Effect of lengthy root canal therapy sessions on temporomandibular joint and masticatory muscles

Low-level laser therapy in the management of muscle fatigue caused after long Endodontic procedure

Background

The masticatory muscles may undergo fatigue due to prolonged mouth opening during the endodontic procedures. Low-level laser can be used to treat muscle fatigue due its capacity to produce reactive oxygen species and improve function of mitochondria. Aim: To determine the effectiveness of low-level laser therapy in the management of masticatory muscle fatigue caused after long endodontic procedure under Local anesthesia.

Material and Methods

44 patients complaining of reduced mouth opening and pain while mouth opening, after long endodontic therapy were considered for the study and were randomly allocated into study and control group. In the study group, low-level laser was applied while patients of control group didn't receive any therapy. In the study group, Visual analogue scale (VAS) score of pain was taken after endodontic therapy, immediately after laser therapy and 4 hours after endodontic therapy. Mouth opening of the patients was measured, before and after endodontic procedure and immediately after laser therapy. In the control group, VAS score of pain was recorded immediately after endodontic therapy and 4 hours after endodontic therapy. Statistical analysis used: ANOVA test and un-paired t-test was used for the data analysis.

Results

When both groups were compared, a statistically significant (P=0.0000) reduction with fatigue was found.

Conclusions

The low-level laser can be a useful procedure immediately post long endodontic procedure causing masticatory muscle fatigue. Hence, this therapy can be considered as an add-on therapeutic procedure along with prolonged endodontic appointments to relieve the patient from the discomfort. Key words:Muscle fatigue, Masticatory muscles, Low-level laser therapy.

Temporomandibular Disorders and Bruxism among Sex Workers-A Cross Sectional Study

Sex workers are a highly underprivileged population which is present all around the world. Sex work is associated with negative social stigma which affects all aspects of the sex workers' lives including healthcare, service providers and police. The stigma may result in increased stress, mental health problems, feelings of isolation and social exclusion. In the present study, 36 sex workers (SW) and 304 subjects from the general population in Israel (GP) were evaluated for the presence of bruxism and Temporomandibular disorders (TMD), with the use of Diagnostic Criteria for Temporomandibular Disorders (DC/TMD- Axis I). When compared to the general population, sex workers presented larger maximal assisted mouth opening and higher prevalence of the following TMD diagnoses: Disc displacement with reduction, Myalgia, Myofascial pain with referral, Arthralgia (left and right) and Headache attributed to TMD. The odds of sex workers suffering from one of these diagnoses were twice to five times higher than those of the general population. The study shows that health problems of sex workers go beyond venereal diseases, HIV and mental disorders which are commonly studied. Oral health, TMD and oral parafunctions are some of the additional health issues that should be addressed and explored in this population.

The variables associated with dental anxiety and their management in primary care dental clinics in Bahrain: a cross-sectional study

Background

20–80% of adults presenting to a dental clinic experience anxiety. Negative past dental experiences and environmental factors such as the waiting area of a dental clinic or sound of a drill are commonly considered triggering factors for anxiety. Anxiety management strategies are considered a part of routine dental procedure, due to increased prevalence and compromised patient care. Hence the aim of the present study is to identify the prevalence and variables associated with dental anxiety and their management in patients visiting the primary care dental clinics in Bahrain.

Method

Four hundred and eighty participants were included. A 3-part questionnaire deciphered the demographic characteristics of the participants, the dental procedure undertaken, the level of anxiety, and the management strategy used by the dentist. The pre and post-treatment MDAS scores were recorded. Paired t test, ANOVA and Wilcoxon signed rank test was used to test the level of significance between the variables and the mean MDAS scores. The p ≤ 0.05 was considered statistically significant.

Results

The prevalence of dental anxiety was 23.7% with moderate anxiety, and 11.4% with high anxiety. Females presented with a higher mean MDAS both pre and post-treatment compared with males. A statistically significant difference between the pre and post-treatment MDAS scores were observed in educated patients less than 50 years of age. Those with unpleasant previous dental experience showed statistically significant difference. Analyses of anxiety management techniques showed that single techniques worked better than combination techniques. Rest and breaks combined with any other technique of choice showed significant reduction in the MDAS scores post treatment.

Conclusion

To conclude, all patients attending the dental clinic present with some level of anxiety that necessitates the dentist to use anxiety management strategies. Non-pharmacological methods that are non-invasive must be the first choice. Rests and breaks, with any technique of choice provides the best possible anxiety management. It is possible to achieve the desired anxiety reduction in single visit to complete the planned dental intervention, other than in patients who are dental phobic.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-022-02173-7.

A novel rat model of temporomandibular disorder with improved face and construct validities

AIMS

Temporomandibular disorders are a cluster of orofacial conditions that are characterized by pain in the temporomandibular joint (TMJ) and surrounding muscles/tissues. Animal models of painful temporomandibular dysfunction (TMD) are valuable tools to investigate the mechanisms responsible for symptomatic temporomandibular joint and associated structures disorders. We tested the hypothesis that a predisposing and a precipitating factor are required to produce painful TMD in rats, using the ratgnawmeter, a device that determines temporomandibular pain based on the time taken for the rat to chew through two obstacles.

MATERIALS AND METHODS

Increased time in the ratgnawmeter correlated with nociceptive behaviors produced by TMJ injection of formalin (2.5%), confirming chewing time as an index of painful TMD. Rats exposed only to predisposing factors, carrageenan-induced TMJ inflammation or sustained inhibition of the catechol-O-methyltransferase (COMT) enzyme by OR-486, showed no changes in chewing time. However, when combined with a precipitating event, i.e., exaggerated mouth opening produced by daily 1-h jaw extension for 7 consecutive days, robust function impairment was produced.

KEY FINDINGS

These results validate the ratgnawmeter as an efficient method to evaluate functional TMD pain by evaluating chewing time, and this protocol as a model with face and construct validities to investigate symptomatic TMD mechanisms.

SIGNIFICANCE

This study suggests that a predisposition factor must be present in order for an insult to the temporomandibular system to produce painful dysfunction. The need for a combined contribution of these factors might explain why not all patients experiencing traumatic events, such as exaggerated mouth opening, develop TMDs.

Degenerative joint disease in the temporomandibular joint with fibrous ankylosis in a rhesus macaque (Macaca mulatta)

Background

Ankylosis in the temporomandibular joint (TMJ) is known to have various etiologies in veterinary medicine. We observed a case of fibrous ankylosis of the TMJ in a newly imported rhesus monkey (Macaca mulatta).

Case presentation

Moderate to severe attrition was found in the middle labial portion of the left maxillary canine. No tenderness around the jaw was detected in the physical examination. The WBC count, CRP level, rheumatoid factor level, and other parameters were normal. Irregularity in the joint surface was observed in both TMJs in the radiographic and computed tomographic examinations, but the left TMJ presented more severe irregularity. It was determined that the removal of the locked portion of the left canine would alleviate the case of lockjaw and allow intubation with an endotracheal tube. Canine tooth crown reduction was performed for both canine teeth. The mouth opening distance slightly (approximately 5 mm) increased up to 20 mm. We concluded that the attrition of canine teeth was not the reason for lockjaw and ankyloses originating from TMJ disease. Fibrotic synovial tissue and joint surface irregularity were observed by necropsy. The presence of fibrocartilage in most areas of the TMJ was confirmed by histology. The diagnosis was fibrous ankylosis of the TMJ associated with DJD.

Conclusions

To the best of our knowledge, this is the first report of degenerative joint disease of the TMJ in a rhesus monkey with fibrous ankylosis of the TMJ.

Pain Sensitivity Modifies Risk of Injury-Related Temporomandibular Disorder

This study evaluates contributions of jaw injury and experimental pain sensitivity to risk of developing painful temporomandibular disorder (TMD). Data were from the Orofacial Pain: Prospective Evaluation and Risk Assessment (OPPERA) nested case-control study of incident painful TMD. Injury and subsequent onset of painful TMD were monitored prospectively for ≤5 y in a community-based sample of 409 US adults who did not have TMD when enrolled. At baseline, thermal-pressure and pinprick pain sensitivity, as potential effect modifiers, were measured using quantitative sensory testing. During follow-up, jaw injury from any of 9 types of potentially traumatic events was determined using quarterly (3-monthly) health update questionnaires. Study examiners classified incident painful TMD, yielding 233 incident cases and 176 matched controls. Logistic regression models, estimated incidence odds ratios (IORs), and 95% confidence limits (CLs) were used for the association between injury and subsequent onset of painful TMD. During follow-up, 38.2% of incident cases and 13.1% of controls reported 1 or more injuries that were 4 times as likely to be intrinsic (i.e., sustained mouth opening or yawning) as extrinsic (e.g., dental visits, whiplash). Injuries due to extrinsic events (IOR = 7.6; 95% CL, 1.6–36.2), sustained opening (IOR = 5.4; 95% CL, 2.4–12.2), and yawning (IOR = 3.4; 95% CL, 1.6–7.3) were associated with increased TMD incidence. Both a single injury (IOR = 6.0; 95% CL, 2.9–12.4) and multiple injuries (IOR = 9.4; 95% CL, 3.4,25.6) predicted greater incidence of painful TMD than events perceived as noninjurious (IOR = 1.9; 95% CL, 1.1–3.4). Injury-associated risk of painful TMD was elevated in people with high sensitivity to heat pain (IOR = 7.4; 95% CL, 3.1–18.0) compared to people with low sensitivity to heat pain (IOR = 3.9; 95% CL, 1.7–8.4). Jaw injury was strongly associated with elevated painful TMD risk, and the risk was amplified in subjects who had enhanced sensitivity to heat pain at enrollment. Commonly occurring but seemingly innocuous events, such as yawning injury, should not be overlooked when judging prognostic importance of jaw injury.

Differential diagnoses for persistent pain after root canal treatment: a study in the National Dental Practice-based Research Network

INTRODUCTION

Pain present 6 months after root canal treatment (RCT) may be of odontogenic or nonodontogenic origin. This is important because treatments and prognoses are different; therefore, the aim of this study was to provide specific diagnoses of patients reporting pain 6 months after receiving initial orthograde RCT.

METHODS

We enrolled patients from the Midwest region of an existing prospective observational study of pain after RCT. Pain at 6 months was defined as ≥1 day of pain and average pain intensity of at least 1 of 10 over the preceding month. An endodontist and an orofacial pain practitioner independently performed clinical evaluations, which included periapical and cone-beam computed tomographic radiographs, to determine diagnoses.

RESULTS

Thirty-eight of the 354 eligible patients in the geographic area (11%) met the pain criteria, with 19 (50%) consenting to be clinically evaluated. As the sole reason for pain, 7 patients (37%) were given odontogenic diagnoses (4 involving the RCT tooth and 3 involving an adjacent tooth). Eight patients (42%) were given nonodontogenic pain diagnoses (7 from referred temporomandibular disorder pain and 1 from persistent dentoalveolar pain disorder). Two patients (11%) had both odontogenic and nonodontogenic diagnoses, whereas 2 (11%) no longer fit the pain criteria at the time of the clinical evaluation.

CONCLUSIONS

Patients reporting "tooth" pain 6 months after RCT had a nonodontogenic pain diagnosis accounting for some of this pain, with temporomandibular disorder being the most frequent nonodontogenic diagnosis. Dentists should have the necessary knowledge to differentiate between these diagnoses to adequately manage their patients.