3D printed versus milled stabilization splints for the management of bruxism and temporomandibular disorders: study protocol for a randomized prospective single-blinded crossover trial.

BACKGROUND: Nowadays, stabilization splints for the management of bruxism and temporomandibular disorders (TMD) can be produced utilizing a digital workflow comprising a digital impression of the teeth, digital splint design, and computer-aided manufacturing of the splints. The latter is usually a milling process, however, more recently 3D printing gained popularity due to its better cost and time efficiency. It remains unknown whether 3D printed stabilization splints are inferior to milled splints regarding clinical outcomes. METHODS: This clinical trial assesses the non-inferiority of 3D printed occlusal splints compared to milled occlusal splints in a monocentric prospective randomized single-blinded crossover trial with two cohorts. One cohort includes 20 participants with bruxism, the other 20 participants with pain-related TMD, i.e., myalgia, myofascial pain, or arthralgia of the jaw muscles/the temporomandibular joint(s) diagnosed according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD). Michigan-type stabilization splints are fabricated in a digital workflow by milling or 3D printing using CE-marked materials within their intended purpose. The participants wear a milled and a 3D printed splint in a randomized order for 3 months each, with follow-up visits after 2 weeks and 3 months. Investigated outcome parameters are oral health-related quality of life (OHRQoL) evaluated by the Oral Health Impact Profile (OHIP-G14), participant satisfaction as rated on a visual analog scale, therapeutic efficacy, and technical result of the splints. In this context, therapeutic efficacy means antagonist wear and-in the TMD group-reduction of pain/disability assessed by the Graded Chronic Pain Scale (GCPS v2.0) and clinical assessment following the DC/TMD standard, while technical outcome measures splint fit, wear and fracture rate. DISCUSSION: The trial will provide important information on the clinical outcome of 3D printed stabilization splints in comparison to milled splints and will, therefore, enable an evidence-based decision in favor of or against a manufacturing process. This, in turn, will guarantee for a maximum of the patient's OHRQoL during splint therapy, therapeutic efficacy, and longevity of the splints. TRIAL REGISTRATION: German Clinical Trials Register (DRKS) DRKS00033904. Registered on March 15, 2024.

Clinical decision of centric relation.

Centric relation (CR) was used in the complete dentures for edentulous jaws firstly. Then, CR was gradually applied in the clinical diagnosis and treatment of dentate jaws. Regarding the application of CR in dentate jaws, there are many doubts about its rationality. For instance, should CR be the core of diagnosis and treatment of temporomandibular disorders? Should CR be used as the jaw position of establishing occlusion in occlusal reconstruction? Should CR serve as the target jaw position in orthodontic treatment? Meanwhile, varieties of CR clinical applications are objective. According to the existing evidence, this paper summarizes the applicable conditions of several main clinical situations with little controversy. We preliminarily put forward the decision tree for the clinical application of CR, which can be used as a reference in clinical practice.

Automatic prediction of obstructive sleep apnea in patients with temporomandibular disorder based on multidata and machine learning.

Obstructive sleep apnea (OSA) is closely associated with the development and chronicity of temporomandibular disorder (TMD). Given the intricate pathophysiology of both OSA and TMD, comprehensive diagnostic approaches are crucial. This study aimed to develop an automatic prediction model utilizing multimodal data to diagnose OSA among TMD patients. We collected a range of multimodal data, including clinical characteristics, portable polysomnography, X-ray, and MRI data, from 55 TMD patients who reported sleep problems. This data was then analyzed using advanced machine learning techniques. Three-dimensional VGG16 and logistic regression models were used to identify significant predictors. Approximately 53% (29 out of 55) of TMD patients had OSA. Performance accuracy was evaluated using logistic regression, multilayer perceptron, and area under the curve (AUC) scores. OSA prediction accuracy in TMD patients was 80.00-91.43%. When MRI data were added to the algorithm, the AUC score increased to 1.00, indicating excellent capability. Only the obstructive apnea index was statistically significant in predicting OSA in TMD patients, with a threshold of 4.25 events/h. The learned features of the convolutional neural network were visualized as a heatmap using a gradient-weighted class activation mapping algorithm, revealing that it focuses on differential anatomical parameters depending on the absence or presence of OSA. In OSA-positive cases, the nasopharynx, oropharynx, uvula, larynx, epiglottis, and brain region were recognized, whereas in OSA-negative cases, the tongue, nose, nasal turbinate, and hyoid bone were recognized. Prediction accuracy and heat map analyses support the plausibility and usefulness of this artificial intelligence-based OSA diagnosis and prediction model in TMD patients, providing a deeper understanding of regions distinguishing between OSA and non-OSA.

ETIOLOGY, DIAGNOSIS AND TREATMENT OF MUSCLE-ARTICULAR DYSFUNCTION OF THE TEMPOROMANDIBULAR JOINT IN ADOLESCENCE.

Etiologic and pathogenetic aspects cause the most contentious issue in the study of temporomandibular joint (TMJ) syndrome in childhood and adolescence. Some researchers have linked the emergence of this group of diseases with abnormal occlusion, others have more emphasis on the age characteristics of a growing organism, or rather on a number of morphological and psychomotor processes arising and ending at puberty and cause physiological abnormalities in the growing organism. The aim of the study was to improve the method of complex treatment of TMJ dysfunction in adolescence by exploring its development factors with early diagnosis methods. MATERIAL AND METHODS: We have examined by clinical and radiological methods 33 patients with TMJ syndrome disorder between the ages of 11 to 18 years, 20 of them (60.6%) girls and 13 (39.4%) boys. All examined patients complained of the presence of clicks in the joint when they open mouth widely, irregular movement of the lower jaw when opening the mouth, the periodic occurrence of unilateral pain in the joint and the ear, increasing when taking rigid and solid food, which allowed us to establish the diagnosis of the TMJ syndrome. A clinical study has focused on the survey of patients, and in some cases their parents, in order to study carefully the history of life and disease, and the patient's complaints. We have found out the factors predisposing to the disease: the presence of various bad habits, family history, trauma of the lower jaw and TMJ, errors in orthodontic treatment. RESULTS: The data obtained showed that 16 (48.5%) patients had a history revealed various factors that contribute to the TMJ syndrome. The presence of various bad habits was about 38%. In addition, 13 (39.4%) patients reported the presence of emotional stress. The presence of orthodontic pathology was determined in 26 (78.8%) patients, 7 (21.2%) patients had no dentofacial disorders was not determined. The most common symptom, occurring in 27 (81.8%) patients was clicking in the joint with one or two sides, as well as excessive excursion of articular heads, occurring in 17 (51.5%) patients. A distinctive feature of TMJ syndrome manifestations in children and adolescents is relatively rare, in contrast to adults, the appearance of symptoms: pain when opening the mouth wide detected only 7 (21.2%) patients; pain in the joints - 8 (24.2%) patients; pain in the masticatory muscles - 6 (18.2%) patients. CONCLUSIONS: Based on the above, the etiological factors of musculo-articular dysfunction of the TMJ in adolescence can be not only dental anomalies, but also the presence of bad habits, disproportions in the growth of the bone and muscular skeleton and hypokinetic states caused by psychophysiological responses to chronic stress. Accordingly, treatment of patients with this pathology should be comprehensive and include not only treatment of the dental system, but also be aimed at the uniform development of the musculoskeletal system in children and at eliminating bad habits and chronic stress factors.

Anatomical variations of the lateral pterygoid plate and their implications for temporomandibular disorders: A CBCT study.

OBJECTIVE: TMD is a multifaceted condition with various contributing factors, but the actual impact of the lateral pterygoid plate on the development of TMD remains uncertain. This research aims to investigate the relationship between anatomical variations of the lateral pterygoid plate (LPP), including its angle and proximity to the condyle, and the prevalence of temporomandibular disorders (TMD), to improve diagnostic accuracy and therapeutic approaches for TMD. MATERIALS & METHODS: A retrospective analysis was conducted on 189 Cone Beam Computed Tomography (CBCT) images of individuals aged 18 to 45. Inclusion criteria were based on definitive diagnoses of degenerative joint disease, excluding individuals with orthodontic treatments, injuries, or craniofacial disorders.Participants were divided into TMD and control groups using standardized DC/TMD protocols for assessment. A radiologist, blinded to the patient's clinical status, then analyzed the CBCT images. LPP dimensions, angles, and condyle distances were measured using OnDemand 3D Imaging Software. RESULTS: The study found a statistically significant higher average LPP length in females compared to males (right LPP p < 0,001, left LPP p = 0,004), with no significant differences in LPP-condyle distances and angles between genders. Comparing the TMD and control groups revealed a positive correlation between lateral plate angles and TMJ disorders (p = 0,044), suggesting a potential biomechanical linkage. CONCLUSION: Conclusively, the study challenges the assumption that LPP anatomical variations significantly impact TMD while underscoring a potential link between LPP angle and TMD. The novel insight into the potential role of the LPP angle in TMD provides a new direction for research and clinical practice, emphasizing the importance of considering subtle anatomical differences in the management of TMD.

Cepstral Analysis of Voice in Patients With Temporomandibular Disorders.

OBJECTIVES: This study aimed to assess the voice quality of patients with temporomandibular disorders (TMDs) compared with healthy subjects using cepstral analysis and investigate the relationship between the TMD severity and the values of cepstral analysis. METHODS: Subjects who met the inclusion criteria completed a general health questionnaire and the Fonseca Anamnestic Index. Patients who had TMDs with FAI were subjected to an examination based on the Diagnostic Criteria for Temporomandibular Disorders. The final sample included 65 subjects, 31 TMDs patients (with a mean age ± standard deviation of 36.64 ± 13.67 years), and 34 healthy individuals in the control group (with a mean age ± standard deviation of 30.35 ± 7.78 years). Cepstral Peak Prominence (CPP) and Smoothened Cepstral Peak Prominence (CPPS) of a sustained vowel and connected speech were computed using Praat software. RESULTS: TMD patients indicated lower cepstral values and lower voice quality compared to the control group. Significant differences were found between TMD and control groups for all cepstral parameters (P < .001) and cepstral measurements showed a moderate to strong negative correlation with TMD severity (P < .001, rho = -0.57 to -0.88). CONCLUSION: The outcomes of the present study indicate that cepstral analysis can accurately distinguish the reduced voice quality of TMD patients from normal voice.

Can ChatGPT-4o provide new systematic review ideas to oral and maxillofacial surgeons?

OBJECTIVE: This study aims to evaluate the capacity of ChatGPT-4o to generate new systematic review ideas in the field of oral and maxillofacial surgery. The data obtained from this study will provide evidence-based information to oral and maxillofacial surgeons regarding the academic use of GPT-4o. MATERIALS AND METHODS: ChatGPT-4o was asked to provide four previously unpublished systematic review ideas each for the topics of impacted third molars, dental implants, orthognathic surgery, and temporomandibular disorders. A literature search was conducted in the PubMed database to check if the ideas generated by GPT-4o had been previously published, and the search results were compared with the ideas generated by the AI. RESULTS: The PubMed database search resulted in a total of 871 publications, with 37 publications found to be related to the topics generated by GPT-4o after the first and second screening. Out of the 16 publication ideas generated by GPT-4o, 9 (56.25 %) were determined to be previously unexplored according to the PubMed database search. There was no statistically significant relationship between the presence of ChatGPT's suggestions in PubMed and the subject areas of the studies. CONCLUSION: ChatGPT-4o has a high potential to be used as a valuable tool for suggesting systematic review topics in oral and maxillofacial surgery. Additionally, this tool can assist researchers not only in proposing publication ideas but also in developing the methodology of the study.

High prevalence of orofacial pain in juvenile fibromyalgia as detected by a novel tool specifically devised for children and adolescents.

OBJECTIVES: To examine the prevalence of temporomandibular disorders (TMD) in patients with juvenile fibromyalgia syndrome (JFS) and identify TMD characteristics specifically associated to JFS. METHODS: Signs and symptoms of TMD were assessed using a novel clinical tool specifically devised for children that consists of: 1. a self-report multiple-choice questionnaire; 2. a protocol for the clinical examination of the orofacial region. Multivariate logistic regression model was used to identify TMD features associated with JFS. RESULTS: Thirty JFS patients (median age 15.5 years) and 45 healthy controls (median age 15.0 years) were included in this cross-sectional study. Orofacial pain was reported by 26 of 30 JFS patients (86.7%) and by 3 of 45 controls (6.7%; p<0.001). Pain on TMJ palpation was present in 18 of 30 JFS patients (60%) and in 5 of 45 controls (11.1%; p<0.001). Median values of maximum spontaneous mouth opening, voluntary active opening and assisted passive opening were significantly higher in JFS patients than in controls. On multiple regression analysis spontaneous orofacial pain (OR: 21.0; p=0.005), diffuse tenderness on palpation of the masticatory muscles (OR: 14.9; p=0.026) and TMJ hypermobility (OR 1.42; p=0.008) were independently associated with JFS. CONCLUSIONS: The high prevalence of TMD in JFS highlights the need for a broader interdisciplinary evaluation of JFS patients. TMJ hypermobility, in addition to orofacial and masticatory muscle pain, is an important clue for the diagnosis of TMD in adolescents with JFS. Elucidating the link between these disorders will advance individualised management and improve treatment efficacy.

Evaluation of clinical impact of two types of Temporomandibular joint disc reduction and fixation.

OBJECTIVE: To evaluate the clinical effectiveness and stability of open suture versus micro-screw anchored disc reduction and fixation in treating disc displacement without reduction in the anterior temporomandibular joint. METHODS: A total of 38 patients (51 sides) with anterior disc displacement without reduction (ADDwR) of the TMJ treated in our hospital from August 2021 to January 2023 were selected, including 19 cases in group A (23 sides) treated with open temporomandibular joint disc reduction and anchorage, and 19 cases in group B (28 sides) treated with temporomandibular joint disc reduction and suture. The Magnetic Resonance Imaging (MRI) data of the two groups before and after operation were compared to evaluate the effective rate of articular disc reduction, the change of articular disc length, The Maximal Interincisal Opening (MIO) and Numeric Rating Scale (NRS) were measured before and after operation. RESULTS: In group A, the MRI effective rate 6 months after disc reduction was 95.65 % (22/23), the disc length gain was 1.74 mm, MIO was 40.32±5.067 mm, and NRS was 0.47±0.697. The MRI effective rate 6 months after disc reduction in group B was 100 % (28/28). The disc length gain was 1.78 mm, MIO was 41.58±3.746 mm, and NRS was 0.00. There was no significant difference between the two groups (P > 0.05). CONCLUSIONS: TMJ disc reduction and suture and open TMJ disc anchorage can effectively reduce the TMJ disc. The TMJ disc stability is high at 6 months after operation, and the pain and mouth opening can be improved, which is worthy of further promotion in clinical practice.

The relationship between the articular disc in magnetic resonance imaging and the condyle in cone beam computed tomography: A retrospective study.

BACKGROUND: The authors retrospectively studied the relationship between the morphology and position of the articular disc in magnetic resonance imaging (MRI) and the morphology and position of the condyle in cone beam computed tomography (CBCT), with the purpose for providing reference for clinical diagnosis and treatment of temporomandibular disorders (TMD). METHODS: Patients with both CBCT and MRI imaging data were studied retrospectively, excluding TMJ tumour, fracture, severe condylar morphological abnormalities, non-intercuspal position, and poor quality images. A total of 744 temporomandibular joints (TMJs) from 372 patients were included, with the mean age of 25.94±11.04Y (75 males and 297 females). T2-weighted image (T2WI) of MRI imagings were used to evaluate disc morphology and disc displacement, while CBCT was obtained to evaluate the condylar bone and sagittal condylar position. Data were analysed by Pearson Chi square test and Spearman correlation coefficient. RESULTS: THE DISTRIBUTION OF 744 TMJS IS AS FOLLOWS: 1) DISC MORPHOLOGY: contracture (37.1 %) > biconcave (32.9 %) > irregular (18.5 %) > lengthened (11.4 %); 2) disc position: ADDWoR (48.3 %) > NA (26.9 %) > ADDWR (21.6 %) > PDDWR (2.8 %) > PDDWoR (0.4 %); 3) condylar position: concentric (43.7 %) > posterior (37.6 %) > anterior (18.7 %); 4) condylar bone: normal (63.4 %)> abnormal (36.6 %). There were significant differences in the distribution of disc morphology and disc position between the sex (P < 0.05). There were significant differences in the distribution of disc position and condylar morphology amongst the age groups (P < 0.05). There were significant differences in the distribution of disc position, condylar position and condylar morphology amongst disc morphology (P < 0.05), and there were positive correlation between disc position(r = 0.703, P = 0.000), the score of condyle (r = 0.478, P = 0.000) and disc morphology respectively. There were significant differences in the distribution of disc position and condylar position amongst condylar morphology (P < 0.05). There was a positive correlation between disc position and condyle morphology (r = 0.413, P = 0.000), and a negative correlation between condyle position and condyle morphology (r=-0.152, P = 0.000). There were significant differences in the distribution of disc position amongst condylar position (P < 0.05), but there was no linear correlation (P = 0.159). CONCLUSIONS: The mutual distribution of disc morphology, disc position, condylar morphology and condylar position was statistically significant. Disc displacement did not necessarily lead to condylar bone changes, but 92.7 % TMJs with condylar bone abnormalities had disc displacement. TRIAL REGISTRATION: This study was retrospectively registered on 28/03/2022 and endorsed by the Ethics committee (LCYJ2022014).

Gout Arthritis of Temporomandibular Joint - A Rare Case Report and Review of Literature.

ABSTRACT: Gout is a metabolic disorder that leads to elevated serum uric acid levels and deposition of urate crystals in the joints. The disease is usually confined to the joint space and leads to pain and limitation of jaw opening. The case describes a 45-year-old female patient with a chief complaint of 'occasional pain in the left temporal muscle region'. The case disclosed a gout manifestation in the temporomandibular joint (TMJ) after physical and radiographic findings. Gout manifestation in the TMJ is an unusual presentation and a few reports in the English literature address the subject. Gout in the TMJ should be included as a differential diagnosis for joint disorders because of its rarity. A clinician may overlook gout involving the TMJ in the differential diagnosis of facial pain even when the patient has received a diagnosis of gout in other joints.

Telediagnosis as an effective tool for assessment temporomandibular disorders.

BACKGROUND: The use of communication technologies has allowed a substantial improvement in telediagnosis. OBJECTIVES: To evaluate the feasibility and diagnostic agreement of synchronous teleconsultation compared to physical standard examination for temporomandibular disorders (TMD) and orofacial pain. METHODS: Sixty-one patients (50 women, 11 men) with a mean age of 46.07 years referred to the Orofacial Pain Ambulatory Service (SAMDOF -UFPR) were evaluated remotely. They were then examined in person by another evaluator, blinded for the first evaluation. Data on the experience and level of satisfaction with the teleconsultation were also collected. RESULTS: For each type and subtype of TMD, diagnostic agreement values, sensitivity, specificity, positive predictive values and negative predictive values were calculated with a 95% confidence interval. 'Almost perfect' agreement was found for Myalgia (k = 0.915), Arthralgia (k = 0.863), disc displacement without reduction without limited opening (k = 0.955) and no TMD (k = 1.00). 'Substantial' agreement for the subtypes headache attributed to TMD (k = 0.761), disc displacement without reduction with limited opening (k = 0.659) and subluxation (k = 7.82). The diagnoses of local myalgia (k = 0.573), myofascial pain with referral (k = 0.524) and disc displacement with reduction (k = 0.563) obtained 'moderate' agreement. Degenerative joint disease (k = 0.170) and disc displacement with reduction with intermittent locking (k = 0.000) obtained 'weak' and 'no agreement', respectively. More than 90% of the participants were satisfied and reported no discomfort during the assessment, agreeing to participate in another teleconsultation. CONCLUSION: Synchronous teleconsultation proved to be feasible and presented adequate diagnostic agreement for the main painful TMDs, especially for the diagnosis of myalgia and arthralgia. This format was also well accepted among patients.

Implementing online learning of Diagnostic Criteria for the Temporomandibular Disorders (DC/TMD) protocol in undergraduate dental education.

INTRODUCTION: The Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) is part of the undergraduate dental curriculum. Online teaching has nowadays become common also in dentistry. OBJECTIVE: To compare undergraduate students' self-assessed ability and satisfaction with learning DC/TMD Axis I between traditional and online learning and to evaluate the possible gains of online teaching. MATERIAL AND METHODS: Third-year undergraduate dental students in 2018 (traditional learning, Group 1, n = 43/50) and in 2019 (online learning, Group 2, n = 34/50) at the University of Oulu, Finland evaluated their self-assessed ability and satisfaction with learning DC/TMD clinical examination and diagnostics on a 10-point scale. Additionally, those participating in online courses answered to two open-ended questions; Group 2 (n = 50) and another group from the University of Eastern Finland in 2019 and 2020 (n = 75, Group 3). Total of 105/125 students (84%) responded. Content analysis was used to open-ended responses. RESULTS: The online course reported significantly higher self-assessed ability in measurements (p = 0.004), identifying referred pain (p = 0.043) and statement for the diagnostics (p = 0.017) and also higher self-assessed satisfaction in measurements (p = 0.046). According to the content analysis, essential gains of online teaching were efficient learning, videos and exercises, and adjustability to own timetable. CONCLUSION: The online learning course can be considered as a good option for traditional learning of the DC/TMD protocol.

Investigating the effect of depression on clinical symptoms of temporomandibular disorder in young stressful men.

OBJECTIVES: The objective of this study was to investigate the relationship of the depression level with temporomandibular disorders (TMDs) in young conscripts as a population with chronic stresses. MATERIAL AND METHODS: A total number of 144 male conscripts with chronic stress and different levels of depression were assigned to four groups according to the Beck's Depression Inventory (BDI). The control group consisted of age-matched male conscripts without chronic stress. The diagnosis of TMD was made according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD). Data were analyzed using Mann-Whitney and chi-square tests. RESULTS: The participants with severe depression were significantly more susceptible to have TMD (p = .001) followed by the moderate depression, borderline clinical depression, mild mood disturbance, and control groups. The TMD diagnoses were more prevalent within depression groups compared with the control population (p = .01). CONCLUSIONS: The level of depression is directly associated with the presence of TMD in young men with chronic stress.

Comparison of Machine Learning Algorithms Fed with Mobility-Related and Baropodometric Measurements to Identify Temporomandibular Disorders.

Temporomandibular disorders (TMDs) refer to a group of conditions that affect the temporomandibular joint, causing pain and dysfunction in the jaw joint and related muscles. The diagnosis of TMDs typically involves clinical assessment through operator-based physical examination, a self-reported questionnaire and imaging studies. To objectivize the measurement of TMD, this study aims at investigating the feasibility of using machine-learning algorithms fed with data gathered from low-cost and portable instruments to identify the presence of TMD in adult subjects. Through this aim, the experimental protocol involved fifty participants, equally distributed between TMD and healthy subjects, acting as a control group. The diagnosis of TMD was performed by a skilled operator through the typical clinical scale. Participants underwent a baropodometric analysis by using a pressure matrix and the evaluation of the cervical mobility through inertial sensors. Nine machine-learning algorithms belonging to support vector machine, k-nearest neighbours and decision tree algorithms were compared. The k-nearest neighbours algorithm based on cosine distance was found to be the best performing, achieving performances of 0.94, 0.94 and 0.08 for the accuracy, F1-score and G-index, respectively. These findings open the possibility of using such methodology to support the diagnosis of TMDs in clinical environments.

[Growth disturbances of the temporomandibular joint: causes, diagnosis and treatment]. / Groeistoornissen van het kaakgewricht: oorzaken, diagnose en behandeling.

Growth disturbances of the temporomandibular Joint are characterized by mandibular asymmetry, sometimes with secondary maxillar disturbances. Although the clinical symptoms are sometimes quite severe, patients usually have no pain. There are several growth disturbances, but in this article we discuss three particular causes of facial asymmetry, namely hemimandibular growth defects; overdevelopment, underdevelopment and neoplasms of the mandibular joint. Hemimandibular overdevelopment (hyperplasia) is a growth disorder characterized by progressive asymmetry of the mandibula. Hemimandibular hypoplasia, on the other hand, is a growth disorder involving underdevelopment of the condyle mandibulae due to impingement of the growth center and ankylosing. A pronounced asymmetrical face can cause aesthetic problems and always requires diagnostics, because in addition to the hyperplasia and hypoplasia mentioned above, other causes can explain the asymmetry such as, for example, an osteoarthritis or even a tumor emanating from the base of the skull, mandibula or soft tissues.

[Imaging in temporomandibular joint disorders]. / Beeldvorming bij kaakgewrichtsstoornissen.

The temporomandibular joint is a unique and complex joint. Various imaging techniques have been developed to properly visualize this complex joint, such as conventional radiology, orthopantomography, CBCT and MRI. Imaging can contribute to the differential diagnosis of temporomandibular joint disorders. Common joint disorders are arthritis and internal derangement. Osseous changes of the temporomandibular joint can be clearly visualized with CBCT. MRI is superior for imaging the internal anatomy of the temporomandibular joint and is preferred in the context of internal derangement.

Reliability of an intraoral extension for intraoral palpation and assessment of mechanical sensitivity of the temporal tendon.

BACKGROUND: The temporal tendon is a structure often compromised in patients suffering from temporomandibular disorders (TMD), yet its intraoral location makes a standardised assessment difficult. OBJECTIVES: To evaluate the variability and accuracy to target force of a newly designed intraoral extension for a palpometer device (Palpeter, Sunstar Suisse) when compared to manual palpation, in addition to clinically assessing the mechanical sensitivity and referred sensations of the temporal tendon in healthy individuals. METHODS: Experiment 1: 12 individuals were asked to target on a scale 0.5, 1 and 2 kg, for 2 and 5 s by using five different methods (Palpeter, Palpeter with three different extension shapes and manual palpation). Experiment 2: 10 healthy participants were recruited for a randomised double-blinded assessment by applying pressure of 0.5, 1 and 2 kg to the right temporal tendon with the three extensions and manual palpation. Participants rated the intensity of their sensation/pain on a 0-50-100 numeric rating scale (NRS), unpleasantness on a 0-100 NRS, and if present, they rated and drew the location of referred sensations. Repeated measures analysis of variance (ANOVA) was used in both experiments to compare differences between palpation methods. Tukey's HSD tests were used for the post hoc comparisons, and p values below .05 were considered significant. RESULTS: Experiment 1: The extensions showed no significant differences between them regarding reliability and accuracy for all forces and durations (p > .05). The manual method was significantly less reliable and accurate when compared to the other methods (p < .05). Experiment 2: There were no significant differences between the Palpeter extensions regarding pain intensity or unpleasantness NRS scores (p > .05), but all the extensions had significantly increased pain intensity and unpleasantness when compared to manual palpation (p < .05). Similarly, the frequency of referred sensations was similar between extensions but increased when compared to manual palpation. CONCLUSIONS: The new Palpeter extensions proved to be significantly more accurate and have lower test-retest variability than the manual method in a non-clinical setting. Clinically, they showed no significant differences in NRS scores for pain intensity nor unpleasantness, with no major differences in referred sensations, making any of the extensions suitable for clinical testing of the temporal tendon in future studies.