Estudo, em exames de tomografia computadorizada, da simetria das estruturas da articulação temporomandibular e relação côndilo-fossa nas más oclusões Classe I, Classe II e Classe III

Abstract

Thirty persons ranging from 13 years to 30 years of age with Class I malocclusion, thirty persons ranging from 12 years to 38 of age with Class II Division 1 malocclusion and sixteen persons ranging from 13 years to 41 years of age with Class III malocclusion underwent computed tomography of the temporomandibular joints. The images obtained from axial slices were evaluated for possible asymmetries in size and position that may exist between the condylar processes associated with these malocclusions. The images obtained from sagittal slices were used to assess the depth of the mandibular fossa, the condyle-fossa relationship, and the concentric position of the condyles associated with these alocclusions. Paired Student t tests were applied, and Pearson product moment correlations were determined after measurements on both right and left sides were obtained. The results of this study showed no statistically significant asymmetries between the condylar processes evaluated in Class I sample. No statistically significant asymmetries were found in the depth of the mandibular fossa, in the anterior joint space and superior joint space. The posterior joint space showed statistically significant asymmetry (P < .05) between right and left sides. In Class II Division 1 malocclusion sample the distance condylar process/ midsagittal plane (P: .019) and posterior joint space (P: .049) showed statistically significant asymmetry between right and left sides. In Class III malocclusion sample no statistically significant asymmetries were found between right and left sides. A statistically significant (P < .05) anterior positioning of the condyles was observed (nonconcentric positioning) in Class I, Class II Division 1 and Class III group. In the Class I malocclusion sample, of all measurements evaluated, only the posterior articular space showed statistically significant difference between the right side and the left side. There was a higher mean for the posterior articular space on the right TMJ. In the Class II Division 1 malocclusion sample, the distance condylar process/ midsagittal plane and the posterior articular space showed statistically significant difference between the right and left sides. In the Class III sample there was no statistically significant difference between the right and left sides. Evaluation of the concentric position of the condyles in their respective mandibular fossae showed a nonconcentric positioning for right and left sides in the Class I, in the Class II and in the Class III malocclusion groups.