Rapid maxillary expansion in adults: Can multislice computed tomography help choose between orthopedic or surgical treatment?

INTRODUCTION: The aim of this study was to evaluate the accuracy of Multislice Computed Tomography (MSCT) in the detection resistance areas on the midpalatal suture (MPS) and thus to evaluate if MSCT could be a help in the kind of maxillary expansion to be used (pure orthodontic or surgically-aided) for the correction of transverse maxillary deficiencies in adults. METHODS: Ten MSCT were obtained from 10 MPS removed from fresh corpses (mean age: 79.4; extreme: 70-86). Three standardized radiological regions of interest (ROI) were identified on each MPS and were classified into "open" (group 1) or "closed" (group 2) by 3 independent radiologists. The 30 ROI were then histologically analyzed according to 3 criteria: mean suture width (MSW), obliteration index (OI) and interdigitation index (Ii). RESULTS: Nine ROI were classified in group 1 (closed) and 21 in group 2 (open). On the histological examination, the mean MSW was 396.9mum in group 1 and 227.1mum in group 2. OI was 3.098% and 9.309% and Ii was 1.25 and 1.34 respectively. Statistically significant difference between the 2 groups was only found for the MSW. We conclude that MSCT allows for the evaluation of the width of the MPS, but not for the evaluation of the other possible parameters of resistance we used. Therefore, it cannot predict precisely the amount of resistance in the MPS and is not suited for the choice between pure orthodontic or surgically-aided expansion.