Avaliação da posição e forma do disco das articulações temporomandibulares por meio da ressonância magnética em crianças e pré adolescentes tratados com expansão rápida da maxila e protração maxilar

Abstract

Objective:The aim of this prospective clinical study was to evaluate, using magnetic resonance imaging, possible changes in the position and shape of the temporomandibular joint disc in children and pre-adolescents treated with two different rapid maxillary expansion and facemask protocols. Methods: The convenience sample consisted of 88 patients, of both genders, Class III or Class III Subdivision malocclusion, aged between 6 and 13 years, selected at the Department of Orthodontics of University Santa Cecília and divided into 3 groups.Group 1 consisted of 34 patients, 8 boys and 26 girls treated with rapid maxillary expansion, followed by face mask therapy (11.41±3.13 months). Group 2 consisted of 34 patients, 18 boys and 16 girls, treated with rapid maxillary expansion according to the modified alternative protocol of rapid maxillary expansion and constriction followed by face mask therapy (13.26±2.77 months). These treated groups were randomly distributed with a 1:1 allocation ratio according to the two treatment protocols. The other 20 untreated patients from group 3 - Control Group, 9 boys and 11 girls, with a mean age of 7.83 ± 1.39 years were followed up (11.35 ± 2.98 months). Temporomandibular joints were obtained by magnetic resonance imaging before (M1) and after (M2) a period of treatment or follow-up. McNemar's test, Fisher's exact test and intra- and interobserver agreement (K) (p ≤ 0.05) were performed.Results: There was no statistically significant difference in baseline cephalometric variables at M1 between the groups. There was a statistically significant difference between the groups (p< 0.001) in relation to the shape of the disc in M1, with G1 showing a greater occurrence of altered shapes compared to G2. No significant differences were observed in the position and shape of the disc, between M1xM2, for any of the groups studied.Conclusion:It can be concluded that during the study period, the treatment protocols employed did not result in significant changes in the position and shape of the temporomandibular joint disc assessed by MRI in children and pre-adolescents with Class III or Class III Subdivision malocclusion.Registry: Brazilian registry of clinical trials (RBR-4ysjz3b).