Translational research of temporomandibular joint pathology: a preliminary biomarker and fMRI study

Assessment of cephalometric parameters and correlation with the severity of the obstructive sleep apnea syndrome

BACKGROUND

In individuals diagnosed with obstructive sleep apnea syndrome (OSAS), variations in craniofacial structure have been inconsistently documented, showing differing degrees of alteration between obese and nonobese patients. In addition, sleep disturbance has also been shown to induce disequilibrium in this population of patients. This pilot observational study aimed to assess craniofacial values in obese and nonobese subpopulations of patients with OSAS and their correlation and association with the severity of OSAS. We also assessed whether OSAS patients are characterized by an impaired equilibrium in relation to and associated with the severity of OSAS.

METHODS

We included all consecutive adult patients with OSAS. Through cephalometry, we assessed the upper (UPa-UPp) and lower (LPa-LPp) pharynx diameters, superior anterior facial height (Sor-ANS), anterior facial height (ANS-Me), anterior vertical dimension (Sor-Me), posterior facial height (S-Go) and craniovertebral angle (CVA). Furthermore, we analyzed postural equilibrium through a stabilometric examination.

RESULTS

Forty consecutive OSAS patients (45% female with a mean age of 56 ± 8.2 years) were included. The subgroup of nonobese patients had a reduced UPa-UPp (p = 0.02). Cephalometric measurements were correlated with the severity of OSAS in nonobese patients, whereas only Sor-ANS was correlated with the severity of OSAS in the obese subpopulation. In the overall population, altered craniofacial values are associated with severe OSAS. Although there are differences in equilibrium between obese and nonobese OSAS patients, the stabilometric measurements were not correlated or associated with OSAS severity.

CONCLUSION

Altered craniofacial values and compromised equilibrium in OSAS patients are linked to OSAS severity. Therefore, the management of OSAS should be tailored not only to weight management but also to craniofacial and postural rehabilitation to enhance patient outcomes.

Myofascial Temporomandibular Disorders at a Turning Point: Pragmatic or Evidence-Based Management?

Unvalidated theories have been proposed for the etiopathogenesis of masticatory myofascial temporomandibular disorders (mTMD). Modalities such as cone-beam computed tomography/computed tomography and MRI contributes little to the diagnosis of mTMD. Diagnosing mTMD is based on the recognition of "familiar pain" presentation in the masticatory myofascial tissue. This assessment tool contributes little our understanding of the underlying disease process. Thus, management of mTMD is empirical and arbitrary. Exploring emerging technologies to identify biomarkers and objectively assess myofascial tissue physiology in disease and health may be key in moving the diagnosis of mTMD from the pragmatic paradigm to an evidence-based paradigm.

Temporomandibular Joint Imaging

Prescriptions for imaging studies for temporomandibular disorders are based on the patient's complaint, history, and clinical findings. Appropriate selection criteria and justification for imaging examinations must be followed. Because the temporomandibular joint is composed of both hard and soft tissues, different studies are prescribed based on the clinically suspected condition. Current imaging modalities include panoramic radiographs, cone-beam computed tomography, and MRI. The entire examination must be interpreted, and the findings recorded in the patient record. No one imaging modalities is suitable for all patients. An oral and maxillofacial radiologist should be consulted when the interpretation of the study is beyond the scope of the practitioner.

Effects of occlusal splint and exercise therapy, respectively, for the painful temporomandibular disorder in patients seeking for orthodontic treatment: a retrospective study

OBJECTIVE

To evaluate the effect of hard stabilization splints (HSS), counselling and exercise therapies, respectively, for the painful temporomandibular disorder (TMD) in patients seeking for orthodontic treatment through magnetic resonance imaging (MRI) and clinical examination.

MATERIALS AND METHODS

Eighty-seven TMD patients were divided into two groups according to their therapies: the HSS group (n = 43) comprising of patients treated with HSS, counselling and masticatory muscle exercises; the control group (n = 44) comprising of patients treated with counselling and masticatory muscle exercises alone. All patients had orthodontic therapies after the first treatment phase. The joint pain and clicking of all patients were recorded via clinical examination. MRIs of HSS groups were taken before (T₀), after the first phase (T₁), and after the orthodontic treatment (T₂). Parameters indicating the condyles and articular discs were evaluated. Clinical symptom (pain and clicking) changes among T₀, T₁ and T₂ time point were detected in the two groups respectively. The significant differences between HSS and control groups, as well as between male and female were tested at T₁ and T₂. Position changes of condyles and discs in HSS group among T₀, T₁ and T₂ were detected in male and female respectively.

RESULTS

After the first treatment phase, there was no difference in the decrease of facial pain between the two group, as well as between male and female in the two groups (P > 0.05). Clicking decreasing was not statistically significant. After the whole orthodontic periods, the TMJ pain relapsed in female of the control group, and the number of female's pain joints was more than male's (P < 0.05). In the HSS group, the posterosuperior movements of discs and the anteroposterior movements of condyles were recorded in closing position (P < 0.05). After the whole orthodontic periods, female's disc-condyle angles increased, the discs to HRP distance decreased and condyles to VRP distance increased when compared with the data of T₁ (P < 0.05).

CONCLUSIONS

For the orthodontic patients with painful TMD, HSS combined with counselling and exercise therapies before orthodontic treatment could provide pain relief. HSS is helpful to improve the position and relation of discs and condyles. In addition, male's prognosis is better than female's in terms of stability.

Determination of pain intensity, pain-related disability, anxiety, depression, and perceived stress in Polish adults with temporomandibular disorders: A prospective cohort study

BACKGROUND

There is a need to assess a relationship between the psychoemotional state of patients and the occurrence and the intensity of pain and temporomandibular disorders (TMD) in relation to a Polish population. There are no such precision data in the literature relating to the population of big Eastern European country. The study conducted by the authors refer to a large group of male and female adult patients of the Polish population in a different age profile. As a result, this study provides a picture of the situation that also takes into account population characteristics that may affect the clinical situation of patients.

OBJECTIVE

The aim of the study was to assess the pain intensity, pain-related disability, anxiety, depression, and perceived stress among Polish adults with TMD as well as the association between psychosocial impairment and TMD.

MATERIALS AND METHODS

This prospective cohort study included 219 adult patients from the Outpatient Clinic for Temporomandibular Disorders at the Academic Dental Polyclinic in Wroclaw. The patients completed validated questionnaires, and received a TMD diagnosis based on a standardized examination (Diagnostic Criteria for Temporomandibular Disorders) performed by a qualified dentist. A statistical analysis was carried out on the collected data.

RESULTS

Myalgia was the most commonly diagnosed condition among the TMD patients. Furthermore, the prevalence of perceived stress, anxiety, and depression was high in the studied sample. Females showed more depression symptoms than males, while the level of anxiety and stress was similar in both groups. The most statistically significant correlation was observed between the group of masticatory muscle disorders and the level of depression, stress, pain intensity, and pain-related disability.

CONCLUSION

Due to the high prevalence of increased levels of anxiety, depression, and perceived stress, it is essential to screen the psychosocial status of Polish TMD adult patients. Psychosocial status may have an impact on a studied patient's response to treatment and pain intensity, and pain-related disability. Therefore, Polish TMD adult patients should be provided with management based on an interdisciplinary approach.

CLINICAL TRIAL REGISTRATION

[https://clinicaltrials.gov/], identifier [NCT05183503].

Preclinical models of deep craniofacial nociception and temporomandibular disorder pain

Chronic pain in temporomandibular disorder (TMD) is a common health problem. Cumulating evidence indicates that the etiology of TMD pain is complex with multifactorial experience that could hamper the developments of treatments. Preclinical research is a resource to understand the mechanism for TMD pain, whereas limitations are present as a disease-specific model. It is difficult to incorporate multiple risk factors associated with the etiology that could increase pain responses into a single animal. This article introduces several rodent models which are often employed in the preclinical studies and discusses their validities for TMD pain after the elucidations of the neural mechanisms based on the clinical reports. First, rodent models were classified into two groups with or without inflammation in the deep craniofacial tissues. Next, the characteristics of each model and the procedures to identify deep craniofacial pain were discussed. Emphasis was directed on the findings of the effects of chronic psychological stress, a major risk factor for chronic pain, on the deep craniofacial nociception. Preclinical models have provided clinically relevant information, which could contribute to better understand the basis for TMD pain, while efforts are still required to bridge the gap between animal and human studies.

Cortical representation of experimental periodontal pain: a functional magnetic resonance imaging study

The aim of this study was to investigate central pain representations during loading of the periodontium induced by orthodontic and occlusal stress. Nineteen healthy male volunteers (25.7 ± 2.8 years) were tested on two consecutive days: after phenotyping (questionnaires) and determination of warmth (WPT) and heat (HPT) pain thresholds, functional magnetic resonance imaging was performed as event-related paradigm including 36 tooth clenchings of 3 s duration, alternating with rest periods varying between 20–30 s. The task was performed in absence (T1) and 24 h after placement of an elastic separator between the second bicuspid and the first molar on the right side of the lower jaw (T2). No significant changes in WPT and HPT were observed but pain ratings were significantly elevated at T2. Significantly elevated activation at T2, as compared to T1, was found in bilateral sensorimotor cortex, bilateral secondary sensory cortex, supplementary motor area, right rolandic operculum, and bilateral insula. Our data show for the first time in humans that periodontal stimulation, as tested by tooth clenching in the presence of an elastic separator, goes along with specific expressions of pain at behavioral and neuronal network levels. Findings supplement the existing neuroimaging literature on odontogenic pain.

Sinus, disabling tension-type, and temporomandibular joint headaches

PURPOSE OF REVIEW

Clinicians frequently face questions from headache patients regarding the roles played by sinus issues, muscle tension, and temporomandibular joint (TMJ) problems. This review highlights new concepts regarding the diagnosis and management of these headache conditions and their differentiation from migraine.

RECENT FINDINGS

Recent research has clarified the roles played by pathology in the paranasal sinuses and TMJ in patients reporting headache. Additional information from physiologic studies in patients with tension-type headache (TTH) has improved the understanding of this condition.

SUMMARY

Improved understanding of sinus headache, disabling TTH, and TMJ headache and their differentiation from migraine will lead to reductions in unnecessary diagnostic procedures and unwarranted medical and surgical procedures. More expedient recognition of the origin of headache should lead to improved therapeutic outcomes.

Evolution patterns of SARS-CoV-2: Snapshot on its genome variants

An acute respiratory syndrome (COVID-19), caused by a novel coronavirus (SARS-CoV-2) with a high rate of morbidity and elevate mortality, has emerged as one of the most important threats to humankind in the last centuries. Rigorous determination of SARS-CoV-2 infectivity is very difficult owing to the continuous evolution of the virus, with its single nucleotide polymorphism (SNP) variants and many lineages. However, it is urgently necessary to study the virus in depth, to understand the mechanism of its pathogenicity and virulence, and to develop effective therapeutic strategies. The present contribution summarizes in a succinct way the current knowledge on the evolutionary and structural features of the virus, with the aim of clarifying its mutational pattern and its possible role in the ongoing pandemic.

Imaging of the temporomandibular joint

Temporomandibular disorders are common, especially in young to middle-aged women, and most settle with supportive treatment. Imaging is indicated for the small percentage of cases that do not respond to conservative management and when the diagnosis is no doubt. The temporomandibular joint (TMJ) is a bilateral synovial articulation between the mandible and skull base. It has an intra-articular disc dividing the joint into superior and inferior compartments and the articular surfaces are lined with fibrocartilage. The normal imaging anatomy of the TMJ is described and illustrated. Different movements occur in each joint compartments: a hinge movement in the inferior joint space and translation or gliding in the superior joint space. Internal derangement is the commonest disorder affecting the TMJ and is most commonly due to disc displacement, followed by osteoarthritis and inflammatory arthritides. The imaging findings, primarily on magnetic resonance imaging (MRI) and computed tomography (CT), of internal derangement and less common disorders of the joint, are reviewed and illustrated. Optimal imaging protocols are discussed with detailed reporting guidelines.