Assessment of Temporomandibular Joint and Mandible in Image of Cone Beam Computed Tomography in Patients with Angle Class II and III Dentofacial Deformaties. Summary of the Doctoral Thesis

Abstract

Evaluation of mandibular and temporomandibular (TMJ) skeletal structures (the head of mandible and articular fossa) in orthodontic patients with dentofacial deformations is a significant factor for treatment planning and prediction of the treatment results` stability. The literature more often presents studies where data are achieved by analyzing the two-dimensional TMJ images of individuals from different groups of age with clinically different temporomandibular disorders and with different occlusal symptoms. There is not enough explored skeletal TMJ structure in patients with dentofacial deformations who need combined orthodontic and surgical treatment in the scientific literature. Lack of these data causes different and controversial beliefs about changes in TMJ skeletal structures. Wider opportunities to explore TMJ skeletal structures are provided by the development of new specific three-dimensional radiological approach – cone beam computed tomography (CBCT) for investigation of the facial and skeletal structures of the jaws. In our study linear parameters of the mandible and its head and of the articular fossa, and the morphology of the bone tissue structure of the articular surfaces were evaluated in three-dimensional CBCT image by defining the radiological diagnosis in 56 Angle Class II patients and in 61 Angle Class III patients with dentofacial deformations without clinically diagnosed TMJ disorders. The results of Angle Class II and Class III were compared with the results of 25 skeletally normal Angle Class I patients` group. Achieved data demonstrated that there were no explicit differences in linear parameters of mandibular head and fossa between Angle Class II and Class III dentofacial deformations` groups. Tendencies of the mandibular linear parameters as well as position and shape of the mandibular head were identified between the study groups. Statistically relevant differences between mentioned study groups were identified by the assessment of TMJ osseous tissue remodelation and degenerative structural changes; most often they occurred in Class II dentofacial deformation cases. Statistically relevant higher occurrence of the osteoarthritis was diagnosed in both Angle Class II and Angle Class III study groups. This concludes in the presumption that a load of malocclusion without pronounced clinical symptoms can create adverse changes in TMJ structures which can impact stability of orthodontic and orthognathic treatment results.