Evaluation of bone changes and range of motion of the Temporomandibular joint using cone beam computed tomography- a prospective cross sectional study

Background: The Temporomandibular joint (TMJ) is one of the most complex joints in the human body and is the area in which the mandible articulate with the cranium. Conventionally, the most commonly used radiographic methods for the evaluation of osseous changes of the TMJ include transcranial projection, transpharyngealprojection, tomography and panoramic radiography. With the introduction of Computed Tomography (CT), the osseous components of the TMJ can be viewed three dimensionally. Unfortunately, most CT units are large and expensive, and are not readily available to dentists. Cone Beam CT (CBCT) is a newly developed technique and because of its comparatively lower radiation dose and higher spatial resolution, it has been widely accepted and used for different diagnostic tasks in oral and maxillofacial region. Recent Studies have revealed that the CBCT is a reliable alternative to multislice CT for the assessment of the TMJ space and osseous changes. AIM: The aim of this study is to evaluate osseous changes and the range of motion of TMJ in Temporomandibular disorder using CBCT. Materials and Methods: A prospective cross sectional study has been conducted at Department of Oral Medicine and Radiology, private Dental Institution, Chennai. The study population will consist of 50 subjects (100TMJs) from 18-60 years of age. Using 3D reconstruction CBCT (ProMax 3D Machine), images obtained in both maximum intercuspation and maximum mouth opening position. Results: The Adjusted Logistic Regression model, age and gender showed no statistically significant association with the presence of bone changes. The Pearson X2 test showed that there was a statistically significant association with the presence of bone change in relation to condylar mobility of the Right TMJ (Right side p = 0.009; Left side p = 0.811). The results of the McNemar test showed that the proportions of TMJ bone changes showed no significant differences between the sides (p = 1.000). The range of motion proved to be increased demonstrating hypermobility in 35 patients in the right TMJs and 37 patients in the left TMJs. Hypomobility was seen in 4 Right TMJs and 2 Left TMJs. Conclusion: There is a high prevalence of degenerative bone alteration in TMJs, which is more frequent in women and mostly located in the condyle. The prevalence of degenerative bone changes occur at the young age group. There is significant correlation between condylar mobility and the presence of degenerative bony changes in TMJs.