. A systematic search was conducted in five databases (MEDLINE, EMBASE, CINAHL, OSH-ROM, and PsycINFO), followed by a screening of reference lists of relevant papers. Included papers were extracted for information and each paper was given a quality score. Mean prevalence estimates were calculated for six prevalence periods (point, week, month, 6 months, year, and lifetime), and considered separately for age, gender, quality score, response rate, sample size, anatomical definition, geography, and publication year. Fifty-six papers were included. The six most commonly reported types of prevalence were point, week, month, 6 months, year, and lifetime. Except for lifetime prevalence, women reported more NP than men. For 1-year prevalence, Scandinavian countries reported more NP than the rest of Europe and Asia. Prevalence estimates were not affected by age, quality score, sample size, response rate, and different anatomical definitions of NP. NP is a common symptom in the population. As expected, the prevalence increases with longer prevalence periods and generally women have more NP than men. At least for 1-year prevalence Scandinavian countries report higher mean estimates than the rest of Europe and Asia. The quality of studies varies greatly but is not correlated with the prevalence estimates. Design varies considerably and standardisation is needed in future studies.

[The temporo-mandibular articulation]

The standing posture of humans has created both morphological and functional adaptations in the temporo-mandibular joint and the masticatory function. This biped state is the one of the most important characteristic of human evolution. It is furthermore the agent determining most of the functional changes in the whole body. This survey will be carried out in several levels including, a descriptive anatomy, biomechanics, radiological imaging, functioning in the articulation of TMJ. The descriptive anatomic picture will be obtained by the traditional dissection techniques. 20 TMJ joints are dissected from 10 cadavers: 7 cadavers, 65-75 year old, 3 cadavers, 60-65 year old. The x-rays are lateral view and the subjects of the radiological imaging are young's, adults and olds: 1, 3 y-old Male; 1, 7 y-old Female; 1, 14 y-old Female; 10, 19-23 y-old Male; 1, 26 y-old Female; 1, 34 y-old Male; 1, 75 y-old Female. The anatomic elements in the TMJ well resembled the ones described in the literature of the capsule, the ligament, the masticator muscles (masseter, temporal, medial and lateral pterygoids). The temporo-mandibular ligament proved to be difficult to separate from the capsule in some of the specimens. Sometimes it was not always found after a dissection.

A systematic review of low level laser therapy with location-specific doses for pain from chronic joint disorders

We investigated if low level laser therapy (LLLT) of the joint capsule can reduce pain in chronic joint disorders. A literature search identified 88 randomised controlled trials, of which 20 trials included patients with chronic joint disorders. Six trials were excluded for not irradiating the joint capsule. Three trials used doses lower than a dose range nominated a priori for reducing inflammation in the joint capsule. These trials found no significant difference between active and placebo treatments. The remaining 11 trials including 565 patients were of acceptable methodological quality with an average PEDro score of 6.9 (range 5-9). In these trials, LLLT within the suggested dose range was administered to the knee, temporomandibular or zygapophyseal joints. The results showed a mean weighted difference in change of pain on VAS of 29.8 mm (95% CI, 18.9 to 40.7) in favour of the active LLLT groups. Global health status improved for more patients in the active LLLT groups ( relative risk of 0.52; 95% CI 0.36 to 0.76). Low level laser therapy with the suggested dose range significantly reduces pain and improves health status in chronic joint disorders, but the heterogeneity in patient samples, treatment procedures and trial design calls for cautious interpretation of the results.

The value of maximum jaw motion measurements for distinguishing between common temporomandibular disorder subgroups

OBJECTIVE

The purpose of this study was to determine if mandibular motion measurements could be used to distinguish between common temporomandibular disorder (TMD) subgroups that were established on the basis of only clinical signs and symptoms.

STUDY DESIGN

Patients were 41 consecutive TMD clinic patients (31 women and 10 men). These patients were divided into 6 typical TMD subgroups. The subgroups were patients with (1) arthromyalgia, (2) arthromyalgia with disk condyle incoordination, (3) disk condyle incoordination only, (4) osteoarthritis, (5) suspected disk displacement without reduction, or (6) other diagnoses.

RESULTS

There were no subjects in the other-diagnosis subgroup and only 1 subject with suspected disk displacement without reduction who was dropped without further consideration. The data for mean age showed that the osteoarthritis subgroup (n = 12) was statistically older (17 years) than the disk-condyle-incoordination-only subgroup (n = 11). The mean age of the other 2 groups, arthromyalgia (n = 11) and arthromyalgia with disk condyle incoordination (n = 6), was between the osteoarthritis and the disk-condyle-incoordination-only subgroups. For the 4 TMD subgroups whose data were analyzed, the mean differences between similar jaw opening measurements ranged from 6 to 8 mm with a standard deviation of approximately 8 to 10 mm. The mean left lateral motions were 0.5 to 1.3 mm larger than observed on the right. The widest mean jaw opening (56 mm) occurred in the disk-condyle-incoordination-only group. These differences were not found to be statistically significant.

CONCLUSION

Analysis of opening, lateral and protrusive jaw motion data showed these measurements could not reliably differentiate between patients with osteoarthritis, arthromyalgia, arthromyalgia with disk condyle incoordination and disk condyle incoordination only.