Establishment of a temporomandibular physiological state with neuromuscular orthosis treatment affects reduction of TMD symptoms in 313 patients

Instrumental Occlusal Analysis in Migraine Patients: A Quantitative Cross Sectional Study

OBJECTIVES

This study aimed to investigate possible differences of functional occlusal variables between a group of migraine patients (MG) and a control group (CG).

MATERIALS AND METHODS

Each group included 50 individuals. Instrumental functional analysis and digital occlusal analysis were performed. Variables examined were condylar displacement from a reference position to maximum intercuspation; angular difference between the steepness of the articular eminence and the contra-lateral canine guidance; and angular difference between the steepness of the articular eminence and the ipsilateral central incisor guidance and occlusal plane inclination. Self-reported grinding and occlusal index were also investigated.

RESULTS

There were statistically significant differences in the extent of retral condylar displacement assessed both clinically [MG: 0.49 mm (SD 0.67 mm), CG: 0.29 mm (SD 0.27 mm), p = 0.012] and digital-mechanically [MG: 1.53 mm (SD 0.95 mm), CG: 0.9 mm (SD 0.66 mm), p = 0.001], the angular difference between the steepness of the articular eminence and the contra-lateral canine guidance [MG: 13.11° (SD 8.33°), CG: 9.47° (SD 7.08°), p = 0.021 and MG: 12.94° (SD 8.71°), CG: 9.44° (SD 8.70°), p = 0.017], and the occlusal plane inclination [MG: 11.16° (SD 4.66°), CG: 9.09° (SD 4.37°), p = 0.024]. Self-reported grinding (MG: 39/50, CG: 12/50, p < 0.001) and occlusal index [MG: 1.92 (SD 0.46), CG: 0.21 (SD 0.66), p < 0.001] were also significantly higher in migraineurs.

CONCLUSIONS

Articular and occlusal structures could play a role in migraine and thus should be considered in an interdisciplinary approach.

Effect of transcutaneous electrical nerve stimulation (TENS) on the electromyographic activity of human masticatory muscles in young people with normal occlusion

STATEMENT OF PROBLEM

Transcutaneous electrical nerve stimulation (TENS) has been used in several clinical areas. However, the effect of TENS on the masticatory muscles of young individuals with normal occlusion remains unclear.

PURPOSE

The purpose of the study was to assess the effect of TENS on the surface electromyographic (sEMG) activity of masticatory muscles in a young population with normal occlusion.

MATERIAL AND METHODS

Twenty residents (5 men and 15 women, mean 24.27 ±2.59 years) of Dalian Stomatological Hospital were enrolled as the study participants. A trained operator collected the required information from the participants. The experiment was divided into 3 stages: pre-TENS acquisition, TENS application, and post-TENS acquisition. The pre-TENS stage was performed using surface electromyography (sEMG) (Myotronics Inc) to acquire the potential values of masticatory muscles in the following 3 states 5 times each: resting, intercuspal occlusion (ICO), and maximum voluntary clench (clenching). The potential values of the anterior of temporalis (TA), the masseter (MM), the sternocleidomastoid (SCM), and the anterior digastric (DA) muscles were collected in the resting state, and TA and MM were collected in the ICO and clenching states. During the TENS application phase, a TENS Unit device (J5 Myomonitor) (J5) was used on each participant for 45 minutes. The post-TENS acquisition phase involved the same procedure as the pre-TENS phase. The experimental data were recorded, and the normality of each group was analyzed using the Shapiro-Wilk test in a statistical software program (IBM SPSS Statistics, v26.0). The paired-sample t test was used to compare the differences in the mean values of sEMG and the asymmetry index (As); the independent-sample t test was used to compare the activity index (Ac) and torque index (To) (α=.05).

RESULTS

Significant differences were observed in the mean potential values of TA, MM, LSCM, and RDA before and after TENS in the resting state and RTA, LMM, and RMM before and after TENS in the clenching state (P<.05). Moreover, although AsDA values showed a significant difference (P=.027) before and after TENS in the resting state, the differences in As values for the other muscles in the resting state were statistically similar. Furthermore, in each state, the mean values of Ac and To after TENS showed no significant differences before and after TENS (P>.05).

CONCLUSIONS

The resting EMG values of the TA and MM differed significantly before and after TENS. After TENS, the resting EMG activity decreased, whereas the functional EMG activity tended to increase.

Comparison of Pre- and Posttreatment Airway Volume in Patients with Temporomandibular Joint Disorders Treated with Ultra-Low Frequency Transcutaneous Electrical Nerve Stimulation Using Cone Beam Computed Tomography

Introduction  Temporomandibular joint disorders (TMD) present with a multitude of symptoms that can range from headaches to shoulder pain. Patients frequently present with pain in the ear, dizziness, and vertigo. It is noted that some patients who report TMDs also have a history of sleep disturbances, which is noted in cone beam computed tomography (CBCT) as a reduction in the oropharyngeal airway volume. Objective  To evaluate the airway volume in pre- and posttreatment of TMD with the use of neuromuscular orthotics made with ultra-low frequency transcutaneous electrical nerve stimulation (ULF-TENS). Methods  A total of 15 patients were evaluated for TMDs using the related criteria. Those included were treated with ULF-TENS with evaluation of the airway volume both pre- and posttreatment using CBCT and the Dolphin 3D volume analysis software. Results  While the symptoms were shown to be significantly reduced in patients who were treated with this particular modality, the airway volume varied in those who reported a reduction after a period of 3 months and those that reported after a period of 6 months. Conclusion  Posttreatment evaluation of the airway should be done after a period of 6 months for a more objective evaluation. A multidisciplinary evaluation of the patient is required in such cases.

Effects of an intraoral device (IOD) on electromyographic activity on the masseter and temporal muscles in Class III patients

OBJECTIVE

Class III malocclusion is characterized by a loss of vertical dimension associated with muscle imbalance. The present study was designed to determine electromyographic amplitude changes in temporal (T) and masseter (M) at rest and during clenching in Class III patients treated with an intraoral device (IOD) over a 24-hour period for 30 days with transcutaneous electrical nerve stimulation (TENS).

METHODS

Twelve patients with Class III (mean age 27.7 ± 1.2 years) were treated with TENS and IOD. Ten untreated patients composed the control group. Data were analyzed using Wilcoxon test and ANOVA.

RESULTS

Patients treated with TENS and IOD showed a marked decrease in hyperactivity of M and T at rest (p = 0.001) and an increase during clenching (p = 0.001). The control group maintained similar activity in both positions.

CONCLUSION

This study confirms that using TENS and IOD in patients improves muscle activity of T and M.

Craniofacial Sleep Medicine: The Important Role of Dental Providers in Detecting and Treating Sleep Disordered Breathing in Children

Obstructive sleep apnea (OSA) is a clinical disorder within the spectrum of sleep-related breathing disorders (SRDB) which is used to describe abnormal breathing during sleep resulting in gas exchange abnormalities and/or sleep disruption. OSA is a highly prevalent disorder with associated sequelae across multiple physical domains, overlapping with other chronic diseases, affecting development in children as well as increased health care utilization. More precise and personalized approaches are required to treat the complex constellation of symptoms with its associated comorbidities since not all children are cured by surgery (removal of the adenoids and tonsils). Given that dentists manage the teeth throughout the lifespan and have an important understanding of the anatomy and physiology involved with the airway from a dental perspective, it seems reasonable that better understanding and management from their field will give the opportunity to provide better integrated and optimized outcomes for children affected by OSA. With the emergence of therapies such as mandibular advancement devices and maxillary expansion, etc., dentists can be involved in providing care for OSA along with sleep medicine doctors. Furthermore, the evolving role of myofunctional therapy may also be indicated as adjunctive therapy in the management of children with OSA. The objective of this article is to discuss the important role of dentists and the collaborative approach between dentists, allied dental professionals such as myofunctional therapists, and sleep medicine specialists for identifying and managing children with OSA. Prevention and anticipatory guidance will also be addressed.

Ultra-Low Frequency Transcutaneous Electrical Nerve Stimulation on Pain Modulation in a Rat Model with Myogenous Temporomandibular Dysfunction

Masticatory myofascial pain (MMP) is one of the most common causes of chronic orofacial pain in patients with temporomandibular disorders. To explore the antinociceptive effects of ultra-low frequency transcutaneous electrical nerve stimulation (ULF-TENS) on alterations of pain-related biochemicals, electrophysiology and jaw-opening movement in an animal model with MMP, a total of 40 rats were randomly and equally assigned to four groups; i.e., animals with MMP receiving either ULF-TENS or sham treatment, as well as those with sham-MMP receiving either ULF-TENS or sham treatment. MMP was induced by electrically stimulated repetitive tetanic contraction of masticatory muscle for 14 days. ULF-TENS was then performed at myofascial trigger points of masticatory muscles for seven days. Measurable outcomes included maximum jaw-opening distance, prevalence of endplate noise (EPN), and immunohistochemistry for substance P (SP) and μ-opiate receptors (MOR) in parabrachial nucleus and c-Fos in rostral ventromedial medulla. There were significant improvements in maximum jaw-opening distance and EPN prevalence after ULF-TENS in animals with MMP. ULF-TENS also significantly reduced SP overexpression, increased MOR expression in parabrachial nucleus, and increased c-Fos expression in rostral ventromedial medulla. ULF-TENS may represent a novel and applicable therapeutic approach for improvement of orofacial pain induced by MMP.

The outcomes of ultrasonic and laser therapy in case of temporomandibular disorders – an evidence based update

Introduction. Temporomandibular disorders (TMDs) are considered multifactorial conditions, thereby with different therapy options, from occlusal equilibration, splint therapy, pharmacotherapy or physical therapy. Among the physical therapies, over the last years, laser therapy and ultrasound therapy have gained attention, as different experimental or clinical studies suggest their efficacy in case of TMDs. The aim of our literature review is to evaluate the available evidence on the effectiveness of laser and ultrasound therapy in the treatment of temporomandibular disorders. Material and method. A research of literature has been performed - articles published over the last 5 years (January 2016 until June 2021) were searched by introducing a combination of different terms, using the Pubmed, Scopus and Google Scholar databases. Results and discussions. A total number of 332 articles was found. For multiple publications regarding the same group of patients, the most recent studies were included. Initial analysis of titles and abstracts eliminated 232 articles, leaving 35 articles whose full text was examined. 20 articles met the inclusion criteria Conclusions. According to the findings of this literature update we can conclude that low level laser therapy, ultrasound therapy, and photobiomodulation may effectively reduce pain for patients suffering of muscular and joint TMDs. However, their effects appear to be only shortly maintained, and only for less complex cases. In addition, it was difficult to compare the studies included, as they do not offer an optimal usage (program, duration of sessions, or number of sessions) of each technique. In this context, we consider that further randomized clinical studies are necessarily to compare each physical technique as well as their synergic effect on the symptoms in case of temporomandibular disorders. Keywords: temporomandibular disorders, low level laser therapy, ultrasound therapy, photobiomodulation, TMD, LLLT

Effects of the lower jaw position on athletic performance of elite athletes

When an athlete wears a mouthguard, the position of the lower jaw is changed by virtue of the teeth being unable to occlude. Little research is available in in this area, which have indicated both positive impact and no positive impact.

Muskuloskeletale Erkrankungen und die kraniomandibuläre Dysfunktion – eine mögliche Ursache für nichterholsamen Schlaf

Methode

Kiefer- und Kopfgelenke bilden eine kybernetische Einheit. Ziel dieser Studie ist es, mögliche Zusammenhänge zwischen schlechtem Schlaf und der kraniozervikalen (CCD) bzw. kraniomandibulären Dysfunktion (CMD) zu ermitteln.

Ergebnisse

Von den 606 untersuchten CMD-CCD-Patienten mit schlechtem Schlaf waren 65,4 % der Patienten weiblich, 34,6 % männlich; 90,3 % erfüllten zusätzlich die diagnostischen Kriterien des Fibromyalgiesyndroms der Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften. Durch die synchrone Therapie der CMD bzw. CCD und der funktionellen Wirbelsäulenstörungen konnten bei 85 % der bislang therapieresistenten CMD-CCD-Patienten mit schlechtem Schlaf eine gute Besserung der Beschwerden im Körper und bei 81,5 % eine gute Schlafbesserung erzielt werden.

Diskussion

Die CMD/CCD kann als Folge chronischer Schmerzen auftreten. Umgekehrt kann eine CMD/CCD auch eine muskuloskeletale Störung hervorrufen oder unterhalten. Chronische Schmerzen können den Schlaf stören. Bei der Diagnose und Behandlung von Schlafstörungen muss auch auf eine CMD/CCD hin untersucht und diese ggf. mitbehandelt werden.

Evaluation of Arthrocentesis with and Without Platelet-Rich Plasma in the Management of Internal Derangement of Temporomandibular Joint: A Randomized Controlled Trial

PURPOSE

The purpose of this study was to compare the efficacy of intra-articular injection of platelet-rich plasma after arthrocentesis versus arthrocentesis alone as a treatment modality in patients with internal derangement of temporomandibular joint.

METHODS

Twenty-four patients suffering from internal derangement of temporomandibular joint were included in the study. The patients were randomly divided into two groups as follows-twelve patients underwent arthrocentesis followed by intra-articular injection of platelet-rich plasma (study group) and the other twelve were treated by arthrocentesis alone (control group). Pain intensity was recorded on visual analogue scale (VAS); maximum mouth opening and joint sound were measured before and after intervention. The patients were clinically evaluated at the intervals of 1 month, 3 and 6 months subsequently.

RESULTS

There was no statistically significant difference in all the parameters between the groups. Intra-group analysis showed statistically significant improvement in all the parameters.

CONCLUSION

In both groups, improvement of pain, maximum mouth opening and TMJ sound were observed at all intervals, but there was no statistically significant improvement in arthrocentesis with PRP group when compared with arthrocentesis alone.

A Device Improves Signs and Symptoms of TMD

Background

Temporomandibular joint dysfunction (TMD) therapy remains an open challenge for modern dentistry. Herein, we propose a new neuromuscular lingual device able to reduce signs and symptoms of TMD in female patients with chronic orofacial pain.

Methods

50 females with myofascial TMD according to RDC/TMD were randomly assigned to study (n = 25) and control groups (n = 25). At T0, both groups received sEMG/KNG and pain evaluation by the VAS scale. The study group received the ELIBA device (lingual elevator by Balercia) constructed under ULF-TENS (ultra-low-frequency transcoutaneous electrical nervous stimulation). Subjects were instructed to use ELIBA at least for 16 h/day. After 6 months (T1), both groups underwent to sEMG/KNG and VAS revaluation.

Results

T1 study group compared to controls showed a significant reduction in total (p < 0.0001) and mean (p < 0.0001) sEMG values, as well as a significant increase in both maximum vertical mouth opening (p=0.003) and maximum velocity in mouth opening (p=0.003) and closing (p < 0.0001). Interestingly, a significant reduction in pain measured by VAS (p < 0.0001) was reported.

Conclusions

After 6 months, the ELIBA device is able to significantly reduce TMD-associated myogenous pain and to promote the enhancement of sEMG/KNG values.

Practical Implications

ELIBA can be considered as a new device, potentially useful for head-neck pain relief in patients suffering from chronic TMD. In addition, its use promotes a muscles relaxation inducing freeway space increase. This characteristic makes it particularly useful for rehabilitation of patients with not enough space for construction of conventional orthotics or neuromuscular bites.

Usefulness of an occlusal device in the treatment of medication overuse headache and persistent idiopathic facial pain: preliminary results

There is a debate in literature about the therapeutic usefulness of oral devices in patients suffering from Medication Overuse Headache (MOH) or in patients suffering from Persistent Idiopathic Facial Pain (PIFP). From the case histories of 3356 patients, referred to us with a diagnosis of chronic craniofacial pain for assessment of the eventual application of an occlusal device to correct an impaired neuromuscular relationship between the mandible and the maxilla, we selected, following the criteria of the International Classification of Headache Disorders (ICHD-3beta), two groups of patients suffering from MOH and PIFP. All patients of the two groups underwent a Kinesiographic exam and an EMG to evaluate the freeway space (FWS). Patients presenting an impaired FWS were placed in treatment with the application of an occlusal device. At the follow-up after 6 months and after 1 year, we found a significant decrease in pain with regard to the intensity resulting in the reduction of clinical disability. The preliminary data collected using the VAS scale and the MIDAS questionnaire confirm that the neuromuscular cranio-mandibular system can have an important role in the diagnostic process of the MOH and the PIFP, suggesting the usefulness of treatment with an occlusal device, where there is adequate FWS.

Central Sensitization-Based Classification for Temporomandibular Disorders: A Pathogenetic Hypothesis

Dysregulation of Autonomic Nervous System (ANS) and central pain pathways in temporomandibular disorders (TMD) is a growing evidence. Authors include some forms of TMD among central sensitization syndromes (CSS), a group of pathologies characterized by central morphofunctional alterations. Central Sensitization Inventory (CSI) is useful for clinical diagnosis. Clinical examination and CSI cannot identify the central site(s) affected in these diseases. Ultralow frequency transcutaneous electrical nerve stimulation (ULFTENS) is extensively used in TMD and in dental clinical practice, because of its effects on descending pain modulation pathways. The Diagnostic Criteria for TMD (DC/TMD) are the most accurate tool for diagnosis and classification of TMD. However, it includes CSI to investigate central aspects of TMD. Preliminary data on sensory ULFTENS show it is a reliable tool for the study of central and autonomic pathways in TMD. An alternative classification based on the presence of Central Sensitization and on individual response to sensory ULFTENS is proposed. TMD may be classified into 4 groups: (a) TMD with Central Sensitization ULFTENS Responders; (b) TMD with Central Sensitization ULFTENS Nonresponders; (c) TMD without Central Sensitization ULFTENS Responders; (d) TMD without Central Sensitization ULFTENS Nonresponders. This pathogenic classification of TMD may help to differentiate therapy and aetiology.

Short-term transcutaneous electrical nerve stimulation reduces pain and improves the masticatory muscle activity in temporomandibular disorder patients: a randomized controlled trial

Studies to assess the effects of therapies on pain and masticatory muscle function are scarce.

Treating temporomandibular disorders with permanent mandibular repositioning: is it medically necessary?

In this paper, the authors review the rationale and history of mandibular repositioning procedures in relation to temporomandibular disorders (TMDs) as these procedures have evolved over time. A large body of clinical research evidence shows that most TMDs can and should be managed with conservative treatment protocols that do not include any mandibular repositioning procedures. Although this provides a strong clinical argument for avoiding such procedures, very few reports have discussed the biologic reasons for either accepting or rejecting them. This scientific information could provide a basis for determining whether mandibular repositioning procedures can be defended as being medically necessary. This position paper introduces the biologic concept of homeostasis as it applies to this topic. The continuing adaptability of teeth, muscles, and temporomandibular joints throughout life is described in terms of homeostasis, which leads to the conclusion that each person's current temporomandibular joint position is biologically "correct." Therefore, that position does not need to be changed as part of a TMD treatment protocol. This means that irreversible TMD treatment procedures, such as equilibration, orthodontics, full-mouth reconstruction, and orthognathic surgery, cannot be defended as being medically necessary.

Dysregulation of the descending pain system in temporomandibular disorders revealed by low-frequency sensory transcutaneous electrical nerve stimulation: a pupillometric study

Using computerized pupillometry, our previous research established that the autonomic nervous system (ANS) is dysregulated in patients suffering from temporomandibular disorders (TMDs), suggesting a potential role for ANS dysfunction in pain modulation and the etiology of TMD. However, pain modulation hypotheses for TMD are still lacking. The periaqueductal gray (PAG) is involved in the descending modulation of defensive behavior and pain through μ, κ, and δ opioid receptors. Transcutaneous electrical nerve stimulation (TENS) has been extensively used for pain relief, as low-frequency stimulation can activate µ receptors. Our aim was to use pupillometry to evaluate the effect of low-frequency TENS stimulation of μ receptors on opioid descending pathways in TMD patients. In accordance with the Research Diagnostic Criteria for TMD, 18 females with myogenous TMD and 18 matched-controls were enrolled. All subjects underwent subsequent pupillometric evaluations under dark and light conditions before, soon after (end of stimulation) and long after (recovery period) sensorial TENS. The overall statistics derived from the darkness condition revealed no significant differences in pupil size between cases and controls; indeed, TENS stimulation significantly reduced pupil size in both groups. Controls, but not TMD patients, displayed significant differences in pupil size before compared with after TENS. Under light conditions, TMD patients presented a smaller pupil size compared with controls; the pupil size was reduced only in the controls. Pupil size differences were found before and during TENS and before and after TENS in the controls only. Pupillometry revealed that stimulating the descending opioid pathway with low-frequency sensory TENS of the fifth and seventh pairs of cranial nerves affects the peripheral target. The TMD patients exhibited a different pattern of response to TENS stimulation compared with the controls, suggesting that impaired modulation of the descending pain system may be involved in TMD.

Positive outcome of occlusal freeway space reestablishment in patients with medication overuse due to chronic migraine

Considering the great chapter of migraines, it is important to note the signs and symptoms caused by an alteration of the relationship of the facial musculature and the occlusal freeway space (FWS) that is the distance from maximal intercuspation to the habitual rest position (measurable in 1.4-2.5 mm). To any mandible position changing (detected by periodontal, muscle and joint proprioceptors), there is an influence on the neuromuscular system and then an alteration of the FWS. A group of 60 patients with chronic migraine (CM) underwent a withdrawal of overused medication and were subjected to electromyographic and kinesiographic evaluation. All those who presented an alteration of the FWS at rest position have been subjected to treatment with orthosis device for about 12 months. The aim of our work is to obtain and define a correct mandibular position, physiological, in agreement with the neuromuscular structures of the patient. Clinical results obtained on this pool of patients, in terms of reduction of the VAS, let us understand the importance of the inviolability of the FWS and to eliminate any type of mandibular deviation with respect to the closure trajectory induced by TENS in patients suffering from CM.

Comparison between sensory and motor transcutaneous electrical nervous stimulation on electromyographic and kinesiographic activity of patients with temporomandibular disorder: a controlled clinical trial

Background

The purpose of the present controlled clinical trial was to assess the effect of a single 60 min application of transcutaneous electrical nervous stimulation (TENS) at sensory stimulation threshold (STS), compared to the application of motor stimulation threshold (MTS) as well as to untreatment, on the surface electromyographic (sEMG) and kinesiographic activity of patients with tempormanbibular disorder (TMD).

Methods

Sixty female subjects, selected according to the inclusion/exclusion criteria, suffering from unilateral TMD in remission were assigned to MTS, STS or untreatment. Pre- and post-treatment differences in the sEMG activity of temporalis anterior (TA), masseter (MM), digastric (DA) and sternocleidomastoid muscles (SCM), as well in the interocclusal distance (ID), within group were tested using the Wilcoxon test, while differences among groups were assessed by Kruskal-Wallis test; the level of significance was set at p ≤ 0.05.

Results

Significant pre- and post-treatment differences were observed in MTS and STS groups, for TA and MM of both sides; no significant difference was detected between MTS and STS groups. Kinesiographic results showed that the vertical component of ID was significantly increased after TENS in MTS and STS groups.

Conclusions

STS TENS could be effective, as well as MTS, in reduce the sEMG activity of masticatory muscles and to improve the ID of TMD patients in remission. Future studies are needed to confirm the results of the present study. Clinical relevance. The present study demonstrates that the application of TENS is effective in reduce the sEMG activity, as well as in increasing the ID of patients with TMD; our study did not support superior effectiveness of MTS or STS.

Trial registration

ClinicalTrials.gov: NCT01832207

Dental occlusion, body posture and temporomandibular disorders: where we are now and where we are heading for

The aim of this investigation was to perform a review of the literature dealing with the issue of relationships between dental occlusion, body posture and temporomandibular disorders (TMD). A search of the available literature was performed to determine what the current evidence is regarding: (i) The physiology of the dental occlusion-body posture relationship, (ii) The relationship of these two topics with TMD and (iii) The validity of the available clinical and instrumental devices (surface electromyography, kinesiography and postural platforms) to measure the dental occlusion-body posture-TMD relationship. The available posturographic techniques and devices have not consistently found any association between body posture and dental occlusion. This outcome is most likely due to the many compensation mechanisms occurring within the neuromuscular system regulating body balance. Furthermore, the literature shows that TMD are not often related to specific occlusal conditions, and they also do not have any detectable relationships with head and body posture. The use of clinical and instrumental approaches for assessing body posture is not supported by the wide majority of the literature, mainly because of wide variations in the measurable variables of posture. In conclusion, there is no evidence for the existence of a predictable relationship between occlusal and postural features, and it is clear that the presence of TMD pain is not related with the existence of measurable occluso-postural abnormalities. Therefore, the use instruments and techniques aiming to measure purported occlusal, electromyographic, kinesiographic or posturographic abnormalities cannot be justified in the evidence-based TMD practice.