Evaluation on expansion efficiency of microimplant-assisted rapid palatal expansion in treatment of maxillary transverse deficiency in adolescents with CBCT

Objective: To analyze and evaluate the expansion efficiency of microimplant-assisted rapid palatal expansion (MARPE) in the treatment of maxillary transverse deficiency (MTD) in the adolescents, and to provide the reference for the formulation of clinical treatment plan. Methods: The clinical materials of 20 adolescent patients with MTD, who received MARPE, were selected;the buccal maxillary width (BMW), palatal maxillary width (PMW), the amount of sutural expansion (SE), the amount of MSE appliance expansion (AE), and the first molar angle (MA) and the change values of BMW and PMW (ΔBMW and ΔPMW) before and after treatment of the patients with MTD were detected by cone beam computed tomography (CBCT) before and after treatment. The percentage of bony expansion efficiency, the percentages of alveolar bone bending amount and the percentages of remaining effects were calculated. Results: Compared with before expansion treatment, the BMW and PMW at different tooth positions were increased (P < 0.05), and the bilateral MA were decreased (P < 0.05). Compared with the ΔPMW at the first molar, the ΔBMW at the first molar was larger (t = 3.047, P < 0.05); compared with the SE at the first molar, the ΔBMW at the first molar was larger (t = 9.655, P < 0.05). Compared with the ΔBMW at the first premolar, the ΔBMW at the first molar was larger (P < 0.05). The percentages of bony expansion efficiencies from the first molar and the second premolar to the first premolar were decveased, but the percentages of alveolar bending amount and the percentages of remaining effects were increased gradually. Conclusion: MARPE can effectively open the palatal suture of the adolescents with MTD, and the efficiency of bony expansion is up to 74%. (authors)