Preoperative and postoperative assessment of temporal and masseter muscle size with magnetic resonance imaging in patients undergoing unilateral temporomandibular joint surgery

Intraobserver reliability and validity of a single ultrasonic measurement of the lateral condyle-capsule distance in the temporomandibular joint

PURPOSE

The purpose of the study was to examine the reliability and validity of a single lateral condyle-capsule distance (LCCD) measurement while saving on economic costs and clinical resources.

METHODS

A longitudinal test-retest design was used to assess the reliability and validity of single-examiner measures over 72 TMJ sonographic analyses. Intraclass correlation coefficients (ICC) and a Bland-Altman plot were used to study reliability and validity, comparing the first measurement of the LCCD to the mean of 3 measurements taken one week later by the same examiner.

RESULTS

ICC show intraobserver reliability of 0.981, 95% confidence intervals (CI) of 0.969 to 0.988. The mean difference between the ultrasound measurements is 0.019 mm (95% CI 0.0005-0.0383) with a standard deviation of 0.080 mm, demonstrating robust validity. The 95% Limits of Agreement (LoA) are - 0.138 for the lower limit and 0.177 for the upper. Mean relative error is 0.009 mm.

CONCLUSION

Intraobserver reliability of a trained examiner is very high in the single measurement of the LCCD and validity is significant compared to more complex methods. The risk of bias is low since the mean of three LCCD measurements is calculated as opposed to recording only one single measurement.

MRI of Temporomandibular Joint Disorders: A Comparative Study of 0.55 T and 1.5 T MRI

OBJECTIVES

Temporomandibular disorders (TMDs) are common and may cause persistent functional limitations and pain. Magnetic resonance imaging (MRI) at 1.5 and 3 T is commonly applied for the evaluation of the temporomandibular joint (TMJ). No evidence is available regarding the feasibility of modern low-field MRI for the assessment of TMDs. The objective of this prospective study was to evaluate the image quality (IQ) of 0.55 T MRI in direct comparison with 1.5 T MRI.

MATERIALS AND METHODS

Seventeen patients (34 TMJs) with suspected intraarticular TMDs were enrolled, and both 0.55 and 1.5 T MRI were performed on the same day. Two senior readers independently evaluated the IQ focusing on the conspicuity of disc morphology (DM), disc position (DP), and osseous joint morphology (OJM) for each joint. We analyzed the IQ and degree of artifacts using a 4-point Likert scale (LS) at both field strengths. A fully sufficient IQ was defined as an LS score of ≥3. Nonparametric Wilcoxon test for related samples was used for statistical comparison.

RESULTS

The median IQ for the DM and OJM at 0.55 T was inferior to that at 1.5 T (DM: 3 [interquartile range {IQR}, 3-4] vs 4 [IQR, 4-4]; OJM: 3 [IQR, 3-4] vs 4 [IQR 4-4]; each P < 0.001). For DP, the IQ was comparable (4 [IQR 3-4] vs 4 [IQR 4-4]; P > 0.05). A sufficient diagnostic IQ was maintained for the DM, DP, and OJM in 92% of the cases at 0.55 T and 100% at 1.5 T. Minor image artifacts (LS score of ≥3) were more prevalent at 0.55 T (29%) than at 1.5 T (12%).

CONCLUSIONS

Magnetic resonance imaging of the TMJ at 0.55 T yields a lower IQ than does MRI at 1.5 T but maintains sufficient diagnostic confidence in the majority of patients. Further improvements are needed for reliable clinical application.

Clinical Manifestations, Imaging Features, and Pathogenic/Prognostic Risk Factors for Temporomandibular Disorders (TMD): A Case-Control Study Based on Psychogenic Factors of Patients

Objective. To survey the clinical manifestations and imaging features of temporomandibular disorders (TMD) and analyze the risk factors for pathogenesis/prognosis through a case-control study based on psychogenic factors of patients. Methods. According to the inclusion criteria, 200 adult patients were randomly enrolled from the maxillofacial department of our hospital from January 2020 to May 2021, including 100 patients with TMD as the study group and 100 healthy patients as the control group. The study group can be assigned into four subgroups according to their clinical manifestations: (1) articular area or/and masticatory muscle pain group, (2) mandibular movement abnormality group, (3) joint murmur group, and (4) two or more symptom groups. Based on the study of psychogenic factors of patients, the clinical manifestations and imaging features of TMD were determined, and the risk factors for pathogenesis/prognosis were analyzed. Results. The distribution of psychological status in the TMD group was higher than that in the control group ( $P<0.05$ ). The distribution of anxiety, depression, and somatic symptoms in the TMD group was significantly different from that in the control group ( $P<0.05$ ). Anxiety, depression, and somatic symptoms were the risk factors for TMD. Compared with the control group, the incidence of abnormal MRI images in patients with temporomandibular disorders was significantly different ( $P<0.05$ ). There were significant differences in psychological status (anxiety, depression, and somatic symptoms) among the three groups ( $P<0.05$ ). Anxiety, depression, and somatic symptoms were the risk factors for abnormal mandibular movement and joint tremor and murmur ( $P<0.05$ ). Somatic symptoms were the risk factors for various clinical symptoms of TMD ( $P<0.05$ ). Depression was the risk factor for pain ( $P<0.05$ ). Conclusion. In patients with TMD, MRI can early identify disc abnormalities and other related imaging features, which is helpful for more comprehensive clinical evaluation and treatment of TMD patients. There exhibits no significant difference in psychological status (anxiety, depression, and somatic symptoms) of patients with different clinical symptoms, and abnormal psychological status may be one of the risk factors leading to different clinical symptoms and development of different types of TMD patients.

Imaging temporomandibular disorders: Reliability of a novel MRI-based scoring system

The aim of this study was to assess the inter- and intrarater reliability of a recently proposed scoring system for temporomandibular disorders (TMD), based upon radiological findings from magnetic resonance imaging (MRI). Patients with clinically suspected uni- or bilateral TMD, and subsequently conducted MRI examination of both temporomandibular joints, were included in this study. MRI data were independently evaluated by two experienced radiologists according to the DLJ scoring system proposed by Wurm et al., which includes assessment of the following categories: articular disk (prefix 'D'), direction of disk luxation (prefix 'L'), and osseous joint alterations (prefix 'J'). 60 patients (49 female and 11 male) were eligible for analysis. No significant differences were found between both observers regarding 'D' and 'L' scores (p = 0.13 and p = 0.59, respectively). Significant differences were found for the assessment of subtle osseous changes ('J0' category: p = 0.041; 'J1' category: p = 0.018). Almost perfect intra- and interrater agreements were found for 'D' and 'L' categories (intrarater and interrater agreements for 'D': κ = 0.92 and κ = 0.84, respectively; intrarater and interrater agreements for 'L': κ = 0.93 and κ = 0.89, respectively). However, the assessment of 'J' categories revealed only moderate interrater agreement (κ = 0.49). The DLJ scoring system based upon MRI findings is feasible for routine clinical TMD assessment, and may help to simplify interdisciplinary communication between radiologists and clinicians.