OBJECTIVE: The objective of this study was to analyze the relationship between maxillomandibular characteristics and the severity of temporomandibular disc displacement in female patients with a skeletal class III (SKIII) pattern.
METHODS: Fifty-seven samples were included in the study. The evaluation of articular disc conditions was conducted using magnetic resonance imaging, while 25 cephalometric variables from lateral and postero-anterior (P-A) cephalograms were measured to determine their maxillomandibular characteristics. The samples were categorized into three groups based on the articular disc conditions: (1) normal disc position (NDP), (2) disc displacement with reduction (DDwR), and (3) disc displacement without reduction (DDwoR). The relationship between the maxillomandibular characteristics and disc conditions was examined through both basic statistical analysis and multivariate analysis using principal component analysis (PCA).
RESULTS: The Kruskal-Wallis and Dunn-Bonferroni tests revealed a significant difference between the groups in terms of the deviation of mandibular characteristics observed on the P-A cephalogram. The DDwoR group exhibited significantly larger menton deviation, ramal height asymmetry index, and total mandibular length asymmetry index compared to the NDP and DDwR groups. Moreover, the PCA successfully extracted all cephalometric variables into eight principal components. Among them, only the principal component related to mandibular asymmetry was able to differentiate the SKIII samples with DDwoR from the other groups.
CONCLUSIONS: The findings of this study highlight a significant relationship between mandibular asymmetry and the severity of disc displacement, particularly DDwoR, in female patients with a SKIII pattern.

OBJECTIVE: This pilot morphological study aimed to investigate the association between anterior disc displacement (ADD) and the status of the mandibular condyle and articular fossa.
METHODS: Thirty-four patients were divided into a normal articular disc position group and an ADD with and without reduction group. Images reconstructed were used to determine multiple group comparisons of these three different types of disc position, and the diagnostic efficacy for the morphological parameters with significant group difference was analyzed to assess.
RESULTS: The condylar volume (CV), condylar superficial area (CSA), superior joint space (SJS), and medial joint space (MJS) all exhibited obvious changes (P < 0.05). Additionally, they all had a reliable diagnostic accuracy in differentiating between normal disc position and ADD with an AUC value from 0.723 to 0.858. Among them, the CV, SJS, and MJS (P < 0.05) had a significantly positive impact on the groups by analysis of multivariate logistic ordinal regression model.
CONCLUSIONS: The CV, CSA, SJS, and MJS are significantly associated with different disc displacement types. The condyle in ADD exhibited altered dimensions. These could be promising biometric markers for assessing ADD.
CONCLUSIONS: The morphological changes of mandibular condyle and glenoid fossa were significantly influenced by the status of disc displacement, and condyles with disc displacement had three-dimensionally altered condylar dimensions, irrespective of age and sex.

The objective of the study is to determine the role of Lateral Pterygoid Muscle LPM in the articular disc displacement ADD, which is considered controversial due to the variations in the pattern of insertion of the Superior Lateral Pterygoid Muscle SPLM.
It is well understood that the superior head of the lateral pterygoid muscle has only a single insertion pattern among individuals, in which the muscle is attached to the articular disc and capsule. However, recent findings in many studies have shown a noticeable variation in the insertion pattern of the upper LPM.
MRI examinations were collected at King Faisal Specialist Hospital & Research Centre, Riyadh, Saudi Arabia. Scans of 61 patients (41 females, 20 males; mean age 33 years old) with symptoms of temporomandibular dysfunction were reviewed retrospectively. The direction of their articular disc displacement was evaluated through sagittal and coronal views in both open and closed mouth positions.
There was no statistical significance found between the LPM attachment types and TMJ disc position. The chi-square test also showed no significant difference between the type of LPM attachment and the condylar location. Forty-five percent of the articular discs were located between the articular eminence and the glenoid fossa. The majority of the disc displacement was in the anterior direction.
There was no statistically significant association found between the type of LPM attachments and the direction of disc displacement.

OBJECTIVE: Magnetic resonance imaging (MRI) is the method of choice for examining soft-tissue pathology of the temporomandibular joint (TMJ). MRI shows a high spatial resolution with accuracy for the identification of internal derangement. Tasaki developed a classification system for disc displacement in the TMJ, identifying eight different types of disc displacements in addition to the superior disc position. This study aims to test the ability of electrosonography (ESG) in discriminating different kinds of disc displacement according to the disc position criteria proposed, comparing the ESG results with those obtained by MRI.
METHODS: Twenty-seven patients were selected from an initial group of 50 patients with articular disc displacement, selected by means of clinical examinations, according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) and who had both MRI and ESG studies performed. For each patient and for each peak in ESG, both in the opening and closing movements, three different parts of the sound were analyzed. The frequency (Hz) and the mean amplitude (μV) of the sounds were calculated in the three analyzed windows. Afterwards, gathering the data for the Tasaki\'s classes and dividing opening and closing sounds, the number of peaks was calculated, as well as average and standard deviations for both the Hz and µV.
RESULTS: The peak frequency shows significant differences between different disc positions during the first and second third of the opening phase and during the first third of the closing phase. The peak amplitude shows significant differences between different disc positions during all of the opening and closing phases.
CONCLUSIONS: Although limited by sample size, the present study shows the presence of different sounds with different Hzs and μVs associated with different disc positions that were recorded with ESG.