Management of pain in TMD patients: Bio-oxidative ozone therapy versus occlusal splints

Objective: To compare the effects of bio-oxidative ozone application with occlusal splints in temporomandibular disorder (TMD) patients with pain.

Methods: Forty participants were selected after the diagnosis of TMD and randomly divided into two groups: ozone group (OG, n = 20) and occlusal splint group (OCSG, n = 20). Ozone was applied to patients three times per week, for a total of six sessions. Patients in the OCSG were instructed to use occlusal splints every night over a period of four weeks.

Results: Mandibular movements showed significant differences for the time factor in OG and OCSG. Pressure pain thresholds of the temporal and masseter muscles at follow-up were significantly higher in the OCSG group. Both treatments statistically decreased the visual analog scale (VAS) scores. However, no statistically significant difference was observed between groups after the application of treatments.

Discussion: Occlusal splint treatment is still the gold treatment modality for objective pain relief in patients with TMD pain.     

Efficacy of Appliance Therapy on Temporomandibular Disorder Related Facial Pain and Mandibular Mobility: A Randomized Controlled Study

There is limited evidence supporting the role of occlusal splints in Temporomandibular disorder (TMD) therapy. The aim of this randomized controlled clinical trial was to assess the efficacy of stabilization splint therapy on TMD related facial pain and mandibular mobility. The sample of study consisted of eighty consecutive patients diagnosed with TMD. Patients were randomly assigned into two groups: a splint group (n = 40) comprising of patients treated with stabilization splint, councelling and masticatory muscle exercises, and a control group (n = 40), comprising of patients treated with councelling and masticatory muscle exercises alone. Data from both the groups were collected at the beginning of the study and after a 6-month follow up. The outcome variables were visual analogue scale on facial pain intensity and clinical findings for TMD (anterior maximal opening, mandibular right laterotrusion, mandibular left laterotrusion, mandibular protrusion, and number of painful muscle sites). Changes within the splint and control groups (before treatment and 6 months after treatment) were analyzed using paired samples t test. Differences in change between the splint and control groups were analyzed using independent samples t-test. The level of significance was set at p < 0.05. Facial pain and number of painful muscle sites decreased, and the mandibular mobility increased significantly in both groups after treatment; however the differences in changes in VAS or clinical TMD findings between the two groups were not statistically significant. The findings of this study show that stabilization splint treatment in combination with counselling and masticatory muscle exercises has no additional benefit in relieving facial pain and increasing the mobility of the mandible than counselling and masticatory muscle exercises alone over a 6-months’ time interval.     

Effect of orthognathic surgery on masticatory performance and muscle activity in skeletal Class III patients

Objective: To evaluate the effect of double jaw orthognathic surgery (OGS) on masticatory performance and electromyographic activity of the masseter and anterior temporal muscles in skeletal Class III patients.

Methods: Individuals were instructed to chew standardized round tablets of silicone impression material. The cumulative weight percentage was calculated using sieve analysis. The bilateral surface electromyographic activity of the muscles was evaluated. Following the orthodontic treatment, a stabilization splint was fabricated. Patients were instructed to wear it full-time until the surgical procedure occurred. Recordings were performed before the splint application (T0), after the splint application (T1), 1 month after the OGS (T2), and 6–8 months after the OGS (T3).

Results: Median particle size of the chewed silicone material did not differ from T0 to T1 with the use of an occlusal splint (p > 0.05). However, it decreased from 9.46 to 6.92 cm from T2 to T3. From T0 to T3, a statistically significant decrease was found, following the surgical intervention (p < 0.01). A significant decrease in masticatory muscle activity was also observed during the relaxation test from T0 to T3, at which time it reached the control group value.

Discussion: OGS enhanced masticatory function by improving occlusion in individuals with a dentofacial deformity.     

Influence of Different Centric Functions on Electromyographic Activity of Elevator Muscles

This study compares eight different occlusal centric functions with splint contact on different teeth in order to determine their influence on mandibular elevator electromyographic (EMG) activity.

Maxillary occlusal splints were built for eight subjects without craniomandibular dysfunction. Investigators divided each splint into three parts, in order to record different occlusal schemes in the same subject without varying the vertical dimension. EMG activity in the left masseter and anterior temporal muscles was registered during maximum voluntary clenching.

Results showed higher masseter activity with the splint than without, and anterior temporal activity was similar. There was a significant decrease of EMG activity with the anterior section of the splint. There were no significant differences between the remaining centric functions and clenching with the complete splint, except for the centric function with contralateral posterior contact, in which elevator activity was significantly reduced.

Results suggest that bilateral posterior occlusal stabilization is critical for maximum interocclusal force.     

Evaluation of occlusal splint therapy in temporomandibular joint disorder patients using real‐time ultrasonography

Aim: The aim of the present study was to evaluate the effect of occlusal splint therapy by determining the cross‐sectional dimension of masseter muscle using ultrasound in patients with temporomandibular joint disc displacement with reduction. Methods: Twenty‐seven patients aged between 20 and 40 years were included in the study. A detailed history was obtained, and a comprehensive clinical examination was carried out. Subjective assessment with structured pro forma was performed pre‐occlusal and post‐occlusal splint therapy. The objective measurement of the bilateral masseter muscle thickness was recorded using real‐time ultrasonography before and after splint therapy. Results: The mean ultrasound thickness of the masseter muscle in the pre‐clenching state before splint therapy was 9.45 mm (SD 1.39), and the post‐clenching state was 13.15 mm (SD 2.23). After splint therapy, the mean thickness in the pre‐clenching state was 9.14 mm (SD 1.31), and the post‐clenching state was 12.78 mm (SD 2.23; P < 0.001). Conclusion: Ultrasonographic measurements of the masseter muscle in patients with temporomandibular joint disc displacement with reduction can be a useful tool to assess the effectiveness of occlusal splint therapy. Such conservative measures can significantly reduce masticatory muscle tenderness, especially of the temporalis and masseter.     

Sex differences in pharyngeal airway morphology in adults with skeletal Class III malocclusion

Objectives: To compare the pharyngeal airway dimensions in adults with skeletal Class III malocclusion and well-balanced faces, to ascertain whether sex can influence such measurements and to correlate skeletal pattern with pharyngeal dimensions.

Methodology: Fifty adults were recruited and assigned to two groups: skeletal Class III (n = 25; 12 males and 13 females, mean age = 26.1 years), and skeletal Class I (n = 25; 11 males and 14 females, mean age = 26.0 years), with well-balanced faces. Pharyngeal measurements were made using cone beam computed tomography and analyzed with Dolphin Imaging software 11.5.

Results: Pharyngeal sagittal area, length, retroglossal area and width were statistically greater for males. Pharyngeal volume was greater for Class III patients (p = .0245), due to enlarged male dimensions. A significant but moderate correlation was observed between pharyngeal airway volume and ANB angle (r = ?.4917) and effective mandibular length (Co-Gn, r = .5181).

Conclusion: There is sexual differentiation in the pharyngeal airway morphology for Class III adults. As females present similar pharynx volume compared to a normal skeletal pattern, mandibular setback surgery should be carefully planned because of the risk of airway constriction.     

Clinical significance of T2 mapping MRI for the evaluation of masseter muscle pain in patients with temporomandibular joint disorders

Objectives

Masticatory muscle pain is one of the typical symptoms of temporomandibular joint disorders (TMD). T2 mapping (distribution of T2 values) is a notable MRI technique for evaluating water contents in tissues. We investigated the clinical significance of T2 mapping for the evaluation of masticator muscle conditions by comparing the difference in the T2 values between the painful and pain-free sides of the masseter muscle in patients with TMD.

Methods

Seventy-three patients clinically diagnosed with TMD were enrolled in this study. We divided the patients into two groups: a unilateral pain group (patients with unilateral masseter muscle pain) and a painless group (patients without muscle pain). There were 29 patients in the unilateral pain group and 44 patients in the painless group. We compared the difference in the mean T2 values between the painful and pain-free sides of the masseter muscle in the unilateral pain group and between the right and left sides in the painless group.

Results

The mean T2 values of the masseter muscle on the painful side were significantly higher than those on the pain-free side in the unilateral muscle pain group (p < 0.01). In the painless group, there was no significant difference in the mean T2 values between the right and left sides.

Conclusions

It is suggested that T2 mapping is a promising method for evaluating masseter muscle pain caused by edematous change related to TMD through monitoring of the T2 values.     

The relationship between neck pain and cervical alignment in patients with temporomandibular disorders

ABSTRACT

Objective: To elucidate the impact of neck pain on cervical alignment in patients with TMDs.

Method: Patients diagnosed with TMDs between November 2013 and November 2015 were included. All subjects underwent lateral cervical X-ray evaluation and completed the RDC/TMD Axis II Biobehavioral Questionnaire for TMDs. Patients with neck pain also completed the Neck Pain & Disability Scale (NPDS). Cervical lordosis angle was measured according to C2-C7 Cobb’s method.

Results: The mean cervical lordosis angle of the whole group (n = 60) revealed hypolordosis (10.9 ± 12.7°). Cervical lordosis angle did not differ between patients with (n = 28) and without (n = 32) neck pain (12.2 ± 12.8° versus 9.8 ± 12.7°, respectively; p = 0.46). TMD-related variables were not correlated with cervical alignment but were moderately correlated with NPDS score, with the exception of TMD-associated disability.

Conclusion: Patients with TMDs have hypolordotic cervical malalignment (tendency toward kyphosis) regardless of neck pain.     

Oxygen saturation and electromyographic changes in masseter muscle during experimental chewing of gum with harder texture

Abstract

Objective. The purpose of this study was to clarify the relationship between changes in masseter muscle oxygenation measured by near-infrared spectroscopy (NIRS) and changes in the electromyographic (EMG) power spectrum during experimental chewing of gum with harder texture, to improve the understanding of the use of NIRS in assessing masseter muscle fatigue. Material and methods. Ten female volunteers with normal occlusion were examined. Mean age (standard deviation) was 28.4 (3.8) years. Mean fracture stress of gum was 12.5 × 10⁴ N/m². Subjects were instructed to chew gum for 60 s (75 strokes) on the voluntary chewing side at a pace of 1.25 strokes/s. Simultaneous recordings of NIRS and EMG signals from masseter muscle were performed during gum chewing. Results. Oxygen saturation levels decreased from the start of chewing, then stabilized with a break point between the two phases. The normalized EMG amplitude increased and the mean frequency of the EMG power spectrum decreased during gum chewing. The timing of break point appearance was related to the timing of a significant decrease in median frequency, but no clear relationships were found between break point appearance and increased EMG amplitude. Conclusions. These results suggest that the break point of the oxygen saturation curve, as obtained from NIRS measurements, could be used as an indicator of masseter muscle fatigue as assessed by a shift in the EMG power spectrum to lower frequencies.     

Comparison of three different options for immediate treatment of painful temporomandibular disorders: a randomized,controlled pilot trial

Objective: The purpose of this study was to compare the short-term effectiveness of three different types of immediate, non-pharmacological intervention for alleviation of the painful symptoms of temporomandibular disorders (TMD).

Material and methods: Thirty-six patients (mean age 41.6?±?16.7 years, 25 females) diagnosed with non-dysfunctional painful TMD received counselling and subsequently were randomly allocated to three treatment groups: patients in Group A received prefabricated oral splints with water-filled elastic pads (Aqualizer^®), those in Group B were provided with vacuum-formed co-polyester oral splints and those in Group C were given appointments to receive Michigan-type hard splints. Clinical examination was conducted, at baseline and after 2 weeks, by use of the RDC/TMD. Current pain intensity was determined by evaluation of graded chronic pain status (GCPS) on a numerical rating scale (NRS). Active maximum mouth opening without pain (AMMOP) was also measured. Paired sample t-tests and one-way analysis of variance with a significance level of p?≤?0.05 were conducted.

Results: After 2 weeks, overall mean current pain was reduced by 41.95% (p?p?p?=?0.56) and C (22.29%, p?=?0.26). After 2 weeks, current pain level for Group B was significantly lower than that for Group C (p?=?0.041). Overall, there was a statistically significant increase of AMMOP (p?=?0.01).

Conclusion: All therapeutic options were pain-reducing. The results from this study suggest that cost-effective and time-effective intervention of counselling combined with use of a vacuum-formed splint is a favourable option for initial, short-term treatment of painful TMD.     

Impact of sleep bruxism on masseter and temporalis muscles and bite force

Objectives: This study aimed to analyze the impact of sleep bruxism (SB) on electromyography (EMG) activity and the thickness of the masseter and temporal and maximal molar bite force. Method: Ninety individuals, aged between 18 and 45 years, were selected and divided into two groups: Group I (case group, 45 individuals with SB) and Group II (control group, 45 individuals without SB). A diagnosis of SB was made from polysomnography. Results: The data obtained from EMG and the muscle thickness and the maximal molar bite force were tabulated (SPSS 21.0), normalized, and subjected to statistical analysis (p ≤ 0.05). Comparisons between the groups showed significant differences regarding the habitual chewing of hard food for the left temporalis muscle (p = 0.04) and the chewing of soft food for the right masseter muscle (p = 0.04), but no significant differences for the measurements of muscle thickness and maximal molar bite force. Discussion: The present data suggest that SB negatively altered the masticatory muscles’ functions. Based on the results of this research, it can be concluded that individuals with SB showed decreased EMG activity in the masticatory muscles.     

The effects of stabilization splint treatment on the volume of masseter muscle in sleep bruxism patients

Objective: The aim of this study was to evaluate, quantitatively, the volumetric effects of stabilization splint therapy on the masseter muscle of sleep bruxism (SB) patients.

Methods: The magnetic resonance (MR) images of 16 SB patients diagnosed by polysomnography (PSG) who used stabilization splints for four months were obtained before and after the therapy. The masseter muscle volume was calculated using Cavalieri’s principle on the MR images.

Results: After the splint therapy, the mean volume of the masseter muscle did not reduce significantly. The fat and/or water content of the muscles did not change either.

Discussion: The stabilization splint therapy had no effect on the volume, fat and/or water content of the masseter muscle; however the discomfort was reduced in the patients. Although the effect of splint therapy is not fully understood, the non-invasive and reversible stabilization splint can be used in SB patients because of its relaxation effect on muscles.     

Average chewing pattern improvements following Disclusion Time reduction

Objectives: Studies involving electrognathographic (EGN) recordings of chewing improvements obtained following occlusal adjustment therapy are rare, as most studies lack ‘chewing’ within the research. The objectives of this study were to determine if reducing long Disclusion Time to short Disclusion Time with the immediate complete anterior guidance development (ICAGD) coronoplasty in symptomatic subjects altered their average chewing pattern (ACP) and their muscle function.

Methods: Twenty-nine muscularly symptomatic subjects underwent simultaneous EMG and EGN recordings of right and left gum chewing, before and after the ICAGD coronoplasty. Statistical differences in the mean Disclusion Time, the mean muscle contraction cycle, and the mean ACP resultant from ICAGD underwent the Student’s paired t-test (α = 0.05).

Results: Disclusion Time reductions from ICAGD were significant (2.11–0.45 s. p = 0.0000). Post-ICAGD muscle changes were significant in the mean area (p = 0.000001), the peak amplitude (p = 0.00005), the time to peak contraction (p < 0.000004), the time to 50% peak contraction (p < 0.00001), and in the decreased number of silent periods per side (right p < 0.0000002; left p < 0.0000006). Post-ICAGD ACP changes were also significant; the terminal chewing position became closer to centric occlusion (p < 0.002), the maximum and average chewing velocities increased (p < 0.002; p < 0.00005), the opening and closing times, the cycle time, and the occlusal contact time all decreased (p < 0.004–0.0001).

Conclusion: The average chewing pattern (ACP) shape, speed, consistency, muscular coordination, and vertical opening improvements can be significantly improved in muscularly dysfunctional TMD patients within one week’s time of undergoing the ICAGD enameloplasty. Computer-measured and guided occlusal adjustments quickly and physiologically improved chewing, without requiring the patients to wear pre- or post-treatment appliances.     

Relationship between depression and masticatory muscles function in a group of adolescents

Objective: The aim of the study is to determine association between depressive symptoms and the electrical activity of muscles in maximum voluntary clench in a group of young adults.

Methods: A total of 186 volunteers (Females = 98, Males = 88), with a mean age of 19 years, were recruited to the study. All participants took a questionnaire survey stating the level of depression (Beck’s scale), clinical examination, and instrumental diagnostics (EMG).

Results: Symptoms of mild or medium depression were found in 35 of the subjects (18.82%). Average electric potentials of the masticatory muscles in maximal voluntary clench were significantly higher among the subjects with depression symptoms in comparison with subjects without those symptoms (85.96 ± 10.25 vs 78.97 ± 15.32, p < . 0.05).

Discussion: An increase in the electrical potentials of masseter muscles in maximal voluntary clench was found in the group with depression symptoms. The study should be continued to confirm this finding.     

Temporomandibular disorders and mandibular vertical asymmetry

Objective To analyze the association between mandibular vertical asymmetry and the presence of TMD in adult patients.

Methods This case-control study recruited patients from the orthodontic clinic at FEBUAP. Patients were classified on the basis of diagnostic criteria for temporomandibular disorders (DC/TMD). Panoramic radiographs were measured to determine mandibular vertical asymmetry indices according to criteria described by Kjellberg and Habets. Both methods (DC/TMD and index criteria) were standardized a priori.

Results A total of 56 patients were analyzed, of whom 25 (44.6%) met the inclusion criteria and were divided into two groups (TMD group, n = 15; non-TMD group, n = 10). The highest asymmetry index was observed in the condylar neck, followed by the total condylar asymmetry index, but without significant differences between groups (p > .05).

Conclusion There is no association (p > .05) between temporomandibular disorders and mandibular vertical asymmetry.     

The potential etiologic factors influencing tinnitus intensity in patients with temporomandibular disorders

Objectives: To investigate the potential relationships between the intensity of tinnitus associated with temporomandibular disorders (TMD) and potential etiologic factors, including age, gender, freeway space, sleep bruxism (SB), joint clicking, and headache.

Methods: The sample was comprised of 90 patients without any hearing loss, as confirmed by otorhinolaryngology, who self-reported subjective tinnitus and simultaneous TMD, based on the Research Diagnostic Criteria for TMD (RDC/TMD).

Results: The results showed a positive, weak correlation between the intensity of tinnitus and age (r = 0.225, p = 0.033). The presence of SB and headache were seen in higher proportions in the present sample, at 75.5% (n = 68) and 66.6% (n = 60), respectively.

Conclusions: In a population of patients with subjective tinnitus and TMD, no significant associations were found between tinnitus intensity and age, freeway space, SB, clicking presence, and headache, though gender did show a weak correlation with tinnitus intensity.     

A comparison trial between three treatment modalities for the management of myofascial pain of jaw muscles: A preliminary study

Objectives: To compare three treatment modalities for the management of myofascial pain of jaw muscles.

Methods: Thirty (N = 30) patients with low pain-related impairment were randomly assigned to receive laser therapy (LST), oral appliance therapy (OA), or counseling (CSL). Visual Analog Scale (VAS) pain levels and the Muscular Index (MI) of the Craniomandibular Index were the outcome variables, which were assessed at baseline, at three weeks, three months, and six months.

Results: At six months, improvement in the MI was maintained both in the LST (p = .025) and OA groups (p < .001). As for VAS values, positive changes were still shown for LST (p = .001), and were also shown for the OA (p = .002) and CSL groups (p = .048).

Conclusions: Despite differences in the short-term effectiveness of LST and OA, with respect to CSL alone, all three treatment groups improved at six months. This suggests that active treatments should be directed to maximize the positive changes in the short-term period.     

Relations between the results of complex clinical and neurophysiological examinations in patients with temporomandibular disorders symptoms

Objective: Reinvestigation of clinical importance of surface electromyography recordings (sEMG) from the masticatory, neck and shoulder girdle muscles in patients with various clinically detected temporomandibular disorders (TMDs).

Methods: Fifty women with myalgia diagnosis of Axis I DC/TMD and the same number of healthy female volunteers were studied clinically and neurophysiologically by means of sEMG.

Results: Unilateral more than bilateral complex symptoms of TMDs were related to the non-neurogenic masticatory rather than neck and shoulder girdle muscles dysfunctions at rest. A strong negative correlation between masticatory muscles activity at rest and during maximal contraction was found (r_s = ?0.778), mainly in the masseter muscle.

Conclusion: sEMG is a suitable tool for prosthodontists because it provides objective results on the stomatognathic system muscles function. Pain and other temporomandibular symptoms detected mostly unilaterally significantly increase muscle tension of the masticatory muscles and diminish muscle motor units recruitment during maximal contraction. Effects may spread to the neck and shoulder girdle muscles.     

Effects of neuromuscular deprogramming on the head position

Objectives:

The aim of this study was to evaluate the effects of the neuromuscular deprogramming of the mandible on the craniocervical position.

Methods:

Participants (n?=?65) were separated into two groups: 25 untreated controls (10 men and 15 women) and 40 patients (17 men and 23 women) and underwent neuromuscular deprogramming with upper occlusal splints for an average of 6 months and 7 days, before orthodontic treatment. Lateral cephalograms were obtained from each subject in the natural head position (NHP), before and after neuromuscular deprogramming. Craniocervical cephalometric analysis was performed to evaluate craniovertical (NSL/VER), craniocervical (OPT/NSL and CVT/NSL), and cervicohorizontal (OPT/HOR and CVT/HOR) angulation, and the angle of the cervical curvature (OPT/CVT).

Results:

After neuromuscular deprogramming, significant changes in three angles — NSL/VER (P<0·001), OPT/NSL (P<0·001) and CVT/NSL (P<0·001) — were found between the two groups. For the cervical spine position, no significant changes were observed.

Conclusion:

The results indicate that neuromuscular deprogramming using occlusal splint causes significant extension of the head.     

Arthrocentesis with different irrigation volumes in patients with disc displacement without reduction: One-year follow-up

ABSTRACT

Objective: This study evaluated the clinical efficacy of arthrocentesis when varying the irrigation volume in patients with disc displacement without reduction (DDWOR).

Methods: Thirty DDWOR patients were equally divided into two groups: G1 (50 mL) and G2 (200 mL). Information was compared for pain, the maximum interincisal distance (MID), protrusion, and right and left laterality.

Results: Arthrocentesis was able to reduce the pain and increase the MID, protrusion, and both laterality values significantly one year after the procedure (p < 0.001) in both groups. However, comparisons between the groups revealed no significant difference (p > 0.05). Furthermore, changes in volume did not affect the arthrocentesis results (p = 0.626, odds ratio = 1.625; 95% confidence interval = 0.230–11.461).

Conclusion: Arthrocentesis techniques using 50- and 200-mL irrigation volumes were both effective, with no significant differences between techniques observed after one year of follow-up.