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

Women are worse off in developing and recovering from temporomandibular disorder symptoms

Decision-making for temporomandibular disorders (TMDs) is reported being a clinical challenge, partly due to uncertainities in assessment of long-term prognosis. Therefore, our aim was to explore variations over time in TMD symptoms and possible sex or age differences. In this cohort study, data were prospectively collected 2010-2017 from the general population in Västerbotten, Northern Sweden. Adults were eligible if they had undergone at least two routine dental check-ups that included screening for TMDs (3Q/TMD) from which states were defined as absence or presence of TMD pain and/or jaw catching/locking. The rate of transitions was estimated between TMD states within a time span of one year. A total of 94,769 individuals were included (49.9% women) with 205,684 repeated visits and 9,006 state transitions recorded over the 8-year period. Compared to men, women had higher rates of transitions from no TMDs to any TMD symptoms. Furthermore, women had a lower rate of transition from TMD pain only to no TMDs. The finding of a poorer prognosis in women, as well as previously reported potential gender differences in pain perception and reporting, reinforces that gender differences should be accounted for in the treatment planning stage for patients with onset of TMDs.

The Contribution of Sleep Quality and Psychological Factors to the Experience of Within-Day Pain Fluctuations Among Individuals With Temporomandibular Disorders

We assessed the impact of day-to-day sleep quality and psychological variables (catastrophizing, negative affect, and positive affect) to within-day pain fluctuations in 42 females with painful temporomandibular disorders (TMD) using electronic diaries. More specifically, we examined the contribution of these variables to the likelihood of experiencing pain exacerbations defined as 1) an increase of 20 points (or more) in pain intensity on a 0 to 100 visual analog scale from morning to evening, and/or 2) a transition from mild-to-moderate pain over the course of the day; and pain decreases defined as 3) a decrease of 20 points (or more) in pain intensity (visual analog scale) from morning to evening, and/or 4) a reduction from moderate-to-mild pain over the day. The results indicated significantly main effects of sleep on both pain exacerbation outcomes (both P's < .05), indicating that nights with better sleep quality were less likely to be followed by clinically meaningful pain exacerbations on the next day. The results also indicated that days characterized by higher levels of catastrophizing were associated with a greater likelihood of pain exacerbations on the same day (both P's < .05). Daily catastrophizing was the only variable significantly associated with within-day pain decrease indices (both P's < .05). None of the other variables were associated with these outcomes (all P's > .05). These results underscore the importance of addressing patients' sleep quality and psychological states in the management of painful TMD. PERSPECTIVE: These findings highlight the significance of sleep quality and pain catastrophizing in the experience of within-day pain fluctuations among individuals with TMD. Addressing these components through tailored interventions may help to alleviate the impact of pain fluctuations and enhance the overall well-being of TMD patients.

Impact of chronic painful temporomandibular disorders on quality of life

Temporomandibular Disorders (TMDs) are pathologies based on multifactorial etiology and a biopsychosocial model, where anxiety becomes one of the most important psychological factors as it is the most frequent symptom presented in most of the population at some point in life. Taking into account the need for a multidisciplinary approach, we set out to evaluate the possible impact of orofacial pain on patients' quality of life. In this study, the sample population FROM the Medical School of the University of Coimbra (Portugal) was evaluated using two tools: Diagnostic Criteria for Temporomandibular Disorder (DC/TMD) and an adaptation of the West Haven-Yale Multidimensional Pain Inventory. Participants with Chronic Pain for more than three months and diagnosed with TMD were included in the research. The quality of life and pain intensity of participants with Chronic Orofacial Pain were assessed using questionnaires. Subsequently, statistical analysis were conducted. A total sample of 122 participants was selected. A statistically significant association was observed between an increase in pain intensity and a decrease in quality of life in three aspects we considered (daily activity, general mood and anxiety) and we demonstrated that pain intensity is significantly associated with a decrease in quality of life.

Females with painful temporomandibular disorders present higher intracortical facilitation relative to pain-free controls

OBJECTIVES

This study aimed to investigate cortical excitability differences in the primary motor cortex (M1) hand representation between individuals with temporomandibular disorders (TMD) and healthy controls. We assessed resting motor thresholds, motor-evoked potentials (MEPs), intracortical inhibition, and intracortical facilitation and explored potential associations with clinical and psychosocial characteristics in the TMD group.

MATERIALS AND METHODS

We recruited 36 female participants with TMD and 17 pain-free controls. Transcranial magnetic stimulation (TMS) was used to assess M1 cortical excitability. Correlations between clinical and psychosocial factors and cortical excitability measures were also evaluated.

RESULTS

Patients with TMD showed significantly higher intracortical facilitation at 12 ms (z = 1.98, p = 0.048) and 15 ms (z = 2.65, p = 0.008) when compared to controls. Correlations revealed associations between intracortical facilitation and pain interference, sleep quality, depressive symptoms, and pain catastrophizing in the TMD group.

CONCLUSIONS

Females with TMD exhibit heightened motor cortex intracortical facilitation in the hand representation, potentially indicating altered cortical excitability beyond the motor face area. This suggests a role for cortical excitability in TMD pathophysiology, influenced by psychosocial factors.

CLINICAL RELEVANCE

Understanding cortical excitability in TMD may inform targeted interventions. Psychosocial variables may play a role in cortical excitability, emphasizing the multidimensional nature of TMD-related pain. Further research is needed to confirm and expand upon these findings, with potential implications for the management of TMD and related pain conditions.

Orofacial anti-hypernociceptive effect of citral in acute and persistent inflammatory models in rats

Orofacial pain has significant psychological and physiological effects. Citral (3,7-dimethyl-2,6-octadienal) is the main component of Cymbopogon citratus (DC) Stapf, an herb with analgesic properties. Although citral has been considered a potent analgesic, its putative effects on orofacial pain are still unknown.

OBJECTIVE

The objective of this study is to test the hypothesis that citral modulates orofacial pain using two experimental models: formalin-induced hyperalgesia in the vibrissae area and during persistent temporomandibular hypernociception using Complete Freund's Adjuvant - CFA test.

METHODS

For the formalin test, citral (100 and 300 mg/kg, oral gavage) or its vehicle (Tween 80, 1 %) were given 1 h before the formalin injection subcutaneously (sc) into the vibrissae area. For the CFA model, we analyzed the prophylactic (100 mg/kg of citral by oral gavage, 1 h before CFA injection) and the chronic therapeutic (citral treatment 1-hour post-CFA injection and daily post-CFA injection) effect of citral or its vehicle in animals treated with CFA for 8 days.

RESULTS

Citral caused a decrease in formalin-induced local inflammation and the time spent performing nociceptive behavior in a dose-dependent fashion. Similarly, prophylactic and therapeutic citral treatment decreased the CFA-induced persistent mechanical hypernociception in the temporomandibular area.

CONCLUSION

Our data strengthen the notion that citral plays a powerful antinociceptive role by decreasing orofacial hypernociception in formalin and CFA models.