Orofacial pain: a guide for the headache physician

Incidence, diagnosis, and management of orofacial pain among new patients receiving tertiary care in Thailand: A 6-year retrospective study comparing before and during the COVID-19 outbreak

BACKGROUND

There is insufficient data on orofacial pain related to the COVID-19 outbreak in Thailand.

OBJECTIVE

To investigate the incidence, diagnosis and management of orofacial pain among new patients over the last 6 years, before and during the COVID-19 outbreak.

METHODS

Medical records from new patients who first visited Chulalongkorn Dental Hospital between 2017 and 2022 were retrospectively investigated. The sample size was determined, and proportional stratified random sampling was employed to distribute the sample number proportionally across each year. The hospital number of each patient was randomised using online software as a sampling strategy. A data collection form was developed and used to gather information from the digital data system.

RESULTS

At the first visit, 770 out of 1359 patients (56.7/100 people, 95% CI: 54.0-59.3) reported orofacial pain defined as acute, chronic and unclassified pain. The most common chief complaints based on the AAOP classification were odontogenic pain (90.00%) and temporomandibular disorders (6.10%). The top three provisional modified ICD-10-TM diagnoses among these patients were pulp diseases (21.95%), impacted teeth (20.65%) and dental caries (9.09%). 81.87% of dental students' provisional diagnoses matched the final diagnoses given by dental specialists. Only 63.38% of orofacial pain patients were completely managed during the COVID-19 pandemic with common procedures being surgical removal, extraction and root canal therapy.

CONCLUSION

Half of Thai dental patients seeking tertiary care at a university dental hospital reported orofacial pain, which was not impacted by the COVID-19 pandemic. In contrast, dysfunction-related problems in the orofacial area significantly increased during the pandemic.

Microglia cause structural remodeling of noradrenergic axon in the trigeminal spinal subnucleus caudalis after infraorbital nerve injury in rats

The dysfunction of descending noradrenergic (NAergic) modulation in second-order neurons has long been observed in neuropathic pain. In clinical practice, antidepressants that increase noradrenaline levels in the synaptic cleft are used as first-line agents, although adequate analgesia has not been occasionally achieved. One of the hallmarks of neuropathic pain in the orofacial regions is microglial abnormalities in the trigeminal spinal subnucleus caudalis (Vc). However, until now, the direct interaction between descending NAergic system and Vc microglia in orofacial neuropathic pain has not been explored. We found that reactive microglia ingested the dopamine-β-hydroxylase (DβH)-positive fraction, NAergic fibers, in the Vc after infraorbital nerve injury (IONI). Major histocompatibility complex class I (MHC-I) was upregulated in Vc microglia after IONI. Interferon-γ (IFNγ) was de novo induced in trigeminal ganglion (TG) neurons following IONI, especially in C-fiber neurons, which conveyed to the central terminal of TG neurons. Gene silencing of IFNγ in the TG reduced MHC-I expression in the Vc after IONI. Intracisternal administration of exosomes from IFNγ-stimulated microglia elicited mechanical allodynia and a decrease in DβH in the Vc, which did not occur when exosomal MHC-I was knocked down. Similarly, in vivo MHC-I knockdown in Vc microglia attenuated the development of mechanical allodynia and a decrease in DβH in the Vc after IONI. These results show that microglia-derived MHC-I causes a decrease in NAergic fibers, culminating in orofacial neuropathic pain.

Astrocytic and microglial interleukin-1β mediates complement C1q-triggered orofacial mechanical allodynia

Glial cells, such as microglia and astrocytes, in the trigeminal spinal subnucleus caudalis (Vc) are activated after trigeminal nerve injury and interact with Vc neurons to contribute to orofacial neuropathic pain. Complement C1q released from microglia has been reported to activate astrocytes and causes orofacial mechanical allodynia. However, how C1q-induced phenotypic alterations in Vc astrocytes are involved in orofacial pain remains to be elucidated. Intracisternal administration of C1q caused mechanical allodynia in the whisker pad skin and concurrent significant upregulation of glial fibrillary acidic protein and ionized calcium-binding adapter molecule 1 in the Vc. Immunohistochemical analyses clarified that C1q induces a significant increase in the cytokine interleukin (IL)-1β, predominantly in Vc astrocytes and partially in Vc microglia. The number of c-Fos-positive neurons in the Vc increased significantly in response to C1q. IL-1 receptor antagonist (IL-1Ra) was used to analyze the involvement of IL-1β in C1q-induced mechanical allodynia. Intracisternal administration of IL-1Ra ameliorated C1q-induced orofacial mechanical allodynia. The present findings suggest that IL-1β released from activated astrocytes and microglia in the Vc mediates C1q-induced orofacial pain.

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.

Myrtenol Reduces Orofacial Nociception and Inflammation in Mice Through p38-MAPK and Cytokine Inhibition

Orofacial pain is one of the commonest and most complex complaints in dentistry, greatly impairing life quality. Preclinical studies using monoterpenes have shown pharmacological potential to treat painful conditions, but the reports of the effects of myrtenol on orofacial pain and inflammation are scarce. The aim of this study was to evaluate the effect of myrtenol in experimental models of orofacial pain and inflammation. Orofacial nociceptive behavior and the immunoreactivity of the phosphorylated p38 (P-p38)-MAPK in trigeminal ganglia (TG) and spinal trigeminal subnucleus caudalis (STSC) were determined after the injection of formalin in the upper lip of male Swiss mice pretreated with myrtenol (12.5 and 25 mg/kg, i.p.) or vehicle. Orofacial inflammation was induced by the injection of carrageenan (CGN) in the masseter muscle of mice pretreated with myrtenol (25 and 50 mg/kg, i.p.) or its vehicle (0.02% Tween 80 in saline). Myeloperoxidase (MPO) activity and histopathological changes in the masseter muscle and interleukin (IL)-1β levels in the TG and STSC were measured. The increase in face-rubbing behavior time induced by formalin and P-p38-MAPK immunostaining in trigeminal ganglia were significantly reduced by myrtenol treatment (12.5 and 25 mg/kg). Likewise, increased MPO activity and inflammatory histological scores in masseter muscle, as well as augmented levels of IL-1β in the TG AND STSC, observed after CGN injection, were significantly decreased by myrtenol (25 and 50 mg/kg). Myrtenol has potential to treat orofacial inflammation and pain, which is partially related to IL-1β levels in the trigeminal pathway and p38-MAPK modulation in trigeminal ganglia.

A 10-year overview of chronic orofacial pain in patients at an oral medicine center in Iran

Background

Orofacial pain is defined as pain felt in the soft or hard tissues of the head, face, mouth, and neck. Chronic orofacial pain is often challenging to diagnose and difficult to treat. Due to the lack of available information about the prevalence and clinical form of orofacial pain, this study aimed to evaluate the characteristics of chronic orofacial pain in patients presenting at the Department of Oral Medicine of Shahid Beheshti Dental School between 2012 and 2022.

Methods

In this retrospective study, we evaluated the files of 121 patients at the Department of Oral and Maxillofacial Diseases of Shahid Beheshti Dental School, which were completed during 2012–2022. We extracted the required information from these files.

Results

In total, 121 files were included in the study (30 male, 91 female). The mean age of the patients was 43.68 ± 16.79 years. The most common diagnosis in patients with chronic orofacial pain was temporomandibular disorders (TMD) (55.3%). Among pain-related factors, psychological factors showed the highest frequency (30.5%). Opening and closing (43.8%) had the highest frequency among factors that increased pain, and the rest (6.6%) had the highest frequency among the factors that reduced pain. Most patients experienced unilateral pain over the masseter area. Most patients reported their pain intensity to be greater than 7 in the verbal analog scale (VAS). The most common symptom associated with pain was joint noise (37.1%).

Conclusion

A ten-year retrospective evaluation of patient files showed that more than half of the patients with chronic orofacial pain had TMD.

Ultrasound is Effective to Treat Temporomandibular Joint Disorder

Background

Temporomandibular joint disorder (TMD) affects millions of people. It is unclear if low intensity ultrasound (US) is effective to treat TMD.

Methods

A total of 160 patients with TMD were enrolled in this study. The subjects were randomized into two groups to receive US therapy or no therapy. Patients in the US group were given US therapy once a day for 5 days per week for 2 consecutive weeks. Before and 4 weeks and 6 months after the treatments, the patients were assessed for pain using visual analog scale (VAS) and the maximum pain-free inter-incisal distance (IID). In addition, mandibular movement (MM), jaw noise (JN), disability index (DI) and craniomandibular index (CMI) were also assessed.

Results

Compared with the patients before the therapy, VAS, IID, MM, JN, DI and CMI in the US group were significantly improved 4 weeks and 6 months after therapy. However, 6 months after the therapy, US group had a recurrence rate of 2.63%.

Conclusion

US therapy can significantly reduce the pain, and improve the functionality of the temporomandibular joint and mouth opening limit for TMD patients, and is therefore recommended for TMD patients.

Telemedicine for a Multidisciplinary Assessment of Orofacial Pain in a Patient Affected by Eagle’s Syndrome: A Clinical Case Report

Background:

Orofacial pain has a broad range of origins and a multidisciplinary approach occupies a relevant role.

Objective:

The aim of this study was to review the literature regarding the evolution of telemedicine and orofacial pain related to a case report of a patient affected by Eagle's syndrome.

Materials and Methods:

Two authors (RJM and SG) independently reviewed the literature up to March 2020. A case report was developed by including the interdisciplinary assessment and initial treatment of orofacial pain in a 38-year-old female patient affected by Eagle’s syndrome. The patient was interviewed by two different specialists (from Rome, Italy and Los Angeles, California) through an online meeting platform in order to evaluate her complex situation, demonstrating the possibilities that telemedicine offered during the COVID-19 pandemic.

Conclusion:

An interdisciplinary approach can be performed for future follow ups on patients as various advantages were found by the patient and by the clinicians themselves.

"Tomorrow, I'll Be Fine": Impacts and coping mechanisms in adolescents and young adults with primary dysmenorrhoea

AIMS

To understand the experiences of adolescents and young adults with primary dysmenorrhoea through the lens of structured frameworks extant in contemporary pain literature.

DESIGN

Descriptive qualitative study.

METHODS

Thirty-nine adolescents and young adults (ages 16-24 years) with primary dysmenorrhoea participated in semi-structured in-person interviews. Transcripts of the interviews were analysed using deductive thematic analysis from November 2018 to April 2019.

RESULTS

Two overarching themes, each with subthemes, were identified. The first theme, primary dysmenorrhoea impacts the whole person, contained the following subthemes: biological, social, and psychological. The second theme, coping mechanisms of women with primary dysmenorrhoea, contained the following subthemes: primary, secondary, and passive coping.

CONCLUSION

Women experience several primary dysmenorrhoea-related impacts on their biological, social, and psychological functioning. Women employ a variety of coping mechanisms to manage their primary dysmenorrhoea pain.

IMPACT

This study emphasizes the significant effects of primary dysmenorrhoea on nearly every aspect of women's lives and contributes to an understanding of the ways women cope with this pain. The findings of this study underscore the need for continued consideration of primary dysmenorrhoea as a debilitating pain process as well as the need for additional interventions to help women manage this condition.

Natural products for orofacial nociception in pre-clinical studies: A systematic review

OBJECTIVE

The aim of this systematic review was to summarize the use of natural products (NP) in the treatment of orofacial nociception in animal models.

METHODS

Pre-clinical studies that have evaluated the efficacy of NPs in experimental orofacial nociception were sought in the Medline, Web of Science, Scopus, Embase, SciELO, LILACS and Scholar databases in January 2020, covering the period since the inception of each one. Two reviewers independently selected the studies, extracted the data and evaluated the risk of bias of the included studies.

RESULTS

We included 41 records in qualitative synthesis. Fifty different NPs were investigated. All studies presented positive results for at least one orofacial nociception test. Regarding the risk of bias, most studies presented poor experimental design, mainly lack of randomization and blinding. The main class of isolated compounds tested was terpenes, of which monoterpenes were investigated in the majority of the studies.

CONCLUSION

These results indicate that NPs are effective in treating experimental orofacial nociception and highlight some of these NPs, mainly terpenes, suggesting their potential for translational research.

Temporal tendinosis: A cause of chronic orofacial pain

PURPOSE OF REVIEW

Diverse musculoskeletal disorders and neuropathic symptoms of the face pose significant diagnostic challenges. In particular, temporal tendinosis is generally overlooked in the medical and dental literature and is therefore a poorly understood topic and often problematic cause of chronic orofacial pain. In this article, we explore temporal tendinosis as a cause of unresolved orofacial pain by reviewing the complex anatomy of the temporalis muscle, common presentations of temporal tendinosis, possible etiologies for injury and place a strong emphasis on required diagnostic evaluation and clinical management.

RECENT FINDINGS

Temporal tendinosis remains under diagnosed due to a combination of anatomical complexity and incomplete description in the majority of general anatomy medical textbooks. The two main presentations are unilateral facial pain with or without temporal headache and pain radiating from the distal temporalis tendon to the temporalis muscle. Diagnosis should be made with a combination of focused history, physical examination and specialised imaging, preferably with ultrasound but with MRI an alternate option. While many management options are available, optimal treatment remains unclear. Temporal tendinosis is an under-recognised and under-treated condition. Despite the fact that orofacial pain is one of the single most common complaints of patients presenting to physicians or dentists, it is widely acknowledged that training for diagnosis and manage of temporal tendinopathy among primary care physicians in both medical and dental professions is inadequate. This may result in extensive workups, leading to suboptimal management and chronic pain syndromes.

Orofacial pain of cervical origin: A case report

BACKGROUND

The etiopathogenesis of orofacial pain remains complex and a number of pain referral patterns for this region have been reported in the literature. The purpose of this report is to describe the assessment and successful clinical management of orofacial pain possibly attributable to cervical origin.

CASE DESCRIPTION

A 55-year-old male teacher with a 3-year history of pain in the right lower jaw, radiating to the ear, consulted our institute for assessment and management. The patient was unsuccessfully treated for dental pain and trigeminal neuralgia. The patient's functioning was grossly limited and the patient was unable to sleep because of severe pain. Current and previous medical and physical examinations revealed no infection, malignancies, or sinusitis. Palpation revealed no temporomandibular disorder, tenderness or myofascial trigger points. Examination of the cervical range of motion showed a reduction in rotation to the right side. The patient was treated for upper cervical joint dysfunction involving mobilization of the first three cervical vertebrae and motor control exercises. The patient had an almost complete resolution of symptoms and reported significant improvement in the Patient Specific Functional Scale (PSFS) and the Global Rating of Change (GRC) scale.

CONCLUSION

This case study demonstrates the importance of considering, assessing and treating the cervical spine as a possible source of orofacial pain, and the positive role of cervical mobilization on these disorders.

Evaluation and management of orofacial pain

Challenging to diagnose and manage, orofacial pain is a common and costly problem with a profound effect on quality of life. Delayed diagnosis and management can lead to prolonged patient suffering and disability. This article describes the background, assessment, differential diagnosis, management, and referral of patients with orofacial pain.

Assessing and treating primary headaches and cranio-facial pain in patients undergoing rehabilitation for neurological diseases

BACKGROUND

Pain is a very common condition in patient undergoing rehabilitation for neurological disease; however the presence of primary headaches and other cranio-facial pains, particularly when they are actually or apparently independent from the disability for which patient is undergoing rehabilitation, is often neglected. Diagnostic and therapeutic international and national guidelines, as well as tools for the subjective measure of head pain are available and should also be applied in the neurorehabilitation setting. This calls for searching the presence of head pain, independently from the rehabilitation needs, since pain, either episodic or chronic, interferes with patient performance by affecting physical and emotional status. Pain may also interfere with sleep and therefore hamper recovery.

METHODS

In our role of task force of the Italian Consensus Conference on Pain in Neurorehabilitation (ICCPN), we have elaborated specific recommendations for diagnosing and treating head pains in patients undergoing rehabilitation for neurological diseases.

RESULTS AND CONCLUSION

In this narrative review, we describe the available literature that has been evaluated in order to define the recommendations and outline the needs of epidemiological studies concerning headache and other cranio-facial pain in neurorehabilitation.

Side-locked headaches: an algorithm-based approach

The differential diagnosis of strictly unilateral hemicranial pain includes a large number of primary and secondary headaches and cranial neuropathies. It may arise from both intracranial and extracranial structures such as cranium, neck, vessels, eyes, ears, nose, sinuses, teeth, mouth, and the other facial or cervical structure. Available data suggest that about two-third patients with side-locked headache visiting neurology or headache clinics have primary headaches. Other one-third will have either secondary headaches or neuralgias. Many of these hemicranial pain syndromes have overlapping presentations. Primary headache disorders may spread to involve the face and / or neck. Even various intracranial and extracranial pathologies may have similar overlapping presentations. Patients may present to a variety of clinicians, including headache experts, dentists, otolaryngologists, ophthalmologist, psychiatrists, and physiotherapists. Unfortunately, there is not uniform approach for such patients and diagnostic ambiguity is frequently encountered in clinical practice.

Herein, we review the differential diagnoses of side-locked headaches and provide an algorithm based approach for patients presenting with side-locked headaches. Side-locked headache is itself a red flag. So, the first priority should be to rule out secondary headaches. A comprehensive history and thorough examinations will help one to formulate an algorithm to rule out or confirm secondary side-locked headaches. The diagnoses of most secondary side-locked headaches are largely investigations dependent. Therefore, each suspected secondary headache should be subjected for appropriate investigations or referral. The diagnostic approach of primary side-locked headache starts once one rule out all the possible secondary headaches. We have discussed an algorithmic approach for both secondary and primary side-locked headaches.

The impact of chronic orofacial pain on daily life: the vulnerable patient and disruptive pain

OBJECTIVE

To identify patient and pain characteristics associated with negative impacts on daily life among patients with chronic orofacial pain (COFP).

STUDY DESIGN

Medical records of 200 COFP patients were analyzed.

RESULTS

Diagnostic categories included temporomandibular disorders (85; 42.7%), headaches (47; 23.6%), neuropathic pain (37; 18.5%), trigeminal neuralgia (16; 8.0%), and painful posttraumatic trigeminal neuropathy (PTTN) (14; 7.0%). Of these, 47 (23.7%) had medical and 13 (6.5%) had psychiatric comorbidities and 71 (35.7%) experienced physical trauma. Seven (5%) had stopped working, and mean days absent from work was 3.3 ± 19.3. Patients were previously treated by 2.7 ± 1.4 caregivers. Mean scores on a 0-10 scale were as follows: pain (7.13 ± 2.3), sleep quality (6.6 ± 2.4), and quality of life (5.58 ± 3.1). PTTN patients were more likely to quit work (P = .009) and had more days absent from work (mean 24.3; P = .009). We identified patient and pain profiles that predict these poor outcomes. The "vulnerable patient" profile includes health and psychiatric comorbidities and trauma history, particularly PTTN. The "disruptive pain" profile includes severe, continuous, burning, electrical pain accompanied by systemic signs. These profiles intersect in a complex manner, creating a complex feedback loop.

CONCLUSIONS

A multidisciplinary team approach is recommended to manage COFP patients, in order to improve treatment outcomes and avert more serious consequences.

What should we tell patients with painful temporomandibular disorders about what to eat?

BACKGROUND AND OVERVIEW

Patients with painful temporomandibular disorders (TMD) commonly report problems eating, owing to limited mandibular opening and pain and discomfort with biting and chewing. Consequently, painful TMD may affect dietary intake and nutritional status.

CONCLUSIONS

Treatment of painful TMD is multifaceted and involves pharmacologic, physical, and cognitive behavior and dietary therapies. Painful TMD may influence the quality of dietary intake and eating behaviors. There is a dearth of established guidelines and validated measures that clinicians can use to assess and manage diet and nutritional well-being in patients with this disorder. The authors present recommendations in an effort to guide clinicians on how to help patients with painful TMD improve the quality of their diets and avoid or minimize eating-related pain.

PRACTICAL IMPLICATIONS

Providing comprehensive care for patients with painful TMD should include diet evaluation and recommendations for eating comfortably and supporting nutrition. An interprofessional approach may help improve treatment outcomes. Research is needed to develop evidence-based guidelines for diet and nutrition that clinicians can use in the care of patients with painful TMD.

The status of temporomandibular and cervical spine education in credentialed orthopedic manual physical therapy fellowship programs: a comparison of didactic and clinical education exposure

OBJECTIVE

The purpose of this investigation was to establish a baseline of physical therapist education on temporomandibular disorders (TMD)-related topics during credentialed orthopedic manual physical therapy fellowship training and compare it to cervical spine disorders education.

METHOD

An online survey was distributed electronically to each fellowship program credentialed by the American Physical Therapy Association (APTA) and recognized by the Academy of Orthopedic Manual Physical Therapists (AAOMPT). Data were analyzed to compare overall exposure to TMD educational content, including a direct comparison of TMD and cervical spine disorders education.

RESULTS

The response rate was 79%. Thirteen programs (87%) reported providing both didactic and clinical training on both TMD and cervical spine disorders. Didactic education for cervical spine disorders ranged from 16-20 hours to over 25 hours, whereas TMD hours ranged from 0 to 6-10 hours. Clinical education for cervical spine disorders ranged from 11-15 hours to over 25 hours, whereas TMD hours ranged from 0 to 6-10 hours. The number of hours of exposure during didactic training and the number of patients exposed to during clinical training were significantly different when comparing TMD to cervical spine disorders exposure (P<0.0001).

DISCUSSION

The data indicate a lack of uniformity between credentialed fellowship programs in orthopedic manual physical therapy with respect to the extent to which programs expose trainees to evaluation and management of TMD. There is consistency in that all programs provided more training on cervical spine disorders than TMD. Despite a high level of clinical specialization, fellows-in-training receive minimal TMD education.