Evaluation of the changes in the upper central incisors after rapid maxillary expansion

Objective: Short-term evaluation of the changes in the position of permanent upper central incisors after rapid maxillary expansion. Method: This researchstudy comprised 33 mouth-breather patients with maxillary atresia, 9.51year-old average age, 2.32 standard deviation and age ranging from 6.5 to 14.7years of age. Patients underwent computed tomography in twostages: (T1) before rapid maxillary expansion and (T2) three months after rapidmaxillary expansion. Five linear variables (1-NA, 1-N, 1-Cli, 1-ENP, (ENA-N)-1) and five angular variables (SN.1, N-S.Cli-1, SN.(axis)1, N.ENA.ENP, Rhi-1.ENA-ENP) were analyzed, all of them coming out from the incisal edge of thebuccal inclined upper central incisor. With the data collected through the OsirixMD imaging program, the evaluations of individual changes, before and afterrapid maxillary expansion procedures, were performed accordingly. Results: Significant increase was found in the 1-N (+0.96mm, +1.3%, p=0.003) and inthe 1-Clinoid (+1.26mm, +1.3%, p<0.001) linear variables and a decrease wasfound in the SN.1 (-1.61mm, -1.5%, p=0.034) angular variable. The remainingvariables have not shown significant variables between stages T1 and T2. Conclusion: It can be concluded that there is significant protrusion and lingualinclination of the permanent upper central incisor teeth after rapid maxillaryexpansion in a short-term evaluation analysis.