Tooth-Bone-Borne vs Bone-Borne Rapid Maxillary Expanders on Dentoskeletal Changes.

Purpose: This study compared the insertion and thickness of the cortical bone, the parallelism of the midpalatal suture, and the skeletal transverse dimension using a microimplant-assisted rapid palatal expansion (MARPE) with those produced by bone-anchored maxillary expander (BAME) in adults. Patients and Methods: The sample comprised 18 patients (mean age, 29.9±9.4 years) selected for the MARPE group and 18 (mean age 24.8±6.8 years) selected for the BAME group. Cone-Beam computed tomography scans taken just before and after the expansion. Results: After treatment, there was a significant palatal depth decrease. In addition, maxillary and mandibular width were increased in both groups. Regarding the cortical bone insertion and cortical bone width, it is shown an increase in both groups but those changes are not significant. However, the anterior suture opening effect occurs more frequently in the BAME than in the MARPE device. There are no differences in the frequency of opening of the midpalatal suture in the cases treated with MARPE and BAME, in both cases the most frequent opening morphology is parallel, independently of midpalatal suture maturation. Conclusion: There are no differences in the use of MARPE or BAME in the parallelism of the middle palatal suture, the cortical bone insertion, and thickness according to the maturation stages of the midpalatal suture but significantly increases the transverse dimensions of the maxillary skeleton.

Short-term outcomes in the upper airway with tooth-bone-borne vs bone-borne rapid maxillary expanders.

BACKGROUND: This study compared the area and minimal section of the nasal cavity, nasopharynx, oropharynx, and hypopharynx in cases treated with different methods of microimplant-assisted expansion. METHODS: Based on a pilot study to calculate the sample size, 30 patients with transverse maxillary deficiency over 14 years of age were retrospectively selected. These patients had received two different types of microimplant-assisted maxillary expansion treatment (MARPE and BAME). The patient underwent Cone-Beam computed tomography (CBCT) before and after treatment (mean time 1.5 months) with MARPE or BAME and upper airway measurements (volume and minimum cross-sectional area) were taken to assess upper airways changes and compare changes between the groups. A paired sample t-test was performed to evaluate the T0-T1 change of airway measurements obtained with MARPE and BAME, and a student t-test to compare changes in airway measurements between MARPE and BAME. RESULTS: This investigation shows a statistically significant increase in total nasopharyngeal airway volume (0.59 ± 1.42 cm3; p < 0.01), total oropharyngeal airway volume (3.83 ± 7.53 cm3; p < 0.01) and minimum oropharyngeal cross-section (53.23 ± 126.46 mm2; p < 0.05) in all cases treated with micro-screw assisted expansion. The minimal cross-sectional area of the oropharynx ((79.12 ± 142.28 mm2; p < 0.05) and hypopharynx (59.87 ± 89.79 mm2; p < 0.05) showed significant changes for cases treated with BAME. As for the comparison between cases treated with MARPE and BAME, no differences in upper airway changes have been observed, except for the minimum cross-sectional area of the nasal cavity, which increases for MARPE (52.05 ± 132.91 mm2) and decreases for BAME (-34.10 ± 90.85 mm2). CONCLUSIONS: A significant increase in total area and minimal section at the level of nasopharynx and oropharynx was observed in cases treated with BAME. Regarding the comparison of MARPE and BAME treatments, no differences were found in the total airway volume and minimal section in upper airway except for the minimum cross section of the nasal cavity that increases for MARPE and decreases for BAME.

Changes in Molar Tipping and Surrounding Alveolar Bone with Different Designs of Skeletal Maxillary Expanders.

This study compared the buccolingual angulation (BLA) of the upper and lower first permanent molars before and after using the different methods of microimplant-assisted expansion in adults and its influence on bone insertion loss. METHODS: Cone-beam computed tomography scans taken before and after the expansion in 36 patients (29.9 ± 9.4 years) were used to assess dental and periodontal changes and compare changes between the groups. RESULTS: This research shows a statistically significant increase in the BLA of the upper first molars. An increase of the BLA of the lower molars is also observed in MARPE. Regarding the comparison between cases treated with MARPE (4.42° ± 10.25°; 3.67° ± 9.56°) and BAME (-0.51° ± 4.61°; 2.34° ± 4.51°), it was observed that upper molar torque increased significantly less in cases treated with BAME. In cases with CWRU < 96° at T0, a slight bone insertion gain was observed at T1, whereas if CWRU ≥ 96°, a slight bone insertion loss was observed. Regarding the labial cortical bone loss, a slight gain of CBW was observed in all cases. This labial cortical enlargement (T0-T1) is greater in cases where the CWRU < 96° at T0. CONCLUSIONS: Patients treated with MARPE show torque increase in the teeth selected to support the expansion appliance compared to cases treated with BAME. In cases where the BLA at T0 < 96°, an increase in thickness and cortical insertion is observed in the upper molars after treatment with disjunction appliances assisted with microscrews.