Association Between Articular Eminence Structure and Joint Spaces in Temporomandibular Joints with Anterior Disc Displacement.

BACKGROUND AND AIMS: The association among the joint spaces, articular eminence morphology, and disc displacement is not well documented in the literature. This study aims to evaluate and compare the joint spaces and the articular eminence structure (eminence height [Eh] and inclination [Ei]) using cone-beam computed tomography (CBCT) of temporomandibular joints (TMJs) with anterior disc displacements and joints with normal disc position. METHODS: The study groups consisted of 75 TMJs of 39 patients. The disc status of TMJs was diagnosed with magnetic resonance imaging, and the measurements were performed on CBCT. Three groups, that is, normal disc position (NDP) group, anterior disc displacement with reduction (ADDWR) group, and anterior disc displacement without reduction (ADDWoR) group, were established. Anterior, superior, posterior joint spaces (AJS, SJS, and PJS, respectively), articular Eh, and articular Ei were measured. Statistical Package for the Social Sciences version 22 was used for statistical analysis. Shapiro-Wilk test was used to check the normality of data. Intergroup comparisons of categorical variables were assessed with Fisher-Freeman-Halton test. For comparison of continuous variables parameters, Mann-Whitney U test and Kruskal-Wallis test were used. Statistical significance level was determined as P < 0.05. RESULTS: Significant differences were not found in intergroup comparisons for PJS. However, the difference between groups was found to be significant for AJS, SJS, Eh, and Ei. Intergroup comparisons were performed for these parameters. No significant difference was found between the NDP group and the ADDWR group for AJS, SJS, Eh, and EI. The mean AJS, SJS, Eh, and Ei values in ADDWoR were found to be significantly lower compared to the corresponding values in both NDP and ADDWR groups. CONCLUSION: Decreased AJS and SJS when TMJ is evaluated with CBCT may be an indicator of ADDWoR. Authors suggest that narrowed articular Ei and reduced articular Eh can be one of the predisposing factors for anterior disc displacement.

Sonoelastographic evaluation of the masseter muscle before and after mandibular setback surgery.

AIMS: The purpose of this study is to compare the thickness and elasticity of the masseter muscle before and after orthognathic surgery in patients with class III skeletal deformity and to investigate the relationship between the sonographic changes in the masseter muscle and the amount of mandibular setback. SUBJECTS AND METHODS: The study group consisted of 14 patients with skeletal class III malocclusions who had orthognathic surgery. The control group consisted of 14 patients who had dental and skeletal class I occlusion. Muscle thickness measurements were performed with B-mode and high-frequency linear scanning probe of the ultrasound device. Elastography feature and muscle hardness ratio were obtained by applying compression and decompression on muscles at rest and during maximum contraction in the transverse plane. Patients were categorized into two groups according to the mandibular setback as <5 mm and ≥5 mm. RESULTS: The masseter muscle thickness after surgery was found statistically increased bilaterally in both at rest and during contraction for the study group (P < 0.05). No difference was found between preoperative orthognathic measurements and postoperative measurements for elasticity index ratio measurements (P > 0.05). CONCLUSION: We believe that in the present study important findings have been emphasized for further research aiming to investigate the possible relationship between masticatory alterations and surgical outcomes after orthognathic surgery.

An unusual case of multilocular Stafne bone cavity.

Stafne bone defects (SBDs) are asymptomatic lingual bone depressions of the lower jaw that are frequently caused by soft-tissue inclusion. The common variant of SBD exists at the third molar region of the mandible below the inferior dental canal is an and ovoid-shaped homogeneous well-defined radiolucency. In this report, an unusual occurrence of SBD with multilocular appearance is presented. Asymptomatic lingual bone defects may represent various radiographic features. Detailed radiographic evaluation with CT scans should be performed to differentiate SBDs from other pathologies.

Tetrafid mandibular condyle: a unique case report and review of the literature.

Morphological changes such as bifid and trifid mandibular condyle are rare entities. The aim of the present report is to describe a unique morphological variation of the mandibular condyle which has four separate condylar heads (tetrafid mandibular condyle) and to discuss clinical and radiological differential diagnosis of tetrafid mandibular condyle with advanced imaging techniques.