The Study On Morphology And Structure Of Temporomandibular Joint By CBCT For Angle ? Adult Patients

Objective:The aim of this research was to compare Angle ? malocclusion adult patients and Angle ? malocclusion volunteers effect on condylar position and morphological structure of temporomandibular joint (TMJ) using cone-beam computed tomograpty(CBCT). In order to adjust the condylar position in the temporomandibular joint fossa in orthodontic treatment. At the same time it will provide guidance for clinical diagnosis and treatment for Angle ? malocclusion patients with temporomandibular disorders.Methods:Section1 Sixty aged 18~3 2 years old Angle ? malocclusion adult patients selected as treatment groups in the Chinese PL A General Hospital from September 2015 to December 2016, Angle ?. and Angle ?2 each thirty cases. In addition to select thirty cases of Angle ? malocclusion adult patients of mild denture crowded as control group.All patients were scanned by CBCT and original images were reconstructed and measured using QR-NNT software. then determine the position of condyle in the glenoid fossa by Pullinger analysis methods. All three-dimensional images were measured three times by the same researcher so as to be calculated mean value, then data was analyzed by GraphPad Prism 6.0 software.Section 2 Using the removal maxillary bite plane to open the anterior teeth bite of the Angle ? malocclusion patients, aligned and leveling the mandibular dentition. After opening the anterior teeth bite, and the posterior teeth establish stable occlusion, all patients were scanned by CBCT again. Images were reconstructed with QR-NNT software and data was compared by GraphPad Prism 6.0 software.Results:Section 11. There were no statistically significant differences between the left and right structures of various malocclusions patients (P>0.05).2. There were significant differences in the horizontal angle, gradient of articular tubercle , length of condyle, long axis of condyle, width of glenoid fossa and superior and posterior joint space among three types of malocclusion (P<0.05). There were significant differences in the short axis of condylar between Angle ?1 and Angle ?2?Angle ? malocclusion (P<0.05). There were significant differences in the height of glenoid fossa between Angle ?2 and Angle ?1?Angle ? malocclusion (P<0.05).3. Most condyles of Angle I were concentrically positioned in the glenoid fossa; most condyles of Angle ?1 were anteriorly positioned and most ones of Angle ?2 were posteriorly positioned.Section 21. After opening the anterior teeth bite of the over bite Angle ? malocclusion, there were significant differences in the superior joint space and posterior joint space of Angle ?1 malocclusion (P<0.05). The anterior joint space was smaller, the superior and posterior joint space were bigger of Angle ?2 malocclusion, it has statistically difference(P<0.05).2. After opening the anterior teeth bite of the Angle ? malocclusion, the condylar position in the fossa has the trend of the forward.Conclusions:1. CBCT can be a normal examination method of craniofacial bone and TMJ, asymmetric structure of TMJ can be found by CBCT, although there may be no evident clinical symptoms2. The measurement method of TMJ morphological structure this research adopts was repeatable.3. Both sides of the TMJ morphological structure were basically symmetry in Angle ?and Angle ? malocclusion patients. Most condyles of Angle ? were concentrically positioned in the glenoid fossa; most condyles of Angle ?1 were anteriorly positioned and most ones of Angle ?2 were posteriorly positioned.4. After opening the anterior teeth bite of the Angle ? malocclusion, the condylar position in the fossa has the trend of the forward.