Can temporomandibular disorder symptoms and headaches be prevented in 13- to 15-year-old girls by information provided in a school setting?

OBJECTIVE

Temporomandibular disorders (TMD) may develop, especially among girls, during the adolescence period. The aim of this study was to study if information and advice in a school setting could prevent development of TMD symptoms and headaches during the early teenage period.

METHODS

Thirteen-year-old girls, at 19 upper elementary schools were invited to participate in a study with structured information about the jaw system, TMD symptoms and risk factors, as well as advice how to manage risk factor and TMD. Six hundred and fifty-one girls enrolled, of which 507 girls were followed for 2-2.5 years. Half received information on three occasions (cases), and the other half served as controls. Included in the analysis of incidence of TMD symptoms were those without frequently occurring TMD symptoms (not including headaches) at baseline (n = 396) and included in the analysis of incidence of headaches were those without frequent headaches at baseline (n = 297).

RESULT

The 2-year incidence of TMD symptoms was significantly lower in the information cohort (19%) compared to the controls (28%) (p = .03). The 2-year incidence of headaches was lower among those who were allocated to information (30%) compared to controls (40%), but the difference was not statistically significant (p = .099). Cases who had headaches at baseline reported a significantly lower prevalence at follow-up compared to controls (p = .03).

CONCLUSION

Standardized information in school settings can prevent development of TMD symptoms and headaches among young girls.

Ultrasonographic examination of masticatory muscles in patients with TMJ arthralgia and headache attributed to temporomandibular disorders

This study used ultrasonography to compare the thickness and cross-sectional area of the masticatory muscles in patients with temporomandibular joint arthralgia and investigated the differences according to sex and the co-occurrence of headache attributed to temporomandibular disorders (HATMD). The observational study comprised 100 consecutive patients with TMJ arthralgia (71 females and 29 males; mean age, 40.01 ± 17.67 years) divided into two groups: Group 1, including 86 patients with arthralgia alone (60 females; 41.15 ± 17.65 years); and Group 2, including 14 patients with concurrent arthralgia and HATMD (11 females; 33.00 ± 16.72 years). The diagnosis of TMJ arthralgia was based on the diagnostic criteria for temporomandibular disorders. The parameters of the masticatory muscles examined by ultrasonography were subjected to statistical analysis. The pain area (2.23 ± 1.75 vs. 5.79 ± 2.39, p-value = 0.002) and visual analog scale (VAS) score (3.41 ± 1.82 vs. 5.57 ± 12.14, p-value = 0.002) were significantly higher in Group 2 than in Group 1. Muscle thickness (12.58 ± 4.24 mm) and cross-sectional area (4.46 ± 2.57 cm2) were larger in the masseter muscle than in the other three masticatory muscles (p-value < 0.001). When examining sex-based differences, the thickness and area of the masseter and lower temporalis muscles were significantly larger in males (all p-value < 0.05). The area of the masseter muscle (4.67 ± 2.69 vs. 3.18 ± 0.92, p-value = 0.004) and lower temporalis muscle (3.76 ± 0.95 vs. 3.21 ± 1.02, p-value = 0.049) was significantly smaller in Group 2 than in Group 1. An increase in VAS was significantly negatively correlated with the thickness of the masseter (r =  - 0.268) and lower temporalis (r =  - 0.215), and the cross-sectional area of the masseter (r =  - 0.329) and lower temporalis (r =  - 0.293). The masseter and lower temporalis muscles were significantly thinner in females than in males, and their volumes were smaller in patients with TMJ arthralgia and HATMD than in those with TMJ arthralgia alone. HATMD and decreased masseter and lower temporalis muscle volume were associated with increased pain intensity.

Evaluation of single session physical therapy methods in bruxism patients using shear wave ultrasonography

OBJECTIVE

To compare the immediate effects of a single session of manual therapy (MT) or Kinesio taping following MT (KTMT) in patients with bruxism using shear wave ultrasonography.

METHODS

Twenty patients were included in the MT group (mean age 27.3 ± 4.8), and 19 patients were included in the KTMT group (age mean 26.2 ± 5.4), randomly. Muscle thickness and stiffness were assessed via shear wave ultrasonography, and pain pressure threshold was assessed with an algometer before and after one session of MT or KTMT.

RESULTS

Significant decreases were found in muscle thickness and stiffness of the bilateral masseter (p < 0.05). Significant decrease in pain was seen in the masseter and temporalis muscle PPT measurements in the KTMT group (p < 0.05) only.

CONCLUSION

Kinesio taping in addition to MT is recommended in the immediate physiotherapy treatment of bruxism for acute pain.

Does difficulty in chewing induce subjective musculoskeletal symptoms? A case-control study

OBJECTIVES

Risk factors associated with the development of musculoskeletal disorders and symptoms remain an important issue worldwide. This study aimed to investigate the relationship between oral health problems such as difficulty chewing and the occurrence of stiff neck/shoulders (SN/S) and low back pain (LBP).

DESIGN

Case-control study.

SETTING AND PARTICIPANTS

This study was conducted from 1 April 2018 to 31 March 2020. The subjects were 77 341 workers among 646 281 workers from several employers in Japan.

OUTCOME MEASURES

Participants were asked to evaluate their subjective SN/S and LBP symptoms using a self-administered questionnaire.

METHODS

We defined the chewing condition using a questionnaire, and workers who responded with 'I can chew anything' were classified as the good condition group (GCG), and those who responded with 'Sometimes I have difficulty chewing due to problems with the teeth, gums, or bite' or 'I can hardly chew' were classified as the poor condition group (PCG). Setting the year 2018 as the baseline, we performed a logistic regression model using propensity score and inverse probability weighting (IPW) methods and chewing condition groups as explanatory variables and SN/S and LBP as objective variables.

RESULTS

The IPW-adjusted logistic regression model showed that the OR of SN/S was approximately 1.25 (95% CI 1.17 to 1.33) times higher in the PCG than that in the GCG (p<0.001). Similarly, the OR of LBP was about 1.37 (95% CI 1.27 to 1.48) times higher in the PCG than that in the GCG in the IPW-adjusted logistic regression model (p<0.001).

CONCLUSIONS

Our study suggests that the occurrence of SN/S and LBP symptoms in workers could be predicted depending on the presence of difficulty in chewing. Therefore, oral health and health guidance are gaining importance for the prevention of subjective musculoskeletal symptoms.

Oral Behaviors and Parafunctions: Comparison of Temporomandibular Dysfunction Patients and Controls

The aim of this study is to evaluate the frequency of oral behaviors in patients with temporomandibular disorders (TMD) and a control group without TMD.In this baseline case-control study, 260 controls and 260 subjects with TMD completed the oral behaviors checklist defined as a "self-report scale for identifying and quantifying the frequency of jaw overuse behavior" and underwent clinical examinations using the DC/TMJ international examination form (version May 12, 2013). Relationships of oral parafunctions' frequencies between groups were examined. The statistical analysis was performed with IBM SPSS Statistics 23 software.Age and gender distribution in the study groups did not reveal statistical differences (P > 0.05). Multivariate logistic regression analysis was conducted to establish system of independent oral behaviors for prognosis TMD. The stepwise regression analysis demonstrated that very frequent expression of holding, tightening, or tense muscles is associated with 10.83 times (P < 0.05) higher risk of TMD, grinding teeth together during waking hours with 4.94 times (P < 0.05) higher risk, and sustained talking with 2.64 times (P < 0.05) higher risk of TMD. By contrast, it was determined that 3 oral behaviors were less common in the TMD patients compared with the control group: clenching teeth together during waking hours, facing grimaces, and yawning (P < 0.05). The individuals with TMD reported a significantly higher frequency of 10 behaviors (P < 0.05), 3 of which may be regarded as independent risk factors for TMD. In addition, 3 oral behaviors were more frequently observed in the healthy subjects than in the TMD patients.

Effects of stress and relaxation on pain perception in subjects with pain-free occlusional disharmony compared with healthy controls

OBJECTIVES

The significance of occlusal disharmony for the development of painful temporomandibular disorder (TMD) is controversial. The ongoing biomechanical strain caused by occlusal disharmony might lead to sensitization processes in the nociceptive system. Understanding these processes might be an important step toward understanding the possible relationship between occlusal disharmony and TMD. In this study, we therefore investigated whether subjects with occlusal disharmony (n = 22) differ from healthy controls (n = 26) in their pain perception and pain modulation by stress and relaxation.

MATERIALS AND METHODS

Trigeminal and extratrigeminal experimental pain perception (pinprick, heat, and pressure pain) was assessed before and after stress (mental arithmetic) and relaxation (viewing of low-arousal pictures).

RESULTS

There were no group differences in pain perception at baseline or during the stress task. Compared with controls, the occlusal disharmony group exhibited an inadequate reduction in pain perception during relaxation, which was significant for the extratrigeminal site (P < 0.01) and reached a trend for significance at the trigeminal site (P = 0.1).

CONCLUSIONS

These results suggest that subjects with occlusal disharmony show signs of disturbed endogenous pain inhibition during relaxation.

CLINICAL RELEVANCE

There is evidence for the presence of sensitization of the nociceptive system in subjects with occlusal disharmony. Possibly, deficient inhibition of extratrigeminal and trigeminal pain perception by relaxation might contribute to the development of TMD or other chronic pain disorders.

Digital Evaluation of Functional Occlusion Parameters and their Association with Temporomandibular Disorders

CONTEXT

Dental researchers are contradictory in their opinion on the role of occlusion in TMD. Occlusal evaluation of both conventional and digital methods in TMD patients will provide the accurate information about the factors accountable for occlusal instability. Identifying the factors responsible will facilitate precise diagnosis and treatment for TMD.

AIM

The AIM of the study was to determine the dynamic occlusal parameters strongly associated with the etiology of Temporomandibular disorders.

MATERIAL AND METHODS

Study group consisted of 100 patients; it included 50 patients with normal TMJ(Group I) and remaining 50 patients had a minimum of one positive sign or symptom of Temporomandibular disorder (GroupII). The patient's dynamic occlusal contacts were evaluated by both conventional and digital methods. The Articulating paper was utilized for conventional occlusion analysis. During conventional analysis centric, lateral and protrusive interferences were evaluated along with loss of vertical dimension. Digital occlusal analysis was performed with T-Scan III. Clusion time, disclusion times were recorded for both groups. Chi-square and Student't' statistical analyses were performed to ascertain the association and statistically significant difference between the groups using SPSS19.

RESULTS

Group II patients predominantly (66%)had Group-function occlusion compared to Group I subject. Centric slide more than 2 mm found to have strong influence (p value 0.008) on the etiology of TMD. Among the occlusal interferences evaluated balanced side interferences had a strong correlation with TMD with p-value of 0.003. Working side interferences, protrusive interferences had a p-value of 0.157, 0.826 respectively, indicating weak association. T-Scan analysis showed Group I had 0.689, 0.9136, 0.7952, 0.9794 seconds of clusion, left, right, protrusive disclusion time respectively compared to corresponding 1.862, 1.7995, 1.6978, 1.9296 seconds for Group II. Statistically significant difference (p≤0.05) was found between the mean values of both groups.

CONCLUSION

Among the dynamic occlusal parameters evaluated centric slide and balancing side interferences were found to be highly influential in TMD etiology. TMD patients had prolonged clusion and disclusion times compared to healthy TMJ patients.

The dental occlusion as a suspected cause for TMDs: epidemiological and etiological considerations

The relationship between the dental occlusion and temporomandibular disorders (TMDs) has been one of the most controversial topics in the dental community. In a large epidemiological cross-sectional survey - the Study of Health in Pomerania (Germany) - associations between 15 occlusion-related variables and TMD signs or symptoms were found. In other investigations, additional occlusal variables were identified. However, statistical associations do not prove causality. By using Hill's nine criteria of causation, it becomes apparent that the evidence of a causal relationship is weak. Only bruxism, loss of posterior support and unilateral posterior crossbite show some consistency across studies. On the other hand, several reported occlusal features appear to be the consequence of TMDs, not their cause. Above all, however, biological plausibility for an occlusal aetiology is often difficult to establish, because TMDs are much more common among women than men. Symptom improvement after insertion of an oral splint or after occlusal adjustment does not prove an occlusal aetiology either, because the amelioration may be due to the change of the appliance-induced intermaxillary relationship. In addition, symptoms often abate even in the absence of therapy. Although patients with a TMD history might have a specific risk for developing TMD signs, it appears more rewarding to focus on non-occlusal features that are known to have a potential for the predisposition, initiation or perpetuation of TMDs.

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.

Some dogmas related to prosthodontics, temporomandibular disorders and occlusion

It is the aim of this paper to give a few examples of dogmas related to prosthodontics and oral implants and to discuss the controversial role of occlusion in the aetiology of temporomandibular disorders. New knowledge is developing at a rapidly increasing rate in dentistry, as in other areas of society. Our lecturers at university taught us many useful things. But, as time goes by, what is still relevant? Some methods are so well established that they deserve to be called dogmas. It is implied that a dogma is not supported by strong evidence, even though it has existed and been practised for a long time. In the era of evidence-based dentistry it is appropriate to scrutinize such issues. A review of the current literature indicates that conflicting opinions exist concerning a number of common procedures in clinical dentistry, mainly due to a scarcity of good studies with unambiguous results. There is therefore a need for more high-quality clinical research in attempting to reach the goal of evidence-based clinical practice. The dental community should take an active part in this process.