Physiological effects of anterior repositioning splint on temporomandibular joint disc displacement: a quantitative analysis

Physical therapy and non-surgical manual disc reduction combined with anterior repositioning splint for acute disc displacement without reduction of the temporomandibular joint in adolescents

OBJECTIVES

Current studies on the treatment of adolescent patients with disc displacement without reduction (DDWOR) are limited by short follow-up periods and small sample sizes, and there are few comparative studies on the efficacy of conservative treatment with and without disc reduction for acute DDWOR. This study compared the therapeutic effects of two conservative treatment methods: physical therapy alone and physical therapy combined with non-surgical manual disc reduction and anterior repositioning splints (ARS), in adolescent patients with acute DDWOR.

MATERIALS AND METHODS

This retrospective study included adolescent patients with DDWOR who underwent physical therapy at the Temporomandibular Joint Rehabilitation Department of the Shanghai Ninth People's Hospital from January 2018 to December 2021. Patient assessment data were collected before and after treatment. Patients were followed up through telephone and online questionnaires from March to August 2023.

RESULTS

The results indicate that compared to physical therapy alone, the combination of physical therapy and non-surgical manual disc reduction with ARS showed better short-term efficacy, improved mouth opening, and better long-term pain control. Also, it may be effective in preventing degenerative joint disease.

CONCLUSIONS

This combination therapy is recommended for clinical application in adolescent patients with acute DDWOR.

CLINICAL RELEVANCE

The present research demonstrates the superior efficacy of physical therapy and non-surgical manual disc reduction combined with anterior repositioning splint in adolescent patients with acute DDWOR.

Clinical effect of digitalized designed and 3D-printed repositioning splints in the treatment of anterior displacement of temporomandibular joint disc

OBJECTIVE

To compare the treatment effectiveness of digitized and 3D-printed repositioning splints with that of conventional repositioning splints in the treatment of anterior displacement of the temporomandibular joint disc.

METHODS

This retrospective study included 96 patients with disc displacement of the anterior temporomandibular joint. They were treated with either digitally designed and 3D-printed repositioning splints or traditional splints and followed up for at least six months. Changes in signs and symptoms such as pain and mouth opening before and after treatment were recorded to evaluate treatment outcomes.

RESULTS

During the first month of treatment, both the digitally designed and 3D-printed repositioning splint groups (Group B) and the traditional repositioning splint group (Group A) showed significant increases in mouth opening, with increases of 4.93 ± 3.06 mm and 4.07 ± 4.69 mm, respectively, and there was no significant difference between the two groups. Both groups had a significant reduction in visual analog scale (VAS) pain scores, with Group B showing a greater reduction of 1.946 ± 1.113 compared to 1.488 ± 0.978 in Group A (P < 0.05). By the sixth month, Group B's mouth opening further improved to 38.65 ± 3.22 mm (P < 0.05), while Group A's mouth opening did not significantly improve. Regarding pain, Group A's VAS score decreased by 0.463 ± 0.778 after one month, and Group B's score decreased by 0.455 ± 0.715; both groups showed significant reductions, but there was no significant difference between the two groups.

CONCLUSION

Compared with traditional repositioning splints, digitally designed and 3D-printed repositioning splints are more effective at reducing patient pain and improving mouth opening. 3D-printed repositioning splints are an effective treatment method for temporomandibular joint disc displacement and have significant potential for widespread clinical application.

Investigation of the accuracy of dynamic condylar position: A model study

OBJECTIVES

To evaluate dynamic condylar positions by integrating mandibular movement recording data and cone-beam computed tomography (CBCT) and to investigate its accuracy via dynamic model experiments.

METHODS

A polyvinyl chloride skull model was utilized. A robot arm was used to operate the mandible to perform mouth opening, closing, protrusion, and lateral movements. A recording device, worn on the skull, was used to record the dynamic process and an optical position tracking (OPT) system was used to simultaneously trace the movements. A self-developed software module was used to evaluate the dynamic condylar position by integrating the dynamic tracing data and a virtual skull model derived from CBCT images. Errors were defined as differences between the dynamic coordinates of six landmarks around the condylar area derived from the software module (test) and OPT system (gold standard).

RESULTS

The condylar position errors were 0.76 ± 0.31, 0.55 ± 0.15, and 0.68 ± 0.23 mm for mouth opening, bilateral, and protrusion movements, respectively. Furthermore, the errors for small, moderate, and large mouth opening movements were 0.62 ± 0.19, 0.69 ± 0.29, and 0.94 ± 0.31 mm, respectively. The errors for all movements, except for large mouth opening, were significantly less than 1 mm (P < 0.05). The error was not different from 1 mm in the large mouth opening movement (P > 0.05).

CONCLUSIONS

Our developed method of achieving dynamic condylar position by integrating mandibular movement recording data and CBCT images is clinically reliable.

CLINICAL SIGNIFICANCE

This study proved the reliability of evaluating dynamic condylar position using a commercial dynamic recording instrument and CBCT images.

Step-back anterior repositioning splint retraction for temporomandibular joint disc displacement with reduction in adult patients

BACKGROUND

Anterior repositioning splint (ARS) is used to treat temporomandibular joint (TMJ) disc displacement with reduction (DDwR). However, high recurrence rate remains a problem especially in patients with unstable occlusions.

OBJECTIVE

This study optimised standard ARS therapy and proposed a step-back ARS retraction (SAR) method in adult patients with DDwR.

METHODS

Dental examinations and magnetic resonance imaging of TMJ were obtained before treatment (T0), 1 to 3 months (T1), 3 to 6 months (T2) and 6 to 12 months (T3) during treatment in 48 adults (average age 27.1 ± 5.7 years). After 3 months of basic ARS wearing, personalised treatment for patients with normal disc-condyle relationship was prescribed depending on bilaminar zone adaptations and severity of molar openbite. SAR which required sequential ARS wearing was designed for patients with deep overbite/overjet until retrodiscal tissue adaptations and stable occlusions were achieved.

RESULTS

The maximum interincisal opening was increased from 44.3 ± 6.9 to 45.3 ± 6.3 mm (p < .01), and joint pain was alleviated after ARS treatment. The overall success rate of ARS wearing was 92.1% (58/63) featured by a recaptured disc. Fifteen patients who underwent SAR therapy all showed bilaminar zone adaptations in the end, and one patient had positive condylar bone remodelling.

CONCLUSIONS

ARS treatment could improve mouth opening and joint symptoms in adult DDwR patients. SAR method was suitable for treating DDwR patients with deep overbite and overjet and improved retrodiscal tissue adaptations and condylar bone remodelling.

Assessing the Efficacy of Anterior Repositioning Splints in the Management of Temporomandibular Disc Displacement: A Systematic Review and Meta-Analysis

Disc displacement (DD) occurs when the cushioning disc of the temporomandibular joint (TMJ), situated between the jawbone and the skull, is out of position. The condition can be of two kinds: disc displacement with reduction (ddwr) and disc displacement without reduction (ddwor). The present systematic review was undertaken to assess the efficacy of anterior repositioning splints (ARS) for ddwr and ddwor. Three online databases were searched for relevant studies using MeSH keywords and Boolean operators. Initial searches of the databases extracted 552 records. Twelve studies equally representing ARS with ddwr and ddwor were selected. No clear difference could be assessed regarding ARS usage in both conditions. The outcome assessed was the improvement in TMJ symptoms. The results suggested that both ddwr and ddwor were effective in improving temporomandibular joint (TMJ) symptoms in patients who received ARS therapy. Efficacy levels ranged from 71-83% and 50-95% for ARS in ddwr and ddwor, respectively; odds ratio (OR) values ranging from 0.30 and 0.36 were obtained for ARS in both therapies, respectively, indicating similar performance levels. Both ddwr and ddwor respond well to the use of ARS; however, more clinical trials are needed to ascertain and validate the role of ARS as a treatment modality in this regard.

Biomechanics and Derangements of the Temporomandibular Joint

The human temporomandibular joint, is a ginglymo-arthrodial joint. The articular disk serves as a fibrous, viscoelastic structure that allows force distribution and smooth movement of the joint in its normal arrangement during mandibular movements. Most studies suggest that in the normal disk position the posterior band is located at the 12'o clock position within the glenoid fossa in the closed mouth posture. When the biomechanics of the joint is altered, the disk may be displaced creating an abnormal relationship between the disk, condyle, and the eminence that is often referred to as an internal derangement. This article reviews the various presentations of internal derangements.

Full-Digital Workflow for TMDs Management: A Case Series

Temporomandibular joint disorders (TMDs) have always been the subject of studies due to the difficult management of symptoms and the complex stabilization of the so-called therapeutic position. In this effort, digital technologies open new opportunities for such planning, allowing the clinician to digitally assess the situation and verify the stability of the new position from a functional point of view. The present case series shows examples of preliminary full-digital planning of treatment in TMDs patients made with the preliminary evaluation of the kinematic activity of the mandible through a digital device (Tech in motion™, ModJaw, Villeurbanne, France). Three TMD clinical cases are analyzed with full-digital techniques and workflow. A personalized treatment for each case was digitally planned on the base of proper kinematic tracings recorded for each patient, and intraoral appliances were digitally customized through a full-digital or semi-digital workflow. The digitalization of mandibular kinematic gave us the possibility of making a more “aware” diagnosis, especially in a dynamic key, and then it allowed a faster realization and execution of the intraoral appliance through a digital workflow, memorizing the therapeutic position and early checking the device, before its realization, on the real kinematics of the patient.

Disc-condyle relationship alterations following stabilization splint therapy or arthrocentesis plus hyaluronic acid injection in patients with anterior disc displacement: a retrospective cohort study

OBJECTIVE

The objective of this study was to quantitatively evaluate the efficacy of stabilization splint (SS) therapy or arthrocentesis plus hyaluronic acid (HA) injection in the treatment of anterior disc displacement (ADD) through magnetic resonance imaging (MRI).

METHODS

99 subjects were collected in this study. 46 subjects received SS treatment (SS group), 53 subjects received arthrocentesis plus HA injection (HA group). Joints with anterior disc displacement with reduction (ADDwR) and anterior disc displacement without reduction (ADDwoR) were compared separately. MRI before the beginning of the treatment and after a set of treatment were used for measurement. Disc-condyle relationship and positions of condyles and discs were determined by disc-condyle angles and X-Y coordinates.

RESULTS

The disc-condyle angles decreased significantly in the SS group (P < .0001). Whereas no significant change was found in the HA group. Substantial anteroinferior condyle movement was detected in the SS group, slight anterior movement of condyles was discovered in the HA group. Anterior shift of discs position was observed in HA group and joints with ADDwoR in the SS group.

CONCLUSIONS

SS was effective in improving the disc-condyle relationship in ADD subjects, while significant improvement of disc-condyle relationship cannot be achieved through arthrocentesis plus HA injection.

Comparison of two different therapeutic approaches for skeletal Class II patients with temporomandibular degenerative joint disease

OBJECTIVES

To compare two different therapeutic approaches for skeletal Class II patients with temporomandibular degenerative joint disease.

MATERIALS AND METHODS

A total of 47 patients were included in this study. Group anterior repositioning splint (ARS) was treated with temporomandibular joint (TMJ) disc surgery followed by an ARS and camouflage orthodontic treatment. Group stabilization splint (SS) was treated with an SS followed by orthodontic treatment combined with orthognathic surgery. Cephalometric analysis of lateral radiographs and measurements of condylar height were evaluated before and after splints.

RESULTS

In group ARS, mandibular advancement was observed after treatment in 21 of 24 patients (87.5%). The SNB angle increased by an average of 1.40 ± 1.01°. The ANB angle, overjet, Wits, and convexity decreased. Facial angle and soft tissue N Vert to pogonion increased. Vertically, MP-FH, MP-SN, y-axis, and vertical ratio decreased and ANS-Me/N-Me and S-Go/N-Me increased, suggesting a counterclockwise rotation of the mandible. In group SS, 18 of 23 patients (78.3%) showed a backward change tendency. The SNB angle reduced by 0.90 ± 0.93°. The ANB angle, overjet, Wits, convexity, and y-axis increased. The facial angle and soft tissue N Vert to soft tissue pogonion (ST N Vert to ST pogonion) decreased. Magnetic resonance imaging showed condylar height increased by 1.45 ± 3.05 mm (P = .002) in group ARS. In group SS, condylar height change was not consistent.

CONCLUSIONS

TMJ disc surgery followed by ARS promoted condylar bone remodeling and regeneration. The SNB angle increased, and the severity of skeletal Class II was improved. The SS enabled the mandible to withdraw backward and revealed a retrognathic but true mandible position.

Nonsurgical Management of Temporomandibular Joint Arthropathy

Arthropathy is a broad diagnostic term for any pathologic condition afflicting one or more joints of the body. Temporomandibular joint (TMJ) arthropathy is an umbrella term that may be applied to mechanical dysfunction or disease of one or both TMJs. This article provides evidence-based recommendations for conducting a patient evaluation, initiating a diagnostic workup, formulating an assessment, and instituting various nonsurgical modalities for the treatment of TMJ arthropathies.

Diagnosis and Treatment of Myogenous Temporomandibular Disorders: A Clinical Update

Myogenous temporomandibular disorders (M-TMDs) are the most common chronic orofacial pain, affecting the masticatory muscles and, thus, jaw movement. While a concise diagnosis is crucial to formulate a rational treatment plan, the similarities in clinical presentations that M-TMDs share with other neuromuscular disorders affecting the temporomandibular joint (TMJ) could easily confuse physicians. In addition to the basics, such as thorough history taking and meticulous clinical examinations, different imaging techniques are useful adjuncts to facilitate the diagnostic process. This review presents an overview of the current understanding on a variety of diagnostic and treatment modalities for M-TMD patients. It is essential to highlight that there is not a single treatment for all, and the benefits of multidisciplinary strategies have been noted for the effective management of myogenous TMD pain. Treatment modalities ranging from conservative to minimally invasive options are discussed in this review.

The effect of anterior repositioning splint therapy on maximum bite forces in patients with disc interference disorders

OBJECTIVE

To evaluate the effect of anterior repositioning splint (ARS) on maximum bite force (MBF) values in patients with disc interference disorders (DID).

MATERIAL AND METHODS

Twenty-two patients with disc interference disorders and 22 healthy subjects participated in to study. The Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) Axis I have been used to diagnose DID patients. All patients received ARS therapy for 6 weeks. The MBF measurement was performed with Flexi-Force piezo-resistive sensors for both healthy subjects and patients before and after ARS therapy.

RESULTS

A significant difference was recorded by the increase of the mean MBF values after the use of the ARS in the patient with disc derangements (p < .05).

CONCLUSIONS

APS therapy is efficient for eliminating pain and increasing MBF of the patients with DID. In addition, the use of FlexiForce sensors may be a practical solution to assess the bite force in the clinical setting.

The effect of functional mandibular advancement for adolescent patients with skeletal class II malocclusion on the TMJ: a systematic review and meta-analysis

OBJECTIVES

This study aimed to assess whether functional mandibular advancement (FMA) will cause temporomandibular joint disorders (TMD) or have side effects on temporomandibular joint (TMJ) in adolescent patients.

METHODS

All searched databases, including PubMed, Web of Science, EMBASE, Cochrane Central Register of Controlled Trails and Scopus were searched. Gray literature and unpublished literature was also searched. Randomized controlled trails (RCT) and non-randomized studies of the effects of interventions (NRSI) directly observe the condition of adolescent patients' TMJ after finishing treatment will be considered to include in our study. According to Cochrane Handbook, Cochrane Collaboration risk of bias tool was used to assess the quality of included RCTs, and Risk of Bias In Non-randomized Studies of Interventions (ROBINS-I) tool was used to assess the quality of included NRSIs.

RESULT

Finally 18 researches were evaluated as eligible to include in this study. 5 of the studies were RCTs, 8 were NRSIs and 5 were systematic reviews. The data of RCTs and NRSIs were statistically pooled in meta-analysis. The number of samples under investigated among primary studies was 579 individuals,there were 80 patients who developed temporomandibular symptoms during or after treatment. But all the subjective symptoms disappeared during follow-up time. The statistical outcomes proved that patients received FMA didn't show more tendency to develop temporomandibular symptoms [I2 = 27%, OR = 0.54, 95%CI (0.33,0.87), p = 0.01].

CONCLUSION

(1) TMJ symptoms may occur during the functional oral appliance wearing, but the symptoms will release or disappear after treatment or during the follow-up period. (2) Less convincing evidence indicates that slightly previous TMD and condyle-glenoid fossa relationship will be improved after treatment. (3) There is TMJ disc anterior displacement observed during treatment, but most of them will return to the normal position later. (4) Moderate evidence support that FMA will not have side effects on TMJ of adolescent patients.

RECIPROCAL CLICKING LOCATION ANALYSIS IN THE INTRAARTICULAR TEMPOROMANDIBULAR DISORDERS AFTER AXIOGRAPHY INVESTIGATION

OBJECTIVE

The aim: To investigate the peculiarities of hinge axis trajectories in patients with condyle-disc complex intraarticular Temporomandibular Disorders (TMD) and determine the average coordinates of the reciprocal clicking location by axiography.

PATIENTS AND METHODS

Materials and methods: The results of axiographic examination of 151 patients (108 females and 43 males) with TMD confirmed by MRI were analyzed. This population included 44 persons with disc displacement with reduction (DDR), 45 persons with disc displacement with reduction and intermittent locking (DDRI), 62 persons with disc displacement without reduction (DDWR). Axiographic examination was carried out using CADIAX diagnostic device. Analysis of hinge axis movements was performed and the coordinates of articular disc reduction were determined.

RESULTS

Results: The quality of hinge axis trajectories in persons with DDR, DDRI was defined mainly as average and in patients with DDWR as poor. Quantitative indicators of trajectories during protrusion-retrusion movements were not beyond the average level. The length of the mouth opening-closing trajectory in patients with DDRI and DDWR has shown a tendency to decrease. We found that on average the reciprocal closing clicking (disc reduction) occurs at a distance of 0-1.4 mm on the X-axis, 0.1-2.9 mm on the Z-axis, and 0-0.85 mm on the Y-axis.

CONCLUSION

Conclusions: The obtained wide range of reciprocal clicking location parameters indicates the priority of a personalized approach when planning preliminary treatment in order to restore the disc-condylar complex of TMJ.

An Overview of Anterior Repositioning Splint Therapy for Disc Displacement-related Temporomandibular Disorders

Anterior repositioning splint (ARS) therapy is considered one of the most effective therapies for treating disc displacement-related temporomandibular disorders (TMDs), which account for a large proportion of TMD cases. Owing to the wide application of this therapy, the exact mechanism of remission has increasingly drawn attention. Given that practitioners have different views on ARS therapy, its indications are broadened, and operating methods diverged. This review attempts to provide an overview of ARS therapy and helps practitioners establish indications and suitable operating methods. Representative views in the past 10 years were summarised, and conclusions were drawn as follows: The mechanism of ARS therapy is mainly attributed to internal derangement correction, improvement of stress distribution and recently reported joint remodeling. It has an evident effect in the short term, and the most prevalent operating methods are protruding the mandible to the edge-to-edge position and wearing the ARS for 24 hours daily for 3-6 months. However, long-term stability is not optimal, and thus indications should be selected carefully. Notably, most of the clinical studies in this field are case analyses with low-quality evidence. Well-designed RCTs are required to further validate relevant theories.

Temporomandibular disorders: improving outcomes using a multidisciplinary approach

Patients with temporomandibular disorders (TMD) can become very complex. This article aims to highlight the importance of the multimodal and multidisciplinary approach in this type of patients to improve clinical outcomes. At present we have innumerable techniques and tools to approach this type of patients from a biopsychosocial model where active and adaptive type treatments are fundamental. There are various health professions that have competence in the treatment of TMD, however, although in the most complex cases should be treated simultaneously, still too many patients receive unique treatments and only from one point of view. This review exposes the treatments available from a clinical-scientific perspective and also emphasizes the importance of working in specialized units with those professionals who have competencies on the different conditions that may occur.

Condylar repair and regeneration in adolescents/young adults with early-stage degenerative temporomandibular joint disease: A randomised controlled study

BACKGROUND

Anterior repositioning splint (ARS) can facilitate regenerative condylar remodelling.

OBJECTIVE

To determine the effect of ARS on osseous condylar changes in adolescents/young adults with early-stage degenerative joint disease (DJD).

METHODS

Sixty-nine patients with early-stage temporomandibular joint (TMJ) DJD based on the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) and cone beam computed tomography (CBCT) imaging were recruited and randomly allocated to two treatment groups: (a) conservative therapy with ARS and (b) conservative therapy without ARS. Subjects with acute TMJ closed-lock had their displaced discs physically reduced by mandibular manipulation prior to ARS therapy. Clinical and CBCT data of 59 patients (86.4% females, mean age 17.95 ± 4.53 years, 67 joints) were attained pre- and at 6 or 12 months post-treatment. Osseous changes after treatment were categorised into (a) progressed, (b) unchanged, (c) repaired (remodelled without new bone formation) and (d) regenerated (remodelled with new bone formation). Statistical analysis including chi-square test, independent samples t test or Mann-Whitney U test was conducted.

RESULTS

About 85.5% of patients (59/69) completed the study, with 28 subjects (32 joints) in the splint group and 31 (35 joints) in the control group. The occurrence of condylar repair and regeneration was significantly higher with ARS (78.1%/[25/32] of joints) when compared to control group (48.6%/[17/35]) (P < 0.05). Moreover, condylar regeneration was exclusively observed in 50%/(16/32) of joints with ARS. For the 14 joints in splint group that received physical TMJ closed-lock reduction, 85.7%/(12/14) exhibited condylar regeneration. The splint group (3.1%/[1/32]) also had significantly lower incidence of progressive TMJ degeneration than the control (37.1%/[13/35]) (P < 0.001).

CONCLUSION

Condylar repair and regeneration in early-stage TMJ DJD are possible, and ideal spatial disc-condyle relationship appears important. The possibility of restoring TMJ form/structure by ARS therapy presents an attractive area of new basic science and clinical research (Bone defect repair in early osteoarthrosis of temporomandibular joint by joint distraction therapy: A randomized controlled trial/ChiCTR-TRC-14005172).

Can anterior repositioning splint effectively treat temporomandibular joint disc displacement?

The aim of this study was to determine whether anterior repositioning splint (ARS) can effectively treat temporomandibular joint (TMJ) anterior disc displacement with reduction (DDwR) in juvenile Class II patients. This study investigated disc repositioning clinically and through use of MRI with 12-month follow up. Patients with skeletal Class II malocclusions and DDwR diagnosed by magnetic resonance imaging (MRI) were treated with ARS. The efficacy of ARS was assessed clinically and by means of MRI before treatment (T0), immediately after bite registration (T1), at the end of treatment (T2), and at 12 months after functional appliance treatment (T3). Improvement in TMJ pain, TMJ noises, and range of mandibular movement were assessed. MRI evaluation was based on disc-condylar relationship in parasagittal images. Seventy-two juvenile patients with 91 joints were included in this study. The average age was 15.7 years old (range, 10–20 years) at first visit. There were statistically significant reductions in TMJ pain, disability in daily life and TMJ clicking (P < 0.01). MRI at T2 indicated that the success rate was 92.31% (84/91), but decreased to 72.53% (66/91) at T3. The unsuccessful splint disc capture was mainly observed in late adolescence, especially over 18 years old. Using MRI results as the gold standard, we found that clinical assessment had an accuracy rate of 75.82% at 12-month follow-up. In conclusion, although success rate for ARS treatment decreased over time, both clinical findings and MRI examination indicate that the ARS is relatively effective in repositioning the DDwR, especially for patients in early puberty. However, further and larger studies are needed to evaluate the outcome with ARS.