Correlation between pressure pain threshold and pain intensity in patients with temporomandibular disorders who are compliant or non-compliant with conservative treatment

Association of night-time sleep and daytime napping with painful temporomandibular disorder

BACKGROUND

Painful temporomandibular disorder (TMD) is the common cause of chronic oro-facial pain, which may interfere with sleep. Previous studies have documented an association between sleep and TMD.

OBJECTIVES

This study aimed to further explore the association of night-time sleep and daytime napping with painful TMD.

METHODS

A total of 419 patients (aged 31.88 ± 11.54 years with women forming 85.4%) from a TMD/Orofacial Pain center were enrolled. Patients' sleep conditions were evaluated with the Pittsburgh Sleep Quality Index (PSQI) questionnaire, and information on night-time sleep duration, napping duration and napping frequency was interviewed. TMD was diagnosed according to the Diagnostic Criteria for TMD protocol and stratified into myalgia (muscle pain), arthralgia (joint pain) and combined (muscle and joint pain) subgroups. The severity of TMD was measured with the Fonseca Anamnestic Index (FAI) questionnaire. Restricted cubic spline (RCS) regression models were established to explore relationships between sleep and painful TMD subgroups.

RESULTS

Patients with poor sleep quality (PSQI≥6) had higher FAI scores (median 60, p < .001) and higher proportions of painful TMDs. The myalgia subgroup had higher PSQI scores (median 8, p < .001) than the arthralgia subgroup. The RCS models indicated a non-linear relationship between night-time sleep duration and myalgia (p < .001), which was not observed in arthralgia. However, there were no significant findings concerning napping and painful TMD subgroups.

CONCLUSION

This study found that the association between sleep and TMD is mainly related to painful TMD conditions, which are associated with night-time sleep duration.

Age and Gender, but Not Pain are Associated with Pressure Pain Thresholds in Patients with Temporomandibular Disorders: A Cross-Sectional Study

Purpose

This study aims to explore the association of pressure pain thresholds (PPTs) with age, gender, and pain in patients with temporomandibular disorders (TMD).

Patients and Methods

A total of 301 TMD patients (248 female and 53 male) were recruited and classified into the high and low age groups according to their median age of 26 years. Patients' demographics, pain-related variables, TMD-related variables, and PPTs of both left and right temporomandibular joints (TMJs), masseter, and temporalis were collected.

Results

Pain duration and visual analog scale of pain (VAS) showed no significant correlations with PPTs (P>0.05). Multiple linear regression analysis revealed a significant positive association of PPTs of all six sites with males (β=0.41-0.72 kg·cm-2, 95% CI (0.19-0.38, 0.74-0.99), P<0.001), as well as with the high age group [β=0.28-0.36 kg·cm-2, 95% CI (0.07-0.20, 0.47-0.53), P<0.020]. Furthermore, PPTs of the left TMJ showed a significant negative association with left pain-related TMD (PT) [β=-0.21 kg·cm-2, 95% CI (-0.38, -0.04), P=0.026], but PPTs of the remaining sites did not show a significant association with PT (P>0.05). Stratified analysis showed that PPTs in females were associated with the high age group [β=0.25-0.37 kg·cm-2, 95% CI (0.04-0.20, 0.45-0.56), P<0.020] and that PPT of the left TMJ was associated with left PT [β=-0.21 kg·cm-2, 95% CI (-0.39, -0.03), P=0.043]. The remaining PPTs did not show a significant association with PT (P>0.05). In males, PPTs did not show significant correlations with age, PT and VAS (P>0.05).

Conclusion

PPTs in the orofacial region are associated with gender and age in TMD patients. Pain duration and intensity show no significant correlations with PPTs in TMD patients. Researchers and dentists should take age and gender into account when using PPTs as auxiliary diagnostic indicators for PT.

Is the risk of chronic pain after total temporomandibular joint replacement independent of its indications? A prospective cohort study

Chronic pain is a possible long-term complication after alloplastic temporomandibular joint reconstruction (TMJR). This study was developed to evaluate various subjective and objective measurements to determine the presence and degree of TMJ pain in patients treated with TMJR regardless of the indication for the operation. A prospective, single-centre study was performed. Data on 36 patients (56 TMJR) were collected preoperatively and at follow up two to three years postoperatively. The primary outcome variable was subjective TMJ pain (none/mild, moderate/severe) at follow up. The predictor variables were objective pressure pain thresholds (PPTs) at the ipsilateral joint(s) and muscle(s), functional parameters (incisal range of motion, maximum voluntary clenching), subjective oral health-related quality of life (OHRQoL), and demographic and surgical variables. The number of patients with moderate/severe pain decreased from 17 preoperatively to 10 at follow up. Self-reported TMJ pain was significantly reduced in the entire group (p = 0.001). Patients with moderate/severe pain at follow up were more restricted in their OHRQoL but did not differ in PPT and functional parameters from the no/mild pain group. Moderate/severe TMJ pain at follow up was associated with unilateral TMJR and more preoperative pain. This study provides preliminary evidence that despite good pain reduction in most patients, persistent pain after TMJR is common and, in rare cases, may even worsen regardless of the original diagnosis. At follow up there was a close relation between OHRQoL and TMJ pain. TMJ pain after TMJR cannot be confirmed by objective measurement methods (PPTs and functional parameters).

Temporomandibular disorders cases with high-impact pain are more likely to experience short-term pain fluctuations

Temporomandibular disorders (TMD) patients can present clinically significant jaw pain fluctuations which can be debilitating and lead to poor global health. The Graded Chronic Pain Scale evaluates pain-related disability and its dichotomous grading (high/low impact pain) can determine patient care pathways and in general high-impact pain patients have worse treatment outcomes. Individuals with low-impact TMD pain are thought to have better psychosocial functioning, more favorable disease course, and better ability to control pain, while individuals with high-impact pain can present with higher levels of physical and psychological symptoms. Thereby, there is reason to believe that individuals with low- and high-impact TMD pain could experience different pain trajectories over time. Our primary objective was to determine if short-term jaw pain fluctuations serve as a clinical marker for the impact status of TMD pain. To this end, we estimated the association between high/low impact pain status and jaw pain fluctuations over three visits (≤ 21-day-period) in 30 TMD cases. Secondarily, we measured the association between jaw pain intensity and pressure pain thresholds (PPT) over the face and hand, the latter measurements compared to matched pain-free controls (n = 17). Jaw pain fluctuations were more frequent among high-impact pain cases (n = 15) than low-impact pain cases (n = 15) (OR 5.5; 95% CI 1.2, 26.4; p value = 0.033). Jaw pain ratings were not associated with PPT ratings (p value > 0.220), suggesting different mechanisms for clinical versus experimental pain. Results from this proof-of-concept study suggest that targeted treatments to reduce short-term pain fluctuations in high-impact TMD pain is a potential strategy to achieve improved patient perception of clinical pain management outcomes.

Pressure pain thresholds in office workers with chronic neck pain: A systematic review and meta-analysis

OBJECTIVES

The purpose of this study was to (a) compare pressure pain threshold (PPT) values between office workers with chronic neck pain and asymptomatic controls; (b) establish reference PPT values in chronic neck pain; and (c) evaluate associations between PPTs and pain intensity, and disability.

METHODS

Seven English/Portuguese databases were searched for relevant literature. Studies investigating adult office workers (age >18 years) with chronic neck pain were included if PPTs were an outcome. The risk of bias was assessed using the Downs and Black checklist. Meta-analysis was conducted if a cluster contained at least two studies reporting the same PPTs.

RESULTS

Ten high quality, two low quality, and one poor quality studies were included. The meta-analysis revealed decreased PPT values in the upper trapezius, extensor carpi ulnaris, and tibialis anterior in office workers with chronic neck pain when compared with healthy workers, without a statistical difference (p > 0.05). The PPT reference value in the upper trapezius was 263 kPa (95% confidence interval [CI] = 236.35 to 289.70), and 365 kPa (95% CI = 316.66 to 415.12) for the tibialis anterior in office workers with chronic neck pain. No correlations were found between the upper trapezius PPT and pain intensity and disability.

CONCLUSION

This meta-analysis found that all the PPT measurements were not significantly reduced in office workers with chronic neck pain compared with healthy workers. These assumptions were based on a small sample of existing studies, and therefore further studies are necessary to quantify the differences in PPTs. Hypersensitivity PPT reference values are proposed for localized and extrasegmental sites in office workers with chronic neck pain.

Effect of short-term increase in occlusal vertical dimension on masticatory muscle electrical activities and pressure-to-pain threshold: A crossover clinical study

STATEMENT OF PROBLEM

Increasing the occlusal vertical dimension (OVD) is a common procedure in clinical practice. However, few studies have assessed the short-term influence of an increased OVD on the masticatory muscles.

PURPOSE

The purpose of this crossover clinical study was to investigate the effect of increased OVD on the electrical activity of masticatory muscles and the pressure-to-pain threshold (PPT) in asymptomatic participants.

MATERIAL AND METHODS

Twenty asymptomatic participants (22.7 ±2.39 years of age; 10 men, 10 women) were submitted to an increase in OVD by using interocclusal devices of different thicknesses (3- and 6-mm) for 24 hours. Masticatory muscle activity was assessed with electromyography (EMG), expressed in microvolts (μV), while the participants masticated 2 pieces of latex of different consistency (latex S and H) with and without the device. The PPT was measured with a digital algometer before and after the mastication. The results were assessed by using analysis of variance (ANOVA) and the Tukey honestly significant difference (HSD) test (α=.05).

RESULTS

The change of OVD did not significantly affect the electrical activity of the muscles. The latex of hard consistency (latex H) showed higher electrical activity values than the soft texture (latex S). For the working side anterior temporal muscle, a change in the PPT was detected on the day the 6-mm-device was inserted, but for the other muscles, device thickness and latex mastication did not change the PPT.

CONCLUSIONS

For a short time, an increase in occlusal vertical dimension did not affect the electrical activity in the masticatory muscles or pressure-to-pain threshold in asymptomatic participants.

Comparison of the Efficacy of Botulinum Toxin, Local Anesthesia, and Platelet-Rich Plasma Injections in Patients With Myofascial Trigger Points in the Masseter Muscle

PURPOSE

Masticatory myofascial trigger points (TrP) are one of the major causes of nondental pain in the orofacial region. Intramuscular injections are considered the first-line treatment for myofascial TrPs. The objectives of this study were to evaluate and compare the effectiveness of local anesthesia (LA), botulinum toxin (BTX), and platelet-rich plasma (PRP) injections for the treatment of myofascial TrPs in the masseter muscle.

METHODS

In this retrospective study, the sample was composed of patients with myofascial TrPs in masseter muscle who were treated between 2016 and 2019. Patients were divided into 3 groups according to treatment methods: group I (LA injection), group II (BTX injection), and group III (PRP injection). Primary outcome variable was the average pain level at rest and while chewing, and pressure pain intensity (PPI), Jaw Functional Limitation Scale (JFLS) value, and quality-of-life (measured using Oral Health Impact Profile-14 (OHIP-14)) were secondary outcomes. The outcome variables were assessed at diagnosis, and 1, 3, and 6 months post-treatment.

RESULTS

The study consisted of 82 patients (group I, 27; group II, 26; group III, 29). At 1 and 3 months, improvement in all parameters was recorded in all groups. Groups I and II showed superior improvement in all parameters compared with group III at 3 months. Improvements in VAS pain, JFLS, and OHIP-14 values were significantly better in group II than group I at 3 months (P = .009; P = .004; P = .002). At 6 months, significant improvement in VAS pain, JFLS, and OHIP-14 (P = .008; P < .001; P < .01) values was recorded only in group II.

CONCLUSIONS

All procedures successfully improved the symptoms of TrPs in the masseter muscle at 1 and 3 months. However, BTX injection seemed superior at the 3-month follow-up and remained effective up to 6 months.

1H-NMR-Based salivary metabolomics from females with temporomandibular disorders - A pilot study

Although temporomandibular disorder (TMD) is the second most common musculoskeletal disorder in the general population, the disease is multifactorial and presents symptoms common to other conditions which misdiagnosis can lead to treatment failure. In this case-control study, we performed, for the first time, a high-resolution ¹H-nuclear magnetic resonance spectroscopy metabolomic analysis of the saliva of 26 women with TMD of muscular origin (experimental group [EG]) at the beginning (EG-pre) and at the end (EG-post) of a conservative treatment, and of 27 normal women (control group [CG]) to identify a metabolic signature for TMD. One-way analysis of variance showed changes in the concentration of phenylacetate, dimethylamine, maltose, acetoin, and isovalerate. Partial least-square discriminant analysis showed that metabolite signals did not overlap in CG X EG-pre and EG-pre X EG-post, but overlapped in CG X EG-post. The area under the receiver operating characteristic curve was 1 in CG X EG-pre (95% CI, 1.000-1.000; p < 0.002), 0.993 in EG-pre X EG-post (95% CI, 0.963-1.000), and 0.832 in CG X EG-post (95% CI, 0.699-0.961). These results suggest that the metabolomic profiles of women with and without TMD differ, while after treatment there is a lower distinction and slight tendency towards overlapping between CG and EG-post compared to pre treatment. We also found that phenylacetate, dimethylamine, maltose, acetoin, and isovalerate are potential biomarkers for TMD of muscular origin.

Myalgia in 30 Patients with Suspected Myopathy

Background: In patients with neuromuscular disorder, only little data of myalgia frequency and characterization exists. To date, only a weak correlation between pain intensity and pressure pain threshold has been found, and it remains enigmatic whether high pain intensity levels are equivalent to high pain sensitivity levels in neuromuscular disorders. Methods: 30 sequential patients with suspected neuromuscular disorder and myalgia were analyzed with regard to myalgia characteristics and clinical findings, including symptoms of depression and anxiety and pain- threshold. Results: A neuromuscular disorder was diagnosed in 14/30 patients. Muscular pain fasciculation syndrome (MPFS) without evidence for myopathy or myositis was diagnosed in 10/30 patients and 6/30 patients were diagnosed with pure myalgia without evidence for a neuromuscular disorder (e.g., myopathy, myositis, MPFS, polymyalgia rheumatica). Highest median pain scores were found in patients with pure myalgia and polymyalgia rheumatica. Pressure pain threshold measurement showed a significant difference between patients and controls in the biceps brachii muscle. Conclusion: Only a weak correlation between pain intensity and pressure pain threshold has been suggested, which is concordant with our results. The hypothesis that high pain intensity levels are equivalent to high pain sensitivity levels was not demonstrated.

Short-term effects of two deep dry needling techniques on pressure pain thresholds and electromyographic amplitude of the lumbosacral multifidus in patients with low back pain - a randomized clinical trial

Objectives: The purpose of this study was to compare the effects of deep dry needling (DN) with and without needle manipulation on pressure pain thresholds (PPTs) and electromyographic (EMG) amplitude of the lumbosacral multifidus (LM) in adults with low back pain (LBP). Methods: Participants were randomized into two treatment groups: with needle manipulation (n = 21) and without needle manipulation (n = 21). All participants received a single session of the assigned DN intervention. PPTs and EMG amplitude of the LM muscle were collected three times: before DN, immediately after DN, and one week after DN. Results: The needle manipulation group had a significantly greater increase in PPT immediately after the intervention and at the one-week follow-up as compared to the no needle manipulation group. The increase of PPT in the needle manipulation group was significant immediately after the intervention, and the increase remained significant at the one-week follow-up. However, there was no significant difference in EMG amplitude of the LM muscle between groups across the three time points. Discussion: Deep DN with needle manipulation appeared to reduce mechanical pressure sensitivity more than DN without manipulation for patients with LBP. Although a single session of DN could reduce pressure pain sensitivity, it may not be sufficient to improve LM muscle function. Level of Evidence: 1b. Trial registration numbers: NCT03970486.

Association between Physiological and Subjective Aspects of Pain and Disability in Post-Stroke Patients with Shoulder Pain: A Cross-Sectional Study

Background: Patients often experience pain as a result of a stroke. However, the mechanism of this pain remains uncertain. Our aim was to investigate the relationship between pressure pain thresholds (PPTs) and disability pain in patients with hemiplegic shoulder pain (HSP). Methods: Twenty-six post-stroke patients (age 53.35 ± 13.09 years) and healthy controls (54.35 ± 12.37 years) participated. We investigated spontaneous shoulder pain, disability pain perception through the shoulder pain and disability index (SPADI), and the PPTs over joint C5–C6, upper trapezius, deltoid, epicondyle, second metacarpal, and tibialis anterior, bilaterally. Results: The analysis of variance (ANOVA) showed significant differences in pain between groups (p < 0.001) and differences in the SPADI (p < 0.001) between groups but not between sides for PPTs over deltoid (group: p = 0.007; side: p = 0.750), epicondyle (group: p = 0.001; side: p = 0.848), and tibialis anterior (group: p < 0.001; side: p = 0.932). Pain in the affected arm was negatively associated with PPTs over the affected epicondyle (p = 0.003) and affected tibialis anterior (p = 0.009). Pain (SPADI) appeared negatively correlated with PPTs over the affected epicondyle (p = 0.047), and disability (SPADI) was negatively associated with PPTs over the affected tibialis anterior (p = 0.041). Conclusions: Post-stroke patients showed a relationship between widespread pressure pain hypersensitivity with lower PPT levels and pain disability perception, suggesting a central sensitization mediated by bilateral and symmetric pain patterns.

Somatosensory profiles of patients with chronic myogenic temporomandibular disorders in relation to their painDETECT score

BACKGROUND

The purpose of this study was to characterize patients with chronic temporomandibular disorders (TMD) in terms of existing hyperalgesia against cold, heat and pressure.

METHODS

The extent of hyperalgesia for pressure and thermal sensation in TMD patients was determined by the use of the painDETECT questionnaire ("Is cold or heat in this area occasionally painful?" "Does slight pressure in this area, e.g., with a finger, trigger pain?") and experimental somatosensory testing against thermal and pressure stimuli (Quantitative Sensory Testing; QST). In addition, we explored psychological comorbidity among the chronic TMD patients (hospital anxiety and depression scale, HADS-D and coping strategies questionnaire, CSQ).

RESULTS

Nineteen patients with chronic TMD and 38 healthy subjects participated in the study. N = 12 patients had a painDETECT score ≤ 12, n = 3 patients had a painDETECT score of 13-18 and n = 4 patients had a painDETECT score ≥ 19. TMD patients with painDETECT scores ≥19 had moderately, strong or very strong enhancement of thermal and pressure pain perception, whereas patients with painDETECT scores 13-18 and ≤ 12 responded these questions with "never", "hardly noticed" or "slightly painful" (p < 0.05-0.01). With increasing painDETECT scores we found increased hyperalgesia for pressure (p < 0.01) and thermal stimuli (p < 0.05) in QST. The patients with a painDETECT score ≥ 19 showed increased signs of anxiety (p < 0.05), depression (p < 0.01), praying and hoping (p < 0.05).

CONCLUSION

The present study has shown that the PainDETECT questionnaire can be a helpful additional diagnostic tool. Together with QST, the PainDETECT questionnaire detected hyperalgesia for pressure and thermal sensation. Therefore the PainDETECT questionnaire is helpful to decide which TMD patients should undergo QST.

Test-retest reliability of a new technique with pressure algometry applied to teeth in healthy Chinese individuals

Pressure pain thresholds (PPTs) have been shown to be useful measures of mechanical pain sensitivity in deep tissues. However, clinical methods for measuring mechanical allodynia or hyperalgesia in teeth have not been reported. The aim of this study was to assess the reliability of PPTs in periodontal ligament of healthy Chinese participants. Twenty healthy young adults participated. Pressure pain thresholds were measured at six teeth and in two directions. The tests included three consecutive trials, in two separate sessions, which were performed on the first day by one examiner. After 1-3 wk, an identical protocol was carried out by two examiners, also in two separate sessions. There were no significant differences between repeated measures for all teeth. The PPTs had excellent reliability with high intraclass coefficients (ICCs) across different sessions (ICC: 0.871-0.956), days (ICC: 0.879-0.951), and examiners (ICC: 0.845-0.950). Pressure pain thresholds applied to the teeth have excellent intra- and inter-examiner agreement in healthy participants. This method may be proposed as an easy and reliable technique to assess mechanical pain sensitivity (e.g. mechanical allodynia and hyperalgesia) in the periodontal ligament, which is associated with endodontic or periodontal conditions.