Applications of sensory and physiological measurement in oral-facial dental pain

Involvement of Oxidative Stress and Nutrition in the Anatomy of Orofacial Pain

Pain is a very important problem of our existence, and the attempt to understand it is one the oldest challenges in the history of medicine. In this review, we summarize what has been known about pain, its pathophysiology, and neuronal transmission. We focus on orofacial pain and its classification and features, knowing that is sometimes purely subjective and not well defined. We consider the physiology of orofacial pain, evaluating the findings on the main neurotransmitters; in particular, we describe the roles of glutamate as approximately 30-80% of total peripheric neurons associated with the trigeminal ganglia are glutamatergic. Moreover, we describe the important role of oxidative stress and its association with inflammation in the etiogenesis and modulation of pain in orofacial regions. We also explore the warning and protective function of orofacial pain and the possible action of antioxidant molecules, such as melatonin, and the potential influence of nutrition and diet on its pathophysiology. Hopefully, this will provide a solid background for future studies that would allow better treatment of noxious stimuli and for opening new avenues in the management of pain.

Orofacial Pain Management: An Overview of the Potential Benefits of Palmitoylethanolamide and Other Natural Agents

Pain is the most common symptom that dentists are confronted with, whether acute (pulpitis, acute periodontitis, post-surgery, etc.) or chronic diseases, such as periodontitis, muscle pain, temporomandibular joint (TMJ) disorders, burning mouth syndrome (BMS), oral lichen planus (OLP) and others. The success of therapy depends on the reduction in and management of pain through specific drugs, hence the need to analyze new pain medications with specific activity, which are suitable for long-term use, with a low risk of side effects and interactions with other drugs, and capable of leading to a reduction in orofacial pain. Palmitoylethanolamide (PEA) is a bioactive lipid mediator, which is synthesized in all tissues of the body as a protective pro-homeostatic response to tissue damage and has aroused considerable interest in the dental field due to its anti-inflammatory, analgesic, antimicrobial, antipyretic, antiepileptic, immunomodulatory and neuroprotective activities. It has been observed that PEA could play a role in the management of the pain of orofacial origin, including BMS, OLP, periodontal disease, tongue a la carte and temporomandibular disorders (TMDs), as well as in the treatment of postoperative pain. However, actual clinical data on the use of PEA in the clinical management of patients with orofacial pain are still lacking. Therefore, the main objective of the present study is to provide an overview of orofacial pain in its many manifestations and an updated analysis of the molecular pain-relieving and anti-inflammatory properties of PEA to understand its beneficial effects in the management of patients with orofacial pain, both neuropathic and nociceptive in nature. The aim is also to direct research toward the testing and use of other natural agents that have already been shown to have anti-inflammatory, antioxidant and pain-relieving actions and could offer important support in the treatment of orofacial pain.

Pain and discomfort perception during miniscrew-anchored maxillary protraction: secondary data analysis of a randomized clinical trial

OBJECTIVES

To compare the perception of pain and discomfort of patients and guardians during treatment between miniscrew-anchored maxillary protraction (MAMP) therapy using Hybrid (HH) and Conventional Hyrax (CH) expanders.

MATERIALS AND METHODS

Group HH was composed of 18 subjects (8 female, 10 male; initial age: 10.80 years) with Class III malocclusion treated with a hybrid expander in the maxilla and two miniscrews in the anterior region of the mandible. Class III elastics were used from maxillary first molar to mandibular miniscrews. Group CH was composed of 14 subjects (6 female, 8 male; initial age: 11.44 years) treated with a similar protocol except for conventional Hyrax expander. Pain and discomfort of patients and guardians were assessed using a visual analog scale immediately after placement (T1), after 24 hours (T2), and 1 month after appliance installation (T3). Mean differences (MD) were obtained. Intergroup and intragroup timepoint comparisons were performed using independent t-tests, analysis of variance for repeated measures and Friedman test (P < 5%).

RESULTS

Both groups demonstrated similar levels of pain and discomfort with a significant decrease after 1 month of appliance placement (MD: 4.21; P = .608). Compared to patient perceptions, guardians reported a higher level of pain and discomfort at all timepoints (MD, T1: 13.91, P < .001; T2: 23.15, P < .001; T3: 9.35, P = .008).

CONCLUSIONS

MAMP therapy with HH and CH produced similar levels of pain and discomfort after appliance installation until 1 month after treatment. Pain and discomfort may not influence the choice between HH and CH expanders.

Pain perception genes, asthma, and oral health: A reverse genetics study

Pain is an experience of a subjective nature, interpreted in a personal way and according to an extensive palette of factors unique to each individual. Orofacial pain can be acute or chronic and it is usually the main reason for the patient to seek dental care. Pain perception varies widely among individuals. This variability is considered a mosaic of factors, which include biopsychosocial factors and genetic factors. Understanding these differences can be extremely beneficial for pain management in a personalized and more efficient way. We performed association studies to investigate phenotypes associated with genetic markers in pain-related genes in two groups of patients who received more or less anesthesia during dental treatment. The study group was comprised of 1289 individuals participating in the Dental Registry and DNA Repository Project (DRDR) of the University of Pittsburgh, with 900 participants in the group that received the most anesthesia and 389 constituting the comparison group that received less anesthesia. We tested 58 phenotypes and genotypic data of seven SNPs in genes that are associated with pain perception, pain modulation and response to drugs used in pain treatment: COMT (rs4818 and rs6269), GCH1 (rs3783641), DRD2 (rs6276), OPRM1 (rs1799971), SCN9A (rs6746030) and SCN10A (rs6795970). The analysis revealed a protective effect of rs1799971 on asthma in the total sample. rs3783641 was associated with salivary secretion disorders in females who received more anesthesia. rs1799971 was also associated with periodontitis in Whites who received less anesthesia. rs4818 was associated with disease and other tongue conditions in the group composed of Blacks who received less anesthesia. In conclusion, our study implicated variants in pain-related genes in asthma and oral phenotypes.

Do Computerized Delivery System Promote Less Pain and Anxiety Compared to Traditional Local Anesthesia in Dental Procedures? A Systematic Review of the Literature

PURPOSE

The aim of this study is to assess whether the use of computerized devices to deliver local anesthesia results in less pain and anxiety compared to traditional anesthesia in adult dental procedures.

METHODS

This review was registered at PROSPERO (CRD 42021265046), based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and was structured according to the PICO strategy. The studies were selected based on eligibility criteria, and data were collected by 1 author and reviewed by another.

RESULTS

Nine of the 10 studies included were randomized controlled trials. Differences related to pain and anxiety were observed, which favored computerized techniques; however, caution should be exercised when interpreting these results due to differences in assessment methods. The studies used different local anesthetics, including 2% lidocaine, 4% articaine, or 3% mepivacaine with epinephrine diluted 1:80,000 to 1:200,000. A total of 560 patients were evaluated.

CONCLUSIONS

Computerized anesthesia devices yielded better results than conventionally delivered anesthesia after qualitative evaluation. Nevertheless, conventional anesthesia is widely used, safe, and effective. Due to the heterogeneity among the included studies, it is strongly recommended that new randomized clinical trials using well-defined methodologies be performed to improve the quality of evidence regarding this topic.

Tooth hypersensitivity associated with paresthesia after inferior alveolar nerve injury: case report and related neurophysiology

Inferior alveolar nerve (IAN) injury is usually caused by stretching or crushing of the neurovascular structures and postoperative intra-alveolar hematoma or edema after dental procedures. This results in paresthesia in the ipsilateral chin, lip (vermilion border, skin, and mucosa), and labial or buccal alveolar mucosa of the mandibular anterior teeth. However, there are no reports of sensory alterations in the teeth, especially tooth hypersensitivity, after IAN injury. I report a case in which paresthesia of the lower lip and hypersensitivity of the lower anterior teeth occurred simultaneously after the removal of the third molar that was located close to the IAN. In addition, I discuss the reasons for the different sensory changes between the tooth and chin (skin) after nerve injury from a neurophysiological point of view. Since the dental pulp and periodontal apparatus are highly innervated by the inferior alveolar sensory neurons, it seems necessary to pay attention to the changes in tooth sensitivity if IAN injury occurs during dental procedures.

Clinical Differential Diagnosis between Nonodontogenic and Endodontic Radiolucent Lesions in Periapical Location: A Critical Review

In endodontics, accurate diagnoses are important for the selection of appropriate and successful therapy. Several nonendodontic entities in periapical location may resemble those of inflammatory endodontic origin and impact therapeutic approaches. The aim of this study was to review noninflammatory entities mimicking dentoalveolar abscesses or apical periodontitis and to discuss clinical and pathological features. In this review study, the authenticated search engine in PubMed (MEDLINE) database was used to find articles by using "Nonvital Pulp Dentoalveolar Abscess", "Nonvital Pulp And Apical Periodontitis", "Periapical Abscess", "Chronic Dentoalveolar Abscess", "Chronic Apical Periodontitis", "Periapical Granuloma", And "Radicular Cyst". Each of these predefined keywords were combined with the terms "Misdiagnosed", "Mimicking", "Masquerading", or "Simulating" to search for reported cases indexed from 1978 to 2020. All case reports fulfilling the selection criteria were reviewed to identify radiolucent nonendodontic periapical lesions focused on the questions: "Which pathological entities mimick radiolucent endodontic lesions in periapical location? Based on endodontic clinical parameters, what are the contrasting features?" Out of 426 articles, 111 were relevant to the subject, including a series of cases and case reports. Only well-documented English and recent papers were considered. A total of 30 noninflammatory entities appeared clinically as radiolucent endodontic lesion in periapical location. Lesions simulating chronic apical periodontitis represented 83.3% and dentoalveolar abscess 16.7%. Interestingly, primary malignancies and metastasis counted 43.3% and pain was a typical symptom. Swelling was a noncontributory clinical feature in distinguishing periapical lesions. Lack of pulp response was registered in 68.4% of nonedodontic lesions. A flowchart was generated to summarize clinicopathological aspects of radiolucent nonendodontic entities appearing as dentoalveolar abscesses or apical periodontitis In relation to clinical practice, it is very important for us to note that, a group of pathological entities may simulate radiolucencies of endodontic origin in periapical location, especially malignancies and non-inflammatory odontogenic lesions.

Antibiotics Are Recommended, for the Urgent Management of Pulpal- and Periapical-Related Dental Pain and Intraoral Swelling, Only When There Is Systematic Involvement

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION

Evidence-based clinical practice guideline on antibiotic use for the urgent management of pulpal- and periapical-related dental pain and intraoral swelling: A report from the American Dental Association. Lockhart PB, Tampi MP, Abt E, et al. J Am Dent Assoc 2019;150(11):906-921.e12.

SOURCE OF FUNDING

The American Dental Association.

TYPE OF STUDY/DESIGN

Systematic review with meta-analysis of data.

"Comparative study of conventional anesthesia technique versus computerized system anesthesia: a randomized clinical trial"

OBJECTIVE

The aim of the present study was to compare in terms of pain perception the use of conventional anesthesia and a computerized system.

MATERIALS AND METHODS

Forty patients in need for extractions, dental restorative, or periodontal treatment bilaterally, were selected. Each patient served as his/her own control being subjected to two anesthesia techniques: conventional and electronically controlled anesthesia with Calaject® (Rønvig Dental MFG, Daugaard, Denmark). Each patient received both treatments in a blind way 1 week apart. The order was previously randomized. After performing the anesthesia (upper dental nerve, palatal posterior nerve, or inferior alveolar nerve), the patients evaluated their pain sensation with a visual analogue scale (VAS) (0-10). After treatment, the patients were asked about the presence of pain during the procedure. Finally, the patients selected their preference between the conventional and electronic anesthesia technique. Differences in assessment of pain's injection were analyzed using the Wilcoxon test and the Kruskal-Wallis test (α = 0.05).

RESULTS

The mean general pain experienced was 3.73 (1.55 SD) for the conventional anesthesia, and 1.95 (0.53 SD) for computerized anesthesia. Statistical differences (p < 0.05) were found. There was no difference between the treatments (p value = 0.061). Most patients did not feel any pain during the treatment. Finally, 92.5% of the patients preferred the electronic system.

CONCLUSIONS

Computerized anesthesia system produces significantly less pain compared with a conventional anesthesia syringe. Although both obtained sufficient anesthetic depth to perform treatments, the majority of patients chose electronic anesthesia as the most satisfactory.

CLINICAL RELEVANCE

Computerized anesthesia devices are valid and more comfortable alternative to conventional anesthesia.

Central mechanisms of pain in orofacial pain patients: Implications for management

BACKGROUND

Central sensitization (CS) is a form of neuroplasticity characterized by changes in the neural sensitivity, responsiveness, and/or output that are not contingent on peripheral input nor activity-dependent. CS is characterized by activation of unmyelinated C-fibers resulting in a cascade of events at molecular and cellular levels which eventuate into generation of synaptic currents at rest. CS, therefore, contributes to heightened generalized pain sensitivity, further complicates the process of reaching a diagnosis, and increases the possibility of treatment failure. BODY: Trigeminal nerve is the main sensory supplier of the anterior part of the head, including the intraoral structures. Primary afferent nociceptors of the trigeminal nerve and low threshold mechanoreceptors synapse with wide dynamic range (WDR) neurons in the pons. This multifaceted network of nerve interactions which is further complicated by the modulatory circuits that can suppress or heighten the activity of WDR neurons is one of the main contributors to CS. The importance of CS in orofacial pain disorders is emphasized in the context of chronic pain development. As for all chronic pain conditions, it is crucial to consider the biopsychosocial aspects of chronic orofacial pain in managing this diverse group of conditions. This review highlights current understanding of the biopsychosocial model and central mechanisms contributing to the pathogenesis of chronic orofacial pain.

Orofacial quantitative sensory testing: Current evidence and future perspectives

Background and objective

Orofacial quantitative sensory testing (QST) is an increasingly valuable psychophysical tool for evaluating neurosensory disorders of the orofacial region. Here, we aimed to evaluate the current evidence regarding this testing method and to discuss its future clinical potential.

Data treatment

We conducted a literature search in Medline, Embase and Scopus for English‐language articles published between 1990 and 2019. The utilized search terms included QST, quantitative, sensory testing and neurosensory, which were combined using the AND operator with the terms facial, orofacial, trigeminal, intraoral and oral.

Results

Our findings highlighted many methods for conducting QST—including method of levels, method of limits and mapping. Potential stimuli also vary, and can include mechanical or thermal stimulation, vibration or pinprick stimuli. Orofacial QST may be helpful in revealing disease pathways and can be used for patient stratification to validate the use of neurosensory profile‐specific treatment options. QST is reportedly reliable in longitudinal studies and is thus a candidate for measuring changes over time. One disadvantage of QST is the substantial time required; however, further methodological refinements and the combination of partial aspects of the full QST battery with other tests and imaging methods should result in improvement.

Conclusions

Overall, orofacial QST is a reliable testing method for diagnosing pathological neurosensory conditions and assessing normal neurosensory function. Despite the remaining challenges that hinder the use of QST for everyday clinical decisions and clinical trials, we expect that future improvements will allow its implementation in routine practice.

Applications of sensory and physiological measurement in oral-facial dental pain

Dentists regularly employ a variety of self‐report and sensory techniques to aid in the diagnosis and treatment of tooth‐related disease. Many of these techniques leverage principles borrowed from psychophysics, the quantitative measurement of the relationship between stimuli and evoked sensations, which falls under the larger umbrella of quantitative sensory testing (QST). However, most clinicians fail to meet the bar for what could be considered quantitative sensory testing, and instead focus on qualitative and dichotomous “yes/no” aspects of sensory experience. With our current subjective measurements for pain assessments, diagnosis and treatment of dental pain in young children and individuals (any age) with severe cognitive impairment rely extensively on third‐party observations. Consequently, the limitation of inadequate pain diagnosis can lead to poor pain management. In this review, it discusses mechanisms that underlie acute and chronic dental pain. It details the measurement of somatosensory responses and pulpal blood flow as objective measures of tooth health and pain. It proposes that bridging these varied methodologies will significantly improve diagnosis and treatment of orofacial pain and pathology. It concludes that improving the precision of sensory measurements could yield important improvements in diagnostic challenges in pulpal pathology for noncommunicative and cognitively impaired individuals.