Effect of sagittal split ramus osteotomy on morphologic parameters of temporomandibular joint in patients with mandibular prognathism

Temporomandibular joint stress analysis of patients with different mandibular deformities during unilateral molar occlusion

Mandibular prognathism, retrusion and deviation are common mandibular deformities. They can lead to functional and aesthetic problems due to their important role in the oral system. Different from other occlusions, unilateral molar occlusion often occurs during mastication, which has a deep impact on the functions of temporomandibular joints (TMJs). Therefore, the study of unilateral molar occlusion is of great importance and significance to the daily life of patients with mandibular deformities. A total of 35 individuals were involved in this study, including 11 asymptomatic subjects, 10 patients with mandibular prognathism, 5 patients with mandibular retrusion and 9 patients with mandibular deviation. Finite element (FE) models corresponding to the unilateral molar occlusion were constructed. During unilateral molar occlusion, mandibular deformity increases the pressure on the condyle and articular disc. Compared with mandibular protrusion or retraction, facial asymmetry will significantly increase the stress of TMJ. Chewing on the non-deviated side also will lead to higher stress in the TMJ of patients with mandibular deviation. Therefore, patients with mandibular deviation have the highest risk of temporomandibular disorder (TMD), and it is recommended that patients with mandibular deviation chew bilaterally or with the deviated side.

Morphological analysis of the temporomandibular joint in patients with anterior disc displacement

This study aims to investigate the morphological characteristics of the temporomandibular joint (TMJ) in the patients with anterior disc displacement with reduction (ADDwR) and the alterations after occlusal splint treatment. Thirty ADDwR patients and ten asymptomatic subjects were recruited. Thirteen parameters were adopted, along with automatic computation and presentation of the joint space to characterize the TMJ morphologies. Statistical results showed that morphological discrepancies between the patients and the asymptomatic subjects were ubiquitous. The adjustment of condyle position through occlusal splint treatment can result in joint spaces widening and has positive effects on mitigating the conditions of ADDwR.

Morphometric evaluation of the temporomandibular joint on cone-beam computed tomography

INTRODUCTION

Evaluation of the temporomandibular joint (TMJ) pathologies with cone-beam computed tomography (CBCT) provides essential information about the bone structures of the TMJ. It is important to know the normal reference range when defining these pathologies. The aim of this study is to examine the morphometric and morphologic analyses of the bone structures of TMJ on the CBCT images in detail according to age, gender, and joint side.

MATERIAL AND METHODS

A total of 35 parameters related to the condylar process, articular tubercle, mandibular fossa, ramus of mandible, and joint space were examined on the CBCT images. These parameters were compared with the joint sides and gender, and correlated with age.

RESULTS

Thirty-five parameters were evaluated. A statistically significant difference was found between genders in 22 parameters and joint sides in 6 parameters. When the correlation of parameters with age was examined; it was found that there was a very weak positive relationship in nine parameters, a weak positive relationship in one parameter, and a very weak relationship in the negative direction in two parameters.

CONCLUSION

In this study, the condylar process, articular tubercle, mandibular fossa, ramus of mandible, and joint spaces, which are usually examined separately in the literature, were examined, and the normal reference range was determined for all these parameters. We think that these normal reference ranges will be useful for researchers interested in TMJ pathologies.