Mouth opening, jaw disability, neck disability, pressure pain thresholds, and myofascial trigger points in patients with disc displacement with reduction: A descriptive and comparative study

OBJECTIVE

To assess jaw and neck function, pressure pain threshold (PPT), and the presence of trigger points (TrPs) in disc displacement with reduction (DDWR) subjects compared to healthy subjects.

METHODS

One hundred DDWR subjects and 100 matched controls were studied. Clinical evaluations included demographic data, range of motion, jaw and neck disability, PPT, and muscle TrPs.

RESULTS

DDWR subjects have limited pain-free opening limitation (p < 0.001), jaw and neck disability limitation (p < 0.001), and higher presence of active and latent TrPs limitation (p < 0.001) compared to healthy subjects.

CONCLUSION

DDWR subjects present a limited pain-free mouth opening, higher jaw and neck disability, lower PPT, and major presence of active and latent TrPs compared to healthy subjects. Cervical spine and TMJ evaluation and treatment should be considered in DDWR patients.

Exploring the effect of disc displacement on the risk and severity of condylar erosion in adult temporomandibular disorder patients: A CBCT and MRI study

OBJECTIVE

The objective of the study was to investigate the relationship between types of disc displacement (DD) diagnosed by magnetic resonance imaging (MRI), and the risk (presence or absence) and severity of condylar erosion (CE) graded using cone-beam computed tomography (CBCT) in adult Temporomandibular disorders (TMD) patients.

METHODS

A total of 353 TMD patients (283 females, 70 males) underwent MRI scans to categorise DD as normal (NA), anterior displacement with reduction (ADDR), or anterior displacement without reduction (ADDNR). CE severity was graded on a scale of 0-3 (absence, mild, moderate or severe) using CBCT. To establish the plausibility and cut-off points for CE diagnosis, the severity of CE was then further divided into three classifications: Grade 0 versus 1 + 2 + 3; Grades 0 + 1 versus 2 + 3; Grades 0 + 1 + 2 versus 3. Logistic regression analysis was performed, adjusting for age, gender and joint correlation.

RESULTS

ADDNR significantly increased the risk of CE compared with NA (OR = 10.04, 95% CI: [6.41, 15.73]) and showed a significant increase in CE severity across all classifications (ORs = 10.04-18.95). The effects of ADDNR were significant in both genders (p < .001) and had a greater impact in females. ADDR was predominantly associated with mild CE.

CONCLUSIONS

ADDNR significantly increased the risk and severity of CE independent of gender when compared to NA, whereas ADDR was mainly associated with mild CE. Slight cortical discontinuity may represent a subclinical diagnosis requiring further investigation.

Correlation between TMJ Space Alteration and Disc Displacement: A Retrospective CBCT and MRI Study

This study aims to determine if a large anterior and reduced posterior/superior joint space is highly predictable for disc displacement. From patients with temporomandibular disorders symptoms, fifty-two experimental joints and fourteen control joints were included. The cone beam computed tomography (CBCT) images were used to calculate posterior-to-anterior (P-A) and superior-to-anterior (S-A) joint space ratios, while disc position was determined using magnetic resonance imaging (MRI). One-way analysis of covariance test and receiver operating characteristics analysis were carried out. The results showed that among the 52 experimental joints, 45 were diagnosed as disc displacement and 7 as normal disc positions (N). All 14 control joints showed normal disc positions. The P-A ratio was 1.46 ± 0.21, 0.99 ± 0.23, and 0.86 ± 0.30 in the control, N, and DD groups, respectively (p < 0.001). The S-A ratio was 1.80 ± 0.27, 1.44 ± 0.33, and 1.08 ± 0.35 in the control, N, and DD groups, respectively (p < 0.001). When an altered P-A ratio and/or S-A ratio are observed on the CBCT, the diagnosis of disc displacement is quite predictable with high sensitivity and specificity.

Platelet-rich plasma injections for the treatment of temporomandibular joint disorders: A systematic review

OBJECTIVE

This systematic review aimed to investigate and examine whether intra-articular injections of platelet-rich plasma (PRP) after arthrocentesis are beneficial for the treatment of temporomandibular disorders, when compared to other treatments, such as injections of hyaluronic acid (HA) or saline after arthrocentesis.

METHODS

An electronic search on PubMed was performed using combinations of the terms 'temporomandibular' and 'platelet rich plasma', to identify studies reported in English and published up until 2017. The initial screening identified 222 records, of which only seven fulfilled the inclusion criteria and were included in this review. Of these studies, three compared injection of PRP after arthrocentesis with the injection of HA after arthrocentesis, while two compared injection of PRP after arthrocentesis with Ringer's lactate after arthrocentesis and one compared injection of PRP after arthrocentesis to sodium chloride.

RESULTS

Five of the studies found that PRP injections have led to significant improvements in mandibular range of motion and pain intensity up to 12 months after treatment, while the remaining two studies found similar results for the different treatments.

CONCLUSION

However, a standardized protocol for PRP preparation and application needs to be established.

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.

Craniofacial Morphology of Temporomandibular Disorder Patients with Different Disc Positions: Stratifying Features Based on Sex and Sagittal Skeletal Pattern

Disc displacement (DD) appears in the majority of temporomandibular disorder (TMD) patients. The correlation between craniofacial morphology and different disc positions has been underlined, while the craniofacial morphological differences based on sex and sagittal skeletal pattern stratification have been insufficiently studied. In this study, 304 patients with TMD complaints were included and classified into normal position, disc displacement with reduction (DDwR) and disc displacement without reduction (DDwoR) groups according to magnetic resonance imaging. A total of 24 cephalometric measurements, covering the cranial base, vertical relationship, sagittal relationship, mandible position and morphology, and dental relationship, were assessed using lateral cephalograms. A stratified analysis was performed based on the sex and sagittal skeletal pattern. Overall, DD patients had distinctive craniofacial morphological features. The posterior cranial base length and mandibular arc angle were statistically different only in females, while the Y-axis angle, occlusal plane angle and sella nasion point A angle (SNA) might be unique features in males. Skeletal class II had the most statistically different measurements compared to the others. Differences in the Frankfort mandibular incisor angle (FMIA) and saddle angle were especially displayed in skeletal class III patients. The sex and skeletal sagittal pattern could affect the morphological differences in TMD patients with different disc positions.

A clinical study on the incidence of internal derangement of the temporomandibular joint following harvesting of temporalis fascia

OBJECTIVE

The aim of the current clinical study was to reveal whether harvesting of a temporalis fascia graft would be associated with a higher incidence of temporomandibular joint (TMJ) internal derangement.

METHODS

The study group involved 104 patients who had middle-ear operations, 67 of which involved harvesting of temporalis fascia and 37 that did not. The TMJs were clinically examined in each group.

RESULTS

The total incidence of internal derangement of the TMJ was significantly higher in the group that had temporalis fascia harvesting (79.1%), compared to the group that did not have temporalis fascia harvesting (29.7%), (p= 0.001).

CONCLUSION

Harvesting of temporalis fascia probably alters mandibular kinematics and predisposes to internal derangement of the TMJs.

Diagnostic use of computerized axiography in TMJ disc displacements

Application of paraclinical methods for investigating the temporomandibular joint (TMJ) has been a subject of constant controversy due to the absence of universally-accepted criteria and lack of consensus regarding their usage. Compared with medical imaging, which provides a structural analysis of the TMJ, axiography involves the functional recording of condylar movements. The aim of the present study was to explore the diagnostic value of computerized axiography for TMJ disc displacements using MRI as the reference standard. The present study included 33 (66 TMJs) patients clinically diagnosed with TMJ disc displacements. On the same day, all patients underwent clinical examination and computerized axiography measurements using Cadiax Compact^® II before undergoing MRI (1.5 T) 1-7 days later. The characteristics of the diagnostic parameters, namely sensitivity, specificity, positive and negative predictive values, accuracy, Youden index and the 95% confidence intervals (CI), were all computed. Compared with MRI, computerized axiography yielded a sensitivity of 85.11%, specificity of 94.74%, positive predictive value of 97.56%, negative predictive value of 72% and a diagnostic accuracy of 87.88% for any disc displacements. This suggests that computerized axiography can confer high sensitivity, specificity and accuracy for the diagnosis of TMJ disc displacements. However, axiographic analysis has no diagnostic significance in TMJ function if not associated with clinical examination.

Positional and dimensional TMJ characteristics in different temporomandibular disorders: A cross-sectional comparative study

OBJECTIVE

To investigate the morphological and positional temporomandibular joint (TMJ) characteristics of different temporomandibular disorders (TMDs).

METHODS

One hundred forty-three TMD patients were divided into three groups: Group 1: Myalgia (M), Group 2: Disc displacement with reduction (DDWR), and Group 3: Disc displacement without reduction (DDWOR). Three-dimensional positional and dimensional parameters of the TMJ, including mandibular fossa, condyle, and TMJ spaces were evaluated using cone beam computed tomography (CBCT). The significance level was p < 0.05.

RESULTS

Mandibular condyles were significantly positioned in more vertical, posterior, and medial directions, with the reduced condylar width in the DD groups (p < 0.001). Anterior joint space was significantly higher in the DDWR group than the myalgia group; the superior joint spaces were more reduced in DD groups than the myalgia group.

CONCLUSION

Patients diagnosed with disc displacement showed significantly different condylar positions and joint spaces compared to the myalgia group in a skeletally comparable sample.

Inter-examiner reliability of the Chinese version of Axis I diagnoses of the diagnostic criteria for temporomandibular disorders

OBJECTIVE

To evaluate the inter-examiner reliability of the Chinese version of the Axis I diagnoses of the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) and to compare the consistency between clinical diagnoses and magnetic resonance imaging (MRI).

METHODS

Sixty-seven individuals were evaluated by three TMD specialists, and 49 underwent MRI examination. Cohen's Kappa coefficient (κ) was used to evaluate the inter-examiner reliability and the consistency between clinical diagnoses and MRI manifestations.

RESULTS

Diagnostic agreement was good to excellent for pain and disc displacement with or without reduction (κ = 0.659-1.000). Agreement between clinical diagnoses and MRI findings was fair to good (κ = 0.400).

CONCLUSION

Inter-examiner diagnostic reliability using the Chinese version of the DC/TMD Axis I instruments was excellent, especially for arthrogenic TMDs.

Modic changes and its association with other MRI phenotypes in east Anatolian low back pain patients

OBJECTIVE

Modic changes (MCs) are known to be associated with low back pain (LBP). Literature contains conflicting reports about the prevalence of MCs and other spinal phenotypes among different populations with LBP patients. We aimed to evaluate the prevalence of MCs in the lumbar spine and associated features in Eastern Anatolian chronic LBP patients.

METHODS

The study sample comprised of 786 consecutive patients [(490 female, 296 male), (mean age 39.7; range 20-78)] with a history of low back pain for at least 3 months. Data about MCs involvement, Schmorl's nodes (SN), disc degeneration (DD), disc displacement, disc height and osteophytes were obtained via MRI. Patients' demographic characteristics, Oswestry disability index (ODI) and visual analog scale (VAS) scores were assessed using a questionnaire.

RESULTS

MCs were present in 67.2% (528/786) of the patients. Of all evaluated lumbar-level changes, 86 (6.2%) were Type I, 991 (76.8%) were Type II, 11 (0.8%) were Type III, 47 (6.5%) were Type II/III, 89 (8.5%) were Type I/II, and 29 (1.2%) were Type I/II/III MCs. MCs were significantly associated with severe DD (p < 0.001), disc displacement (p < 0.001), SN (p < 0.001), and osteophytes (p < 0.001). In the multivariate regression analysis, BMI (for both ODI and VAS) and age (only for ODI) were the only independent predictors of clinical severity.

CONCLUSIONS

The present study is the largest cross-sectional study of adult members of the Eastern Anatolian population with chronic LBP. Modic changes were detected in 67.2% of patients with chronic LBP and the prevalence of other phenotypic features differed significantly between MCs and non-MCs disc levels. Nevertheless, the results of the current study do not support a causal relationship of MCs or any MRI changes with clinical symptom severity.

Comparing anxiety levels and patient comfort during single- and double-puncture arthrocentesis

OBJECTIVE

To compare the comfort and anxiety levels of patients undergoing two different temporomandibular joint (TMJ) arthrocentesis techniques.

METHODS

Fifty female patients were randomly assigned into two groups of 25 based on the treatment modality: Group 1, single-puncture Type-1 arthrocentesis (SPA); Group 2, conventional double-puncture arthrocentesis (DPA). Preoperative and postoperative anxiety was scored with the State-Trait Anxiety Inventory-S (STAI-S) questionnaire. Blood pressure and heart rate were assessed preoperatively during the application of local anesthesia and at needle insertion into the joint cavity, the 5th and 10th minute of the procedure, and end of the procedure.

RESULTS

STAI-S scores were lower postoperative than preoperative in both groups. Heart rate and mean arterial pressure were highest during anesthesia and needle insertion (p < 0.005). Changes in heart rate, mean arterial pressure, and STAI-S scores were statistically similar between the groups.

CONCLUSION

DPA and SPA were tolerated similarly by the patients.

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.

COL12A1 Single Nucleotide Polymorphisms rs240736 and rs970547 Are Not Associated with Temporomandibular Joint Disc Displacement without Reduction

Temporomandibular disorders (TMDs) may affect up to 25% of the population, with almost 70% of these TMD cases developing malpositioning of the disc over time in what is known as internal derangement (ID). Despite significant efforts, the molecular mechanism underlying disease progression is not yet very well known. In this study, the role of COL12A1 rs970547 and rs240736 polymorphisms as potential genetic factors regulating ID was investigated. The study included 124 Caucasian patients of both sexes after disc displacement without reduction (DDwoR) in either one or two temporomandibular joints (TMJs), either of which meet the criteria for this condition. All patients underwent clinical examination and 3D digital imaging. The COL12A1 rs970547 and rs240736 polymorphisms were evaluated. There were no statistically significant differences in the chi-square test between the study group and healthy controls. The examined COL12A1 rs240736 and rs970547 polymorphisms do not contribute to DDwoR in Polish Caucasians.

Low skeletal bone mineral density as a potential aetiological factor towards idiopathic condylar resorption

The aim of this study was to investigate the contributing factor of impaired skeletal quality in the pathogenesis of idiopathic condylar resorption (ICR). One hundred and twenty-six patients with MRI-confirmed ICR and 596 patients with disc displacement (DD) without a diminished condyle, of both sexes, were included. Dental examinations and retrospective surveys regarding temporomandibular joint symptoms and progression of maxillofacial deformities were conducted. Skeletal bone mineral density (BMD) was measured by dual energy X-ray absorptiometry (DXA) and converted to T-scores and Z-scores. Results showed that ICR patients had a smaller overbite (1.56±3.3 vs 3.05±2.0mm), larger overjet (4.9±2.4 vs 3.5±1.9mm), larger range of mouth opening (36.5±6.7 vs 33.6±7.1mm), and higher rates of anterior open bite and mandibular retrusion compared to DD patients (all P<0.001). ICR was associated with an increased probability of low skeletal BMD at chronological age in females (P=0.020) but not in males (P=0.095). This study indicates that reduced BMD may predispose females to an exacerbated condylar resorption process in addition to increased joint loading initiated from DD.

Interexaminer reliability of the German version of the DC/TMD

AIM

Verification of the interrater reliability of axis I diagnoses of the German version of the DC/TMD. The hypothesis was that the DC/TMD protocol yields comparable results, if examiner instructions are closely followed.

MATERIAL AND METHODS

A culturally equivalent German translation of the DC/TMD was developed. During a 1-day calibration workshop at the University of Heidelberg, three examiners were trained by the DC/TMD Training and Calibration Center. According to the calibration guidelines, 16 models (11 cases, five non-cases) were examined by four experienced TMD specialists. Reliability was calculated with reference to the reference standard examiner as percentage agreement and kappa coefficients for DC/TMD diagnoses and intraclass correlation coefficients (ICCs) for findings.

RESULTS

Excellent reliability was achieved for the diagnoses myalgia, myofascial pain with referral, arthralgia, headache attributed to TMD, disc displacement (DD) with reduction, DD without reduction without limited opening (κ = 0.85…1.00). Degenerative joint disease was diagnosed with substantial agreement (κ = 0.64), DD with reduction with intermittent locking and DD without reduction with limited opening were not present in our sample. Overall percentage agreement was 94%-100% for all diagnoses.

CONCLUSION

The German version of the DC/TMD shows very good reliability and can be recommended for the use in clinical and research settings.

Magnetic resonance imaging-guided disc-condyle relationship adjustment via articulation: a technical note and case series

A normal disc-condyle relationship is crucial to the health and function of the temporomandibular joint. We herein introduce a novel technique that can precisely and rapidly restore the disc-condyle relationship. An initial bite rim was made, and the patient was instructed to wear this bite rim during magnetic resonance imaging (MRI) scanning. A quick MRI scan was performed, and the disc-condyle relationship and direction and vector of the displacement was measured. Adjustments to the mandible position were made on an articulator based on the measurements, after which a second bite rim was made. A second quick preview MRI scan was immediately performed, and the images were evaluated and measured again. Additional adjustments were made as needed, and the preview scan was repeated until an ideal disc-condyle relationship was achieved. Once a good disc-condyle relationship was acquired, the mandible position was recorded as the treatment mandible position, and a splint was fabricated. MRI visualization enabled precise and very fine adjustment of the disc-condyle relationship by articulating. This technique might help to simplify the clinical process and improve treatment effectiveness.

Characteristics of patients with temporomandibular joint osteoarthrosis on magnetic resonance imaging

INTRODUCTION

Temporomandibular joint (TMJ) dysfunction is a common condition that is best evaluated with magnetic resonance (MR) imaging. The aim of this study was to investigate the characteristics of the patients with TMJ osteoarthrosis on MR imaging.

METHODS

The MR images of 206 TMJs of 103 patients with temporomandibular disorders (TMD) were evaluated retrospectively in this study. The relationship between osteoarthrosis and age, gender, TMJ pain and MR imaging findings, such as disc displacement with or without reduction and TMJ effusion, was analysed.

RESULTS

The patients with TMJ osteoarthrosis (mean: 51.6 years) were significantly older than those without osteoarthrosis (mean: 44.8 years, P = 0.027). The incidence of the patients with TMJ osteoarthrosis was significantly different between with (10.0 %) and without reduction (57.0 %, P < 0.001). Logistic multivariate regression analysis demonstrated that disc displacement without reduction was significant in patients with TMJ osteoarthrosis (odds ratio = 12.285, P < 0.001).

CONCLUSIONS

This study suggests that characteristics of the patients with TMJ osteoarthrosis on MR imaging include older and disc displacement without reduction.

Comparison of two needles arthrocentesis versus double needle cannula arthrocentesis in the treatment of temporomandibular disc displacement

OBJECTIVE

To compare clinical and imaging results of two needles arthrocentesis (TNA) versus double-needle cannula arthrocentesis (DNCA) in the treatment of temporomandibular joint disc displacement (DD).

METHODS

Twenty patients with DD were randomly divided into two groups: TNA and DNCA. Clinical data (pain scores; maximal interincisal distance [MID], and protrusion and laterality movements) were evaluated before and 24 months after the arthrocentesis. Disc and condyle position and joint effusion (JE) were evaluated by magnetic resonance exams.

RESULTS

Both groups presented improvement in the MID, including pain reduction, modifications in disc and condyle positions, and reduction of the presence of JE, without difference between groups (p > 0.05). The DNCA was performed significantly faster (p = 0.0001).

CONCLUSION

Both TNA and DNCA are efficient in promoting improvement in the MID: reduction in pain, modifications in disc and condyle positions, and, in part, may account for less JE, without difference between techniques.

Painful clicking jaw: a pictorial review of internal derangement of the temporomandibular joint

Temporomandibular joint disorders are a common cause of chronic musculoskeletal pain worldwide. Among these, internal disc derangement is the most frequent type of disorder. Internal derangement is defined as an abnormal positional and functional relationship between the disc and articulating surfaces. Common clinical symptoms include pain and clicking.

Imaging plays a key role in diagnosing temporomandibular joint disorders. It is important for the radiologist to detect early imaging signs of internal derangement, thereby avoiding the evolution of this condition to degenerative joint disease. The aim of this article is to familiarise the reader with the spectrum of imaging findings that are encountered at different stages of the disease.

Dopamine receptor D2 and ankyrin repeat domain containing one in temporomandibular disorder of adolescents

BACKGROUND

Temporomandibular disorder (TMD) is a multifactorial condition that combines environmental and genetic factors and its prevalence increases during adolescence.

AIM

To investigate the association between TMD and genetic polymorphisms in the DRD2 and ANKK1 in a population of Brazilian adolescents.

DESIGN

The TMD group included adolescents diagnosed with any of the following TMD subgroups according to the RDC/TMD criteria: myofascial pain, arthralgia and disc displacement and painful TMD. Genomic DNA for molecular analysis was extracted from buccal cells, and genetic polymorphism rs6275 in DRD2 and rs1800497 in ANKK1 were genotyped by real-time polymerase chain reactions using the TaqMan assay. Data were analysed using the Epi Info 3.5.7 and Stata software, with significance level of 0.05.

RESULTS

Two hundred fifty-one individuals were included in this study, 148 subjects presented TMD. For disc displacement, the genetic polymorphisms rs6275 was associated in a recessive model (P = 0.04), whereas the rs6276 and rs1800497 presented only a borderline association in a recessive and dominant models, respectively (P = 0.07 and P = 0.06).

CONCLUSION

The genetic polymorphism rs6275 in DRD2 was associated with disc displacement in Brazilian adolescents.

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).

Articular soft tissue injuries associated with mandibular condyle fractures and the effects on oral function

The majority of studies debating the optimization of treatment for condylar mandibular fractures focus on the bony aspect first. However, fractures of the mandibular condyle may go together with soft tissue injury of the temporomandibular joint. An electronic literature search for this topic was undertaken. Assessment of quality was carried out using the Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. Sixteen articles were included in this review. The reviewed literature showed that intracapsular fractures and dislocated condylar fractures result in more severe injuries. Serious injury to the disc and capsule of the temporomandibular joint is a contributing factor towards development of complications after closed treatment. The results of this review give an overview of the published studies focusing on articular soft tissue injuries caused by condylar mandibular fractures. Additionally, an overview of the magnetic resonance imaging (MRI) settings used to detect these injuries is provided. Until now, the relation between soft tissue injuries and type of condylar trauma and their influence on clinical outcome has been insufficiently investigated. Before considering reduction of soft tissues next to reduction of the fracture, more research is needed into the impact of soft tissue injuries on oral functioning, in which a uniform classification is used.

Temporomandibular joint anterior disc displacement with reduction in a young population: Prevalence and risk indicators

BACKGROUND

Temporomandibular joint (TMJ) anterior disc displacements with reduction (ADDR) are commonly found in the young population and often found to be associated with biomechanical and anatomical factors. Until now, most knowledge on ADDR among children and adolescents comes from studies performed on Caucasian subjects.

AIMS

To assess the clinically determined prevalence rates of ADDR among the young Indonesian population and to evaluate its risk indicators.

DESIGN

In this cross-sectional study, 1562 pupils and students of 7-21 years old completed a questionnaire and underwent a clinical examination.

RESULTS

The prevalence rates of ADDR were 7.0% among children (7-12 years), 14.4% among adolescents (13-18 years), and 12.3% among young adults (19-21 years). Logistic regression analyses revealed that increasing age and lip biting were associated with ADDR in children, whereas pen biting was associated with ADDR in the adolescent population. None of the included factors were found to be associated with ADDR in the young adult population.

CONCLUSIONS

The present findings indicate that prevalence of ADDR increases with age, with a peak during the years of adolescence. Biomechanical factors seem to play a significant role in ADDR development.

Biochemical changes associated with temporomandibular disorders

OBJECTIVE

To assess vitamin D, parathyroid hormone, calcitonin, calcium, phosphorus and magnesium levels in patients with versus without temporomandibular disorders (TMDs).

METHODS

This prospective observational study included patients with TMDs and age-matched healthy controls. TMDs were diagnosed via physical and radiologic examination, and serum levels of 25 (OH) vitamin D, parathyroid hormone, calcitonin, calcium, magnesium, and phosphorus were determined. The impact of age, sex and seasonal variations in serum 25 (OH) vitamin D levels was controlled by the inclusion of age, sex and date-matched control patients.

RESULTS

The study included 100 patients, comprising 50 patients with TMDs and 50 control patients. No statistically significant between-group differences were found regarding age or sex. No statistically significant between-group differences were found in terms of serum 25 (OH) vitamin D, calcitonin, calcium, magnesium or phosphorus levels. Parathyroid hormone levels were statistically significantly higher in patients with TMDs versus healthy control patients.

CONCLUSION

In patients with temporomandibular disorders, increased parathyroid hormone levels in response to vitamin D deficiency was significantly more prominent. These data suggest that, in patients with temporomandibular disorders, vitamin D deficiency should be assessed and corrected.

Study of stress-induced temporomandibular disorders among dental students: An institutional study

Aim and Objectives:

The aim and objectives of this study are to investigate the various types of stress-inducing factors, most prevalent etiological factor and to determine the correlation between stress and temporomandibular disorders (TMDs) in Dental students in Modinagar, Ghaziabad, Uttar Pradesh.

Materials and Methods:

A sample of 450 students were selected for the study divided into two groups of undergraduate (UG) and postgraduate (PG) students further subdivided into UG (1^st, 2^nd, 3^rd, and 4^th, interns) and PG (1^st, 2^nd, 3^rd year). Study includes clinical evaluation of temporomandibular joint (TMJ) system (TMJ sounds, muscles of mastications, mouth opening, and range of mandibular motion) and questionnaire which covers demographic data (i.e., age, sex, and academic year), TMD symptoms and TMD signs along with standardized scales related to stress dental environmental stress scale and perceived stress scale (PSS).

Results:

Most of the students included into study are mostly of 21–25 years of age (64.3%), males (52.7%), females 47.3% with more number of UGs (91.4%) predominantly 1^st year students (23.9%). Headache was found to be the most prevalent TMD symptom (26.2%) followed by clicking (24.9%), pain on clicking (5.5%), jaw lock (3.4), and difficulty in mouth opening (0.9%). Clicking was found to be the most prevalent TMD sign (24.9%) among dental students followed by deviation (16.3%), muscle tenderness (14.3%), and TMJ pain (5.7%). The most prevalent TMD was disc displacement 22.6% followed by myofascial pain dysfunction syndrome (MPDS) with disc displacement (13.5%) and MPDS (3.8%). TMD was higher in UG females students of 21–-25 years of age group, dental environment stress scale score and PSS score shows statistically significant results.

Conclusion:

Stress is a significant etiologic factor involved in initiation and maintenance of TMDs in Dental students.

Outcomes and patient satisfaction following individualized physical therapy treatment for patients diagnosed with temporomandibular disc displacement without reduction with limited opening: A cross-sectional study

OBJECTIVE

To investigate physical therapy treatment outcomes and patient satisfaction in patients with a diagnosis of disc displacement without reduction with limited opening (DDWoR wLO).

METHODS

Records of 97 patients with DDWoR wLO who received physical therapy in one outpatient clinic were used in this cross-sectional study. Outcomes included number of visits, maximum active interincisal opening, self-reported pain, and patient satisfaction.

RESULTS

The average number of physical therapy visits per patient was 5.5, and there were significant improvements in pain rating and interincisal opening following physical therapy. Effect sizes for these comparisons were large (>1.0). Mean patient satisfaction responses across all symptom areas was consistent with patients being more than less satisfied following treatment.

DISCUSSION

Individualized physical therapy treatment is an effective conservative intervention to improve mouth opening, reduce pain, and provide patient satisfaction in patients with one specific sub-type of temporomandibular disorder (TMD), DDWoR wLO.

Three-dimensional analysis of jaw kinematic alterations in patients with chronic TMD - disc displacement with reduction

The study investigated whether chronic TMD patients with disc displacement with reduction (DDR), performing non-assisted maximum jaw movements, presented any changes in their mandibular kinematics with respect to an age-matched control group. Moreover, it was examined whether jaw kinematics and a valid clinic measure of oro-facial functional status have significant associations. Maximum mouth opening, mandible protrusion and bilateral laterotrusions were performed by 20 patients (18 women, 2 men; age, 18-34 years) and 20 healthy controls (17 women, 3 men; age, 20-31 years). The three-dimensional coordinates of their mandibular interincisor and condylar reference points were recorded by means of an optoelectronic motion analyser and were used to quantitatively assess their range of motion, velocity, symmetry and synchrony. Three functional indices (opening-closing, mandibular rototranslation, laterotrusion - right and left - and protrusion) were devised to summarise subject's overall performance, and their correlation with the outcome of a clinical protocol, the oro-facial myofunctional evaluation with scores (OMES), was investigated. TMD patients were able to reach maximum excursions of jaw movements comparable to healthy subjects' performances. However, their opening and closing mandibular movements were characterised by remarkable asynchrony of condylar translation. They had also reduced jaw closing velocity and asymmetric laterotrusions. The functional indices proved to well summarise the global condition of jaw kinematics, highlighting the presence of alterations in TMD-DDR patients, and were linearly correlated with the oro-facial functional status. The jaw kinematic alterations seem to reflect both oro-facial motor behaviour adaptation and a DDR-related articular impairment.

Assessment of magnetic resonance images of displacement of the disc of the temporomandibular joint in different types of condylar fracture

To evaluate the displacement of the disc of the temporomandibular joint (TMJ) in different types of condylar fracture we studied 160 patients (222 joints) from May 2009-June 2014. All patients had computed tomographic scans (CT) and magnetic resonance images (MRI) taken preoperatively, and 24 patients (32 joints) had MRI postoperatively. CT scans were reviewed to categorise the types of condylar fracture (intracapsular, condylar neck, and subcondylar), and intracapsular condylar fractures were further classified into subtypes A, B, C, and M. MRI were then reviewed to record the position of the disc in each type of condylar fracture. The results were compared using the chi square test. There were 160 intracapsular condylar fractures, 40 fractures of the condylar neck, and 22 subcondylar fractures. Of the intracapsular condylar fractures, 75 were type A, 49 type B, 11 type C, and 25 type M. Discs were displaced in 153 intracapsular condylar fractures, 17 fractures of the condylar neck, and eight subcondylar fractures. Among the type A intracapsular condylar fractures, discs were displaced in 71/75, type B in 47/49, type C in 10/11, and in all 25 type M. The incidence of displaced discs between intracapsular condylar fractures on the one hand, and those of the condylar neck or subcondylar region on the other, was significant (p<0.001), but there were no differences among the various subtypes of intracapsular condylar fractures. Postoperative MRI showed successful results in 28/32 joints. Intracapsular condylar fractures were more likely to have displaced discs than the other types. But there were no differences among different subtypes of intracapsular condylar fractures.

Jaw disorders in the pediatric population

PURPOSE

This article will review the etiology, risk factors, history, and physical assessment of temporomandibular joint disorders (TMDs). In particular, this article discusses the role of the pediatric provider in diagnosing and beginning the initial treatment of TMDs, as well as the appropriate treatment plans. It also reveals some of the controversies regarding etiology and treatment of TMDs, as well as the paucity of research specific to TMDs in pediatrics.

DATA SOURCES

A computerized search in PubMed and Ovid Medline, from 2006 to 2012, was conducted. A few seminal articles were included that were published before 2006. Hand searching was also performed, which included a few articles between 2012 and 2015.

CONCLUSIONS

Although TMDs are mostly found in adults, it is also a finding in pediatrics, which increases in prevalence during adolescence. More research specific to pediatric patients with TMDs needs to be conducted so that pediatric-specific care can be provided.

IMPLICATIONS FOR PRACTICE

TMD is a condition found in the pediatric population, and it is important for providers to take an adequate history and physical examination that incorporates the temporomandibular joint (TMJ) and muscles of mastication. It is also critical that providers begin initial education and management, followed by appropriate referrals.

Tumor necrosis factor mediates temporomandibular joint bone tissue resorption in rheumatoid arthritis

OBJECTIVE

To investigate if TNF, IL-1 or their endogenous controls, in relation to ACPA, are associated with radiological signs of ongoing temporomandibular joint (TMJ) bone tissue resorption and disc displacement in RA patients.

METHODS

Twenty-two consecutive outpatients with TMJ of RA were included. Systemic inflammatory activity was assessed by DAS28. The number of painful regions in the body and ESR, CRP, RF and ACPA were analyzed. TMJ synovial fluid and blood samples were obtained and analyzed for TNF, TNFsRII, IL-1ra, IL-1sRII and ACPA. The ratios between the mediators and their endogenous control receptors were used in the statistical analysis. Magnetic resonance imaging was performed in closed- and open-mouth positions and evaluated regarding disc position and presence of condylar and temporal erosions of the TMJ.

RESULTS

A high TNF level in relation to TNFsRII in TMJ synovial fluid correlated to the degree of TMJ condylar erosion. A high IL-1ra level in relation to TNF in TMJ synovial fluid was also correlated to the degree of TMJ condylar erosion. The total degree of TMJ condylar erosion was correlated with the number of painful regions.

CONCLUSION

This study indicates that TNF in TMJ synovial fluid mediates TMJ cartilage and bone tissue resorption in RA. The study also suggests that the degree of endogenous cytokine control is of importance for development of bone tissue destruction.

The effects of TMJ symptoms on skeletal morphology in orthodontic patients with TMJ disc displacement

OBJECTIVE

The aim of this study was to investigate the effects of temporomandibular joint (TMJ) symptoms on skeletal morphologies of orthodontic patients with TMJ disc displacement (DD).

MATERIALS AND METHODS

The sample consisted of 197 women seeking orthodontic treatment. The subjects were divided into two groups according to the presence of TMJ symptoms: the presence and absence of TMJ symptoms. Each group was sub-divided into three groups based on magnetic resonance images of bilateral TMJs: bilateral normal disc position (BN), bilateral disc displacement with reduction (DDR) and bilateral disc displacement without reduction (DDNR). Seventeen variables from lateral cephalograms were analyzed by two-way analysis of variance to identify differences in skeletal morphologies with respect to TMJ symptoms and TMJ DD status.

RESULTS

Patients with TMJ DD were more likely to have short ramus height, short mandibular body length and backward positioning of the ramus and mandible. These skeletal morphologies became more severe as TMJ DD progressed to DDNR. However, the skeletal morphologies associated with TMJ DD were not significantly different between symptomatic and asymptomatic patients. As a result, patients with TMJ DD had backward positioning and clockwise rotation compared to those with bilateral normal TMJs, irrespective of the presence of TMJ symptom.

CONCLUSIONS

This study suggests that TMJ DD is associated with altered skeletal morphology, but TMJ symptoms do not significantly influence the relationships between TMJ DD and skeletal morphology.

Deterioration of mechanical properties of discs in chronically inflamed TMJ

Temporomandibular joint (TMJ) discs frequently undergo degenerative changes in arthritis. However, the biomechanical properties of pathogenic discs remain to be explored. In this study, we evaluated the effects of chronic inflammation on the biomechanical properties of TMJ discs in rats. Chronic inflammation of TMJs was induced by double intra-articular injections of complete Freund's adjuvant for 5 weeks, and biomechanical properties and ultrastructure of the discs were examined by mechanical testing, scanning electron microscopy, and transmission electron microscopy. The instantaneous compressive moduli of the anterior and posterior bands of discs in inflamed TMJs were decreased significantly compared with those in the control group. The instantaneous tensile moduli of the discs of inflamed TMJs also showed significant decreases in both the anterior-posterior and mesial-lateral directions. The relaxation moduli of the discs of inflamed TMJs showed nearly the same tendency as the instantaneous moduli. The surfaces of the discs of inflamed TMJs became rough and porous due to the loss of the superficial gel-like stratum, with many collagen fibers exposed and degradation of the sub-superficial collagen fibrils. Our results suggested that chronic inflammation of TMJ could lead to deterioration of mechanical properties and alteration of disc ultrastructure, which might contribute to TMJ disc displacement.

Prevalence of disc displacement of various severities among young preorthodontic population: a magnetic resonance imaging study

PURPOSE

There has been no study on the prevalence of disc displacement (DD) of different levels in children and adolescents with adequate sample size using magnetic resonance images (MRIs). This retrospective cross-sectional study was designed to investigate the relationship between increasing age and the prevalence of DD of various severities in a young preorthodontic population.

MATERIALS AND METHODS

Of 199 preorthodontic patients aged 6 to 15 years visiting a private orthodontic office for initial examination, 153 patients with signs and symptoms of temporomandibular joint (TMJ) disorders had MRIs of their TMJs taken for further evaluation. Of those, 302 TMJs from 151 patients' MRIs of diagnostic quality were divided into three age groups (I: 6 to 9, II: 10 to 12, and III: 13 to 15 years). DD of each patient was categorized based on its severity from stage 0 (normal) to stage 4 (total DD without reduction). The distribution of DD stages in each age group was plotted on a line graph and statistically analyzed for intergroup comparison.

RESULTS

A graphical representation of the results clearly demonstrated a trend for higher occurrence of more advanced DD with an increase in age. No gender difference was observed. Statistical analysis showed that DD was significantly more advanced in group II than group I (p < 0.01) and group III than group I (p < 0.01).

CONCLUSIONS

The study revealed a high prevalence of DD in the young preorthodontic population and significant increase in the proportion of patients with more advanced stages of DD in older patients.

Influence of defective complete dentures renewal on TMD; an MRI and clinical controlled prospective study

BACKGROUND

The influence of complete denture occlusion on temporomandibular disorder (TMD) is controversial. Some studies found that defective occlusion contributes to the development of TMD, while others found no correlation.

OBJECTIVE

This prospective controlled study evaluated the relationship between renewal of old defective complete dentures and TMD as evidenced both by clinical examination and magnetic resonance imaging (MRI) findings.

MATERIALS AND METHODS

The study included 25 complete denture patients with signs and symptoms of TMD and 21 asymptomatic controls. Clicking was a common finding in all symptomatic joints. All selected participants needed complete denture renewal. MRI and clinical assessment following research diagnostic criteria for TMD guidelines (RDC/TMD) were carried out at baseline and 2 years after new complete denture insertion. Temporomandibular joint (TMJ) pain, muscle pain, clicking and movement limitation were the assessed signs and symptoms. MRIs were conducted to evaluate the TMJs for disc displacement, disc morphology and joint effusion.

RESULTS

Complete denture renewal significantly improved the signs and symptoms of TMD in symptomatic group (p < 0.01). Only in the symptomatic group, treatment resulted in a significant increase in joints displaying superior (normal) disc position (symptomatic p < 0.001; asymptomatic p = 0.157). New dentures did not affect disc morphology in both groups (p = 0.5 for both groups) but significantly reduced joint effusion in the symptomatic group (symptomatic p < 0.001; asymptomatic p = 0.5). Relationship between clinical and MRI findings was not one to one.

CONCLUSIONS

New complete dentures had a positive impact on TMD signs and symptoms, disc position and joint effusion but not on disc morphology.

Joint disorder: nonreducing disc displacement with mouth opening limitation - report of a case

The internal derangement of the temporomandibular joint (TMJ) represents 8% of all cases of temporomandibular disorders (TMD) posing difficulties to establish an accurate diagnosis and treatment because of its low prevalence. This article presents the case of an 18-year-old Caucasian female patient who came to our Orofacial Pain and TMD Outpatient Service with complaints of intense pain on the right TMJ and limitation of mouth opening (maximum interincisal opening of 29 mm) with deviation to right, which she had been experiencing for the past 3 years. After a detailed clinical interview, a diagnosis hypothesis of nonreducing disc displacement with mouth opening limitation was established. The proposed treatment consisted of intra-joint infiltration with anesthetic in the right TMJ followed by jaw manipulation to recapture the articular disc, which was impeding the complete translation movement of the affected TMJ. After jaw manipulation, a new evaluation was done and showed the re-establishment of jaw dynamics with mouth opening and closing without deviation to the right side, clicking, opening limitation or pain. The patient was followed up at 6 months intervals. Two years after treatment, the patient was reevaluated and her mandibular range of motion without aid increased to 54 mm with no clicking, deviation to right, trismus or pain on the TMJ, indicating success of the treatment approach without recurrence of the pathology.

Temporomandibular joint sounds and disc dislocations incidence after orotracheal intubation

The aim of this study was to analyze the temporomandibular joint (TMJ) disc displacement and articular sounds incidence after orotracheal intubation. A prospective cohort study was conducted in the Hospital Universitário do Oeste do Paraná (HUOP), in Cascavel, Brazil. 100 patients (aged 14–74 years, mean 44 years), 34 male and 66 female, in need of surgical procedure with orotracheal intubation were evaluated. The anterior disc displacement with reduction incidence and the nonclassifiable sounds incidence by the Research Diagnostic Criteria Axis I was evaluated in all patients after orotracheal intubation. The patients was evaluated one day before and until two days after the procedure. Eight percent present with anterior disc displacement with reduction and 10% presented nonclassifiable sounds after the orotracheal intubation. There was no correlation of any kind regarding gender related influence in the incidence of disc dislocations (P = 0.2591) and TMJ sounds (P = 0.487). Although anterior disc dislocations and TMJ sounds after anesthetic with orotracheal intubation presented a low incidence (8%–10%), it is recommended that the evaluation of TMJ signs and symptoms be done before the anesthetic procedure to take care with susceptible patients manipulation.