Are morphologic and topographic alterations of the mandibular fossa after fixed functional treatment detectable on tomograms? Visual classification and morphometric analysis.

Abstract

The goal was to evaluate if changes in morphology and topography of the mandibular fossa after Functional Mandibular Advancer (FMA) treatment are detectable on tomograms. Furthermore, the suitability of digital tomograms (DT) over magnetic resonance imaging (MRI) for this particular question was investigated. In all, 25patients (14female, 11male) with askeletal classII malocclusion received treatment with aFMA. DTs were available prior to (T1) and after (T2) FMA treatment. Atotal of 50 temporomandibular joints were investigated. The mandibular fossae were evaluated metrically and visually regarding treatment-induced alterations. Ap < 0.05 was set as the level for statistical significance for all tests. Results were compared to the results of arecent MRI study. Visual inspection of all 50joints in the DT at T1 and T2 revealed no alterations of the fossa shape in the sagittal plane; 24patients showed identical morphology of right and left joints. The metrical analysis revealed no significant changes regarding width, depth and ratio thereof between T1 and T2. There also were no bilateral differences. Another 18 different distance measurements between porion, mandibular fossa, articular eminence and pterygoid fossa showed no significant changes. There was no detectable proof of afossa shift. No changes in the sagittal plane, mandibular fossa, the articular tubercle, or apossible fossa shift were found in the DT of classII patients after FMA treatment. DT and MRI measurements and the visual inspection revealed identical findings; thus, DT appears to be avaluable research tool for sagittal analysis of mandibular fossa changes.