Magnetic resonance imaging in the assessment of the temporomandibular joint structure following mandibular advancement / 中华口腔医学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the changes in the disc-condyle-fossa relationship following mandibular advancement.</p><p><b>METHODS</b>Twenty-five patients (10 boys and 15 girls, 11.1 +/- 1.1 years) with class II division 1 malocclusions were treated with Activator. The average treatment time was 10.9 months. Parasagittal MRIs in closed mouth position were analyzed before and after Activator treatment by means of the pair-t test.</p><p><b>RESULTS</b>Ca-Tm value [(-0.1 +/- 1.5) mm and (-0.6 +/- 0.9) mm] of the left temporomandibular joint (TMJ) and Ca-Ca' value [(2.3 +/- 0.8) mm and (1.8 +/- 0.5) mm] of the right TMJ were changed significantly after Activator treatment (P < 0.05). This indicated that the condyle was located anteriorly in the fossa. No significant changes were found in the disc-fossa relationship and disc-condyle relationship (P > 0.05).</p><p><b>CONCLUSIONS</b>Activator could promote the growth of the mandible and at the same time, it had no apparent negative influence on TMJ function.</p>