Pulp Sensitivity: Influence of Sex, Psychosocial Variables, COMT Gene, and Chronic Facial Pain

The clinical outcomes of vital intact teeth close to large cystic lesions of endodontic origin: A prospective clinical study

AIM

To evaluate the indication of the endodontic treatment for vital intact teeth with the root apex involved in large radicular cystic lesions of endodontic origin.

METHODOLOGY

This prospective cohort study enrolled healthy participants with radicular cysts of endodontic origin and with the root apex of vital intact teeth involved in the bone defect, as determined by cone beam computed tomography (CBCT). Thirty-two sound vital teeth were analysed by thermal (TPT) and electric pulp tests (EPT) before surgery (T0) and 1 week (T1), 2 weeks (T2), 3 months (T3) and 6 months (T4) post-surgery. Student's t-test (p < .05) was used to compare the EPT values at baseline and T4. anova (p < .05) was used to analyse the EPT variations for all maxillary and mandibular teeth. McNemar test (p < .05) was used to compare the results according to variation in EPT values gathering by variation, no variation and no response.

RESULTS

At T1, 75 and 65.7% of teeth responded positively whilst 25 and 34.3% did not respond to EPT and TPT, respectively. The variation of the EPT values between T0 and T1 was observed for 50.0% of teeth, whilst no variation was noticed in 25.0% of teeth. At T4, 90.6 and 87.5% of teeth responded positively whilst 9.4 and 12.5% did not respond to EPT and TPT, respectively. At T4, variation of the EPT values between T0 and T4 was observed for 28.1%, whilst no variation was noticed in 62.5% of teeth. There were no statistical differences in EPT results between T0 and T4 (p > .05), but significant differences were observed for EPT values between T1 and T4 (p < .05), and between mandibular and maxillary teeth. The pulp sensibility of maxillary teeth worsened after surgery, before reverting progressively to T0 values, whilst no statistically significant differences were observed for mandibular teeth at the different time points.

CONCLUSIONS

These data support the inconsistence of the prophylactic endodontic treatment in healthy vital teeth with apex involvement in large cystic lesions of endodontic origin. Post-surgery follow-up with TPT and EPT is recommended to assess pulp status.

Are catechol-O-methyltransferase gene polymorphisms genetic markers for pain sensitivity after all? - A review and meta-analysis

The catechol-O-methyltransferase (COMT) gene has arguably been the designated pain sensitivity gene for nearly two decades. However, the literature provides inconsistent evidence. We performed several meta-analyses including k = 31 samples and n = 4631 participants thereby revealing small effects of rs4680 on pain thresholds in fibromyalgia, headache and across chronic pain conditions. Moreover, rs4680 effects were found across pain patients when affected, but not unaffected, body sites were assessed. No effect was detected for any other SNP investigated. Importantly, our results corroborate earlier findings in that we found a small effect of COMT haplotypes on pain sensitivity. Our review and meta-analysis contribute to the understanding of COMT-dependent effects on pain perception, provide insights into research issues and offer future directions. The results support the theory that rs4680 might only impact behavioural measures of pain when descending pain modulatory pathways are sufficiently challenged. After all, COMT polymorphisms are genetic markers of pain sensitivity, albeit with some limitations which are discussed with respect to their implications for research and clinical significance.

Comparison of pulp sensibility test responses in normotensive and hypertensive individuals: A clinical study

Background

Pulp sensibility testing is an essential part of the diagnostic process in the assessment of pulpal health. Several lines of evidence suggest an interaction between control of blood pressure and pain regulatory mechanisms.

Aim

The aim of the study is to compare pulp sensibility test responses in normotensive and hypertensive individuals.

Materials and Methods

Ninety-eight patients participated in the study, with 49 individuals each in the hypertensive and normotensive groups. A minimum of 4 and maximum of 8 sound teeth were included in the study each from the anterior, premolar, and molar, i.e., 4 teeth from either arch. A total of 832 teeth were tested. The value and time when the responses evoked for electric pulp test (EPT) and cold test were recorded respectively.

Statistical Analysis

For intergroup and intragroup analyses, independent t-test and paired t-test were utilized.

Results

A statistically significant difference was noted in values for EPT as well as cold test responses when both the groups were compared (P < 0.01). Higher values were obtained with the hypertensive group.

Conclusion

Patients with established hypertension showed an increased threshold to electric pulp testing and cold stimulus as compared to normal healthy individuals.

Relationship between the difference in electric pulp test values and the diagnostic type of pulpitis

BACKGROUND

According to the diagnosis criteria of the American Association of Endodontists (AAE), sensitive responses to cold and/or heat tests of suspected teeth compared with those of control teeth can be used for the diagnosis of pulpitis, but the role of electric pulp test (EPT) is not mentioned. It is believed that EPT has some limitations in determining the vitality of the pulp. The aim of this study was to explore the association between the difference in EPT values and the differential diagnoses of reversible pulpitis (RP) and symptomatic irreversible pulpitis (SIRP) caused by dental caries.

METHODS

A total of 203 cases with pulpitis caused by dental caries were included. A diagnosis of pulpitis was made on the basis of the diagnostic criteria of AAE. Patient demographic and clinical examination data were collected. The EPT values of the suspected teeth and control teeth were measured, and the differences between them were calculated. The correlation between the difference in the EPT values and diagnosis of pulpitis was analyzed using univariate and multivariate logistic regression.

RESULTS

In the 203 cases (78 males and 125 females; 115 cases of RP, 88 cases of SIRP; 9 anterior teeth, 59 premolars, and 135 molars), the mean patient age was 34.04 ± 13.02 (standard deviation) years. The unadjusted (crude) model, model 1 (adjusted for age), model 2 (adjusted for age and sex), and model 3 (adjusted for age, sex, and tooth type) were established for the statistical analyses. In model 3 [odds ratio (OR) = 1.025; 95% confidence interval (CI) 1.002-1.050; P = 0.035], the difference in EPT values between RP and SIRP was statistically significant. However, the areas under the curve of predictive probability of the crude model, model 1, model 2, and model 3 were 0.565, 0.570, 0.585, and 0.617, respectively, showing that the model accuracy was low. The P-value for the trend in differences between the EPT values as a categorical variable showed that the differences in the EPT values, comparing RP and SIRP, were not statistically significant.

CONCLUSIONS

Based on the present data, the difference in EPT values was not sufficient to differentiate RP from SIRP.

Changes in pulp sensitivity across the menstrual cycle in healthy women and women with temporomandibular disorders

BACKGROUND

Menstrual cycle may contribute to experimental pain measures in healthy women and women with chronic pain.

OBJECTIVES

The present study aimed to investigate variation in pulp sensitivity across the menstrual cycle in healthy women and women with temporomandibular disorders (TMD) and to explore the effect of TMD pain and psychosocial variables on the pulp response.

METHODS

This longitudinal study involved 47 regularly menstruating women aged 20-45, 24 healthy and 23 with diagnosed painful TMD. The electric and cold stimuli were performed by electric pulp tester and refrigerant spray, respectively, on mandibular lateral incisors, in five menstrual phases (menstrual, follicular, periovulatory, luteal and premenstrual). Research Diagnostic Criteria for TMD were used to assess TMD, chronic pain, depression and somatisation. Regression analysis was performed to investigate the effect of the predictor variables on the pulp sensitivity.

RESULTS

Significant phase-related differences were observed for pain intensity to cold stimuli. Higher pain sensitivity was reported in menstrual in comparison with luteal phase (P = .019) among healthy women, and in menstrual in comparison with follicular (P = .033), periovulatory (P = .003) and luteal (P = .007) phases in TMD women. No significant differences were recorded for electric stimuli. Regression analysis identified depression as the determinant of cold and electric response in menstrual phase, regardless of age and presence of TMD.

CONCLUSION

Menstrual phase in healthy and TMD women with regular menstrual cycle is characterised with higher pulp sensitivity to cold stimuli. Depressive symptoms independently influence pulp response in this phase.

COMT rs4818, pain sensitivity and duration, and alveolar bone grafting of oral clefts

PURPOSE

Verifying whether the mutation in COMT rs4818 could be involved in pain modulation.

METHODS

Thirty-two individuals born with cleft lip and palate that underwent bone graft from the iliac crest bone were assessed at 12, 24, 48, 72 h, and 7 days regarding their pain experience using a visual analogic scale. DNA from each participant was collected from saliva samples, and genotyping of rs4818 was performed using TaqMan chemistry. Overrepresentation of rs4818 alleles was tested using chi-square or Fisher's exact tests with an alpha of 0.05.

RESULTS

Of the 32 individuals, eighteen reported long pain duration, nine reported high pain intensity, and fourteen low pain intensity up to 48 h. No differences were found in the distribution of individuals depending on the reported pain by sex (p = 0.12), age (p = 0.42), or cleft type (p = 0.5). The distribution of COMT r4818 alleles was different depending on the intensity and duration of pain. Carriers of the C wild-type allele were four times more likely to show high pain intensity and duration (odds ratio = 4.29, 95% confidence interval 1.13-16.18), meaning that the G variant allele is protective.

CONCLUSION

COMT rs4818 is associated with postoperative pain after alveolar bone grafting.

Biomarkers in Temporomandibular Disorder and Trigeminal Neuralgia: A Conceptual Framework for Understanding Chronic Pain

In this review, we will explore the use of biomarkers in chronic pain, using the examples of two prototypical facial pain conditions: trigeminal neuralgia and temporomandibular disorder. We will discuss the main categories of biomarkers and identify various genetic/genomic, molecular, neuroradiological, and psychophysical biomarkers in both facial pain conditions, using them to compare and contrast features of neuropathic, nonneuropathic, and mixed pain. By using two distinct model facial pain conditions to explore pain biomarkers, we aim to familiarize readers with different types of biomarkers currently being studied in chronic pain and explore how these biomarkers may be used to develop new precision medicine approaches to pain diagnosis, prognosis, and management.