Effectiveness of Splint Therapy in the Management of Temporomandibular Joint Disorders

Keywords

Bruxism; Crepitus; Joint Pain; Temporomandibular Joint Disorders; Occlusal Splints; Trismus; MPDS; Clicking; Internal Derangement.

Introduction

Temporomandibular joint disorders (TMD) and its relationship to dentistry has been an important topic in recent years. Costen was the first to describe the temporomandibular joint (TMJ) condition in 1934. TMD was defined by the American Dental Association President's Conference on Temporomandibular Disorders (American Dental Association, 1983) as a set of orofacial disorders characterized by discomfort in the preauricular area, TMJ, or masticatory muscles, and a limitation in chewing ability [1].

TMD is a group of diseases characterized by discomfort in the TMJ or surrounding tissues, mandibular functional restrictions, or clicking in the TMJ during motion [2]. Temporomandibular dysfunction syndrome, pain dysfunction syndrome, facial arthromyalgia, TMJ dysfunction syndrome, and myofascial pain dysfunction are some of the terms used to describe conditions that cause pain and malfunction in the TMJ [3]. TMD is a frequent illness that affects people between the ages of 20 and 40 [4]. TMDs are a set of clinical diseases that involve the temporomandibular joint (TMJ), myofascial muscles, and other related tissues [5]. There is currently no single standard for the classification of TMD, although the most widely used criteria are the research diagnostic criteria for temporomandibular disorders (RDC/TMD).TMJ pain and clicking, myofascial or oral masticatory muscle pain, and irregular jaw movement are the most common indications and symptoms [6]. TMD is a major public health issue since it is a leading cause of persistent oral and facial pain that interferes with daily activities [7, 8]. Other symptoms affecting the head and neck region, such as headache and ear-related problems, are frequently connected with these illnesses.Approximately, 33% of the population has at least one TMD symptom, and 3.7% to 7% of the population has TMD that is severe enough to demand treatment [9]. TMJ issues have an unknown origin, however it is likely complex.Abnormal occlusion, parafunctional habits (e.g., bruxism [teeth grinding], teeth clenching, lip biting), stress, anxiety, or anomalies of the intra-articular disc can induce capsule inflammation or destruction, as well as muscle discomfort or spasm [9, 10]. People with and without TMJ symptoms both appear to have abnormal oral occlusion. TMJ microtrauma is hypothesized to be caused by non-functional habits [9-11].

Notably, whereas 60-70 percent of the general population has indicators of TMD, only around one-fourth of those who have indications are aware of any symptoms. Occlusal anomalies, psychological stress, orthodontic treatment, microtrauma, poor health and nutrition, joint laxity, and exogenous estrogen are some of the contributing factors to TMD [12]. Occlusal therapy, psychotherapy, physical therapy, medication, manual therapy, and surgery are the most common treatments for TMD. In practice, an occlusal splint is a removable appliance made of resin that is designed to cover all of the occlusal and incisal surfaces of the upper and lower jaw's teeth.Because of its ease of use, low cost, and broad indications, occlusal splint therapy is the most often utilized clinical method [6, 12]. A prior meta-analysis looked at the efficacy of splint therapy for TMD, but why it works is still unknown. To learn more about the clinical success of splint therapy in the treatment of TMD in adults a meta-analysis was conducted which compared the clinical effects reported in all relevant randomized controlled trials to determine the functional features of splint therapy (RCTs) [13]. Splints can be used to treat or control TMD in a variety of ways which includesthe stabilization splint, soft splint, flat splint, and pivot splint. Although the mechanisms of splint action are unknown, it was discovered that TMD patients treated with an occlusal splint had higher plasma levels of calcitonin gene related peptide (CGRP)[4, 13].

Medication, habit change, psychotherapy, physical therapy, splint therapy, and manipulation are examples of conservative treatments. Patients utilize medications like ketorolac and paracetamol for transient relief because of their effectiveness. Arthrocentesis, arthroscopy, arthroplasty, discectomy, and temporomandibular joint (TMJ) reconstruction are some of the surgical options. Patient with TMJ dysfunction who have orthognathic surgery are likely to have markedly better signs and symptoms after surgery [10]. Orthognathic surgery involves movement of the jaws in all three planes. It has been found that temporomandibular joint diseases can emerge as a result of maxillofacial trauma or road traffic incidents that directly or indirectly damage the TMJ. Oral splints (OS), also known as occlusal splints, are removable occlusal devices that are used to diagnose TMDs and treat the dysfunction of the mandible-maxilla relationship [10, 14, 15]. The initial choice for TMJ treatment is usually recognized to be a conservative, reversible approach. Oral splints are widely used for internal derangement and as one of the conservative therapies. Wearing anocclusal splint is thought to generate changes in mechanical sensitive input emerging from periodontal tissue and spindle afferents in the jaw closing muscle, as well as a decrease in intra-articular pressure in the TMJ, according to the mechanisms of occlusal splint therapy [16]. The occlusal splint is frequently effective, but the time it takes to achieve a pain-free normal range of motion is insufficient. Although dental splints are sometimes used to stabilize the occlusion or prevent dentition wear, one of the most prevalent uses in the treatment of TMDs is to protect the TMJ discs from dysfunctional stresses that can cause perforations or displacements [17].

Previous research has emphasized the relevance of conservative splint therapy in the treatment of TMD discomfort. While the investigation is being carried out, however, a number of difficulties are reported. Conservative splint therapy, according to Lee, Hye- Sung, et al, is extremely successful, however it does not always result in a good outcome [18]. In such circumstances, a surgical procedure should be explored. Some studies illustrate the necessity and need of splint therapy however, it takes a longer period of action to achieve a pain-free condition, and obtain patient compliance. Splint therapy is only effective in minor cases and cannot be used to treat complex TMD symptoms [19]. These appliances are frequently used in conjunction with other treatments like physiotherapy or medicines.

The goal of this study was to determine the effectiveness of splint therapy in patients with temporomandibular joint disorders and its association based on age and gender of the patients. The effectiveness of splint therapy in patients suffering from various temporomandibular joint disorders is assessed based on reduction in pain, discomfort and parafunctional habits, increased maximal mouth opening and improved quality of life.

Materials And Methods

Study design and Study setting

This retrospective study was conducted in Saveetha dental college and hospital, Saveetha university, Chennai, to assess the effectiveness of splint therapy in the management of temporomandibular joint disorders among dental patients reporting from June 2019 to December 2020. The study was initiated after approval from the institutional review board andit was covered by the following ethical approval number; SDC/SIHEC/2020/DIASDATA/ 0619-0320.

Study population and sampling

Inclusion criteria for the study were adult dental patients with TMD. Exclusion criteria included immunocompromised patients, dental anomalies, systemic diseases with cognitive problems and speech problems, missing or incomplete data. After assessment in the university patient data registry, consecutive case records of 192 patients who were diagnosed with TMD and underwent splint therapy were included in the study. Cross verification of data for errors was done with the help of an external examiner.

Data collection and tabulation

Data regarding patients having TMD were retrieved after analysing 86000 case sheets. The following parameters were evaluated based on the dental records; age, gender, types of TMD, types of splint therapy for TMD. Chief complaints, medical and dental history,all the clinical manifestations of TMDs, treatment strategies andoutcomes of the patients with the splint therapy [effectiveness or ineffectiveness] were examined from the data, collected and recorded. Patients diagnosed with TMD were further classified into disc-condyle disorder [TMJ internal derangement, TMJ dislocation/subluxation], degenerative disorder and myofascial pain and dysfunction syndrome (MPDS). The clinical presentations of TMD were considered into several variables and the patients were classified according to the severity of the TMD for diagnosis, treatment and prognosis purposes. Data was entered in excel and was imported to SPSS. The variables were defined.

Statistical Analysis

The collected data was validated, tabulated and analysed with Statistical Package for Social Sciences for Windows, version 23.0 (SPSS Inc., Chicago, IL, USA) and results were obtained. Descriptive analysis was used to describe the number of patients treated with splint therapy based on age, gender, types of TMD, types of splint therapy and effectiveness of the splint therapy among the study population. Categorical variables were expressed in frequency and percentage; and continuous variables in mean and standard deviation. Chi-square test was used to test associations between categorical variables (age, gender, types of TMD, types of splint therapy, and effectiveness of splint therapy for treating temporomandibular joint disorders). P value < 0.05 was considered statistically significant.

Results

In our study, a total of 192 patients with TMD undergoing splint therapy were assessed with the age range of 10-60 years and mean age of 21-40 years. The age group of 21-30 years had higher rate of splint therapy (37.82%) followed by 31-40 years age group with 32.12% [Figure 1]. Male patients were predominantly on splint therapy (54.9%) than the females (45.08%) [Figure 2]. Splint therapy was predominantly provided for disc-condyle disorder patients followed by MPDS condition and least for the patients with degenerative disorders [Figure 3]. Soft splint was predominantly (89.2%) chosen for patients with TMD with only 10.8% patients were provided with hard splint as it was required [Figure 4]. Splint therapy was effective for majority of the patients (80%) with TMD [Figure 5].

The association between age and gender of patients with the effectiveness of splint therapy for treating temporomandibular joint disorders was statistically significant. Effectiveness of splint therapy was higher in age group 21-30 years (34.72%), and it was (slightly) ineffective in 8.81% of patients in the age group of 31- 40 years [Figure 6]. Splint therapy was effective for both females and males with 35.75% and 43.52% respectively with a higher rate for males [Figure 7]. The association between type of splint therapy and effectiveness of splint therapy for treating temporomandibular joint disorders was statistically significant. Soft splints were more effective (70.98%) than the hard splints (8.29%) [Figure 8]. The association between type of temporomandibular joint disorder and effectiveness of splint therapy for treatingtemporomandibular joint disorders was statistically significant. Splint therapy was effective in 45% of patients with disc-condyle disorder and in 26.7% of patients with MPDS. It was not very useful in patient with degenerative disorders as it was effective in only 7.33% of patients [Figure 9].

×

Figure 1:

Close

Figure 1. Bar chart showing gender wise distribution of our study population with predominance of female gender. X axis represents the gender and Y axis represents the percentage of patients in our study.

×

Figure 2:

Close

Figure 2. Bar chart showing age wise distribution of our study population. X axis represents the age category and y axis represents the percentage of patients in our study. It is seen most of the patients in our study belong to 10-19 years followed by 30-39 years.

×

Figure 3:

Close

Figure 3. Bar chart showing distribution of dental occlusion in our study population. X axis represents the type of occlusion and the y axis represents the percentage of patients in our study. Class 1 malocclusion was the most predominant occlusion present among the study population.

×

Figure 4:

Close

Figure 4. Bar chart shows the association between temporomandibular joint disorders and the type of occlusion. X axis represents the presence or absence of TMD and the y axis represents the number of patients with different types of malocclusion. Chi- square analysis was done and the association was found to be statistically significant. Pearson chi-square value-19.243; DF-2, p-value <0.001. This shows that the patients with class 1 malocclusion are the most associated with TMD, this association is statistically significant.

×

Figure 5:

Close

Figure 5. Bar chart showing gender wise distribution of our study population with predominance of female gender. X axis represents the gender and Y axis represents the percentage of patients in our study.

×

Figure 6:

Close

Figure 6. Bar chart showing age wise distribution of our study population. X axis represents the age category and y axis represents the percentage of patients in our study. It is seen most of the patients in our study belong to 10-19 years followed by 30-39 years.

×

Figure 7:

Close

Figure 7. Bar chart showing distribution of dental occlusion in our study population. X axis represents the type of occlusion and the y axis represents the percentage of patients in our study. Class 1 malocclusion was the most predominant occlusion present among the study population.

×

Figure 8:

Close

Figure 8. Bar chart shows the association between temporomandibular joint disorders and the type of occlusion. X axis represents the presence or absence of TMD and the y axis represents the number of patients with different types of malocclusion. Chi- square analysis was done and the association was found to be statistically significant. Pearson chi-square value-19.243; DF-2, p-value <0.001. This shows that the patients with class 1 malocclusion are the most associated with TMD, this association is statistically significant.

×

Figure 9:

Close

Figure 9. Bar chart shows the association between temporomandibular joint disorders and the type of occlusion. X axis represents the presence or absence of TMD and the y axis represents the number of patients with different types of malocclusion. Chi- square analysis was done and the association was found to be statistically significant. Pearson chi-square value-19.243; DF-2, p-value <0.001. This shows that the patients with class 1 malocclusion are the most associated with TMD, this association is statistically significant.

Discussion

TMJ disorders are now evolving commonly among the younger population. Disc-condyle disorders occurs more commonly than the other types of TMD.According to our study, the mean age of participants undergoing splint therapy was between 21-40 years. Similarlyin a study by Wassell et al, patients reporting temporomandibular joint disease were aged 18 and above, with a mean age of 30.2 years [20]. The average age of individuals reporting with TMD and for conservative management was 22.59 years in another study by Lee HS et al [18]. Thus, most of the studies show that the age range most affected by TMD is from 18 to 65 years of age. In a study on TMD, 45 of the 76 patients were males and 31 were females [3]. Similarlymale patients were predominantly on splint therapy (54.9%) than the females (45.08%) in our study. Lee HS., et al. in their study found that out of 43 cases, thirty were men and forty were women, contradicting our findings [18]. This difference in male to female ratio among the studies could be due to the variations in the small sample size and demographics.

Because most TMD symptoms remit quickly, usually within 2–4 weeks, conservative treatment is deemed more appropriate than surgery for these conditions [21]. Soft splints have certain advantages as a conservative treatment for TMDs, such as their relative simplicity, reversibility, noninvasiveness, and low cost.These splints can be customized to fit either the maxillary or mandibular arch, and they can be usually used immediately. Soft splints easily disperse the severe loads experienced during parafunctional activities due to their soft and robust material properties, and they have been linked to a high level of patient tolerance. Hard splints, on the other hand, were reported to be effective in individuals with masticatory system problems. It was also saidthat both soft and hard occlusal appliances are equally effective in reducing masticatory muscle pain in the short term [19, 21]. In light of these disagreements, the current investigation was done to compare the efficiency of splint therapy (soft versus hard occlusal splint therapies) for the management of TMDs.

According to our study, soft splint was predominantly (89.2%) chosen for patients with TMD with only 10.8% patients were provided with hard splint as it was required.Soft splints were more effective (70.98%) than the hard splints (8.29%) in reducing pain and discomfort due to TMD among the patients. Splint therapy was predominantly provided for disc-condyle disorder patients followed by MPDS condition and least for the patients with degenerative disorders. In our study, splint therapy was effective in majority of the patients (80%) with TMD. A study demonstrated thatafter splint therapy, 87 percent of patients reported less discomfort, 50% reported lower VAS scores, and 70% reported no clicking [22]. Soft splint therapy reduced facial myalgia and TMJ clicking by 74% in another trial [23]. The uniform intensity of interactions among all teeth, together with disocclusion of the front teeth, accounted for these advantages and both hard and soft occlusal splint therapies were effective in the treatment of TMD, while soft splint therapy improved some TMD symptoms more quickly [23].

Splint therapy for TMD symptoms was thought to be effective for at least three months. Our patients had pain relief immediately after splint therapy and it was effective for a period of 12 months. In accordance to other studies [22, 23], we recommend the utility of splint therapy to treat MPDS and TMDs in individuals with anterior disc displacement and reduction.In a similar study it was found that more than half of the patients experienced total pain relief after splint therapy [24]. In another study, wearing an occlusal splint reduced TMJ pain by about 70% and muscle discomfort related with increased muscular activity by about 85.2 percent [25]. A study reported that at six weeks, 17 out of 36 patients had pain reductions of less than 50%. The pain for a few participants did not subside immediately, and it took up to 6 to 12 months for them to be completely pain-free [26]. In another study, 12 patients were pain-free due to splint therapy in group 1, 5 patients were pain-free post physical therapy in group 2, and 9 patients were pain-free post physical therapy in addition to splint therapy in group 3. Splint therapy was found to be the most effective treatment approach for reducing pain and discomfort associated with TMD when compared to the other two treatments evaluated, as 12 out of 20 patients were pain-free [27].

The implantation of an occlusal splint changes the resting posture, and adjusting to this new position expands the occlusal vertical dimension beyond the open space [28]. The modified resting position improves muscle efficiency during contact and lowers muscle activity during postural duties. Meanwhile, when the vertical dimension increases, the muscular effort required reduces, resulting in reversibility. Different authors evaluated the use of a soft occlusal splint with muscle relaxants and analgesics in the treatment of MPDS, and found that occlusal splint therapy improved pain, muscle soreness, and TMJ clicking more than pharmaceutical treatment [29]. Researchers indicated that occlusal splint therapy for MPDS is effective based on data from electromyography of the masticatory muscles [29, 30]. Our findings back up their findings, demonstrating that occlusal splint therapy is a safe and effective therapeutic option for lowering pain and muscle tenderness while also enhancing jaw opening.

Previously our team had conducted numerous clinical trials [31- 36], and systematic reviews [37-39] regarding TMD over the past 5 years.Now we are focussing on studies to evaluate the effectiveness of various treatment modalitiesfor TMD. Limitations of the study include small sample size and a small population covered. Larger samples could be collected and analyzed over a longer time period. Future scope of this study would be to conduct a multicentric trial among diverse population.

Conclusion

In our study, an increased number of people in the younger age, especially males received the splint therapy for the management of temporomandibular joint disorders. Soft splints were chosen for the vast majority of the people which were very effective in treating temporomandibular joint disorders. Splint therapy was very effective in treating younger age people than the elderly. Splint therapy was effective for both females and males with males exhibiting a higher response rate. Splint therapy was very effective in treating patients with disc-condyle disorder followed by MPDS patients. The association between the age and gender of the patients, types of TMD and types of splint therapy with the effectiveness of splint therapy for treating temporomandibular joint disorders were statistically significant. In our study, majority of the patients with TMJ pain responded well to splint therapy, but a small a percentage of patients developed refractory or persistent TMD.