Three-dimensional analysis of palatal shape in patients treated with SARME using traditional and geometric morphometrics.

Abstract

To demonstrate the advantages of dense surface models in the evaluation of surgical-assisted rapid maxillary expansion's effect (SARME) on palatal morphology. Furthermore, we compared the palatal surface before (T1) and after (T2) therapy with controls. Surgical-assisted rapid maxillary expansion's effect group of 15 adult patients (Le Fort I and midpalatal sagittal osteotomy, hyrax screw) and 50 adult individuals. Patients were treated in General Faculty Hospital, Prague. Eighty plaster casts were digitized using a three-dimensional laser scanner and evaluated using traditional and geometric morphometrics. An unpaired Student's t-test on the controls and the SARME T1 group revealed significant differences in all width measurements. Between the controls and the SARME T2 group, significant differences were only related to the interdental angle between the first molars and particularly to the palatal height. The most remarkable differences between the pre- and post-treatment palatal morphology were a widening of the dental arch and buccal shift of the lateral teeth associated with apparent flattening of the alveolar crest. Dense surface model provided descriptive visualization of the treatment effect and was helpful in the evaluation of palatal shape variability including detection of the most difficult patients. Correction of the dental arch width discrepancy by SARME was successfully achieved. After therapy, palatal shape variability of most of the patients was comparable to the variability of the control group.