Three-dimensional evaluation of maxillary tooth movement in extraction patients with three different miniscrew anchorage systems: a randomized controlled trial

Abstract

Objective To compare the three-dimensional (3-D) movement of maxillary teeth in response to three common miniscrew anchorage systems in extraction patients with maxillary dentoalveolar protrusion. Materials and methods The study employed a randomized controlled single-blinded design with three arms. Thirty extraction patients who required maximum anchorage to retract maxillary anterior teeth were included and randomly allocated into three treatment groups: space closure with direct miniscrew anchorage and low crimpable hooks (DL group), indirect miniscrew anchorage and low crimpable hooks (IL group), and direct miniscrew anchorage and high crimpable hooks (DH group). Cone beam computed tomography (CBCT) images of all included patients were obtained immediately before (T0) and after (T1) space closure. The outcomes were 3-D positional changes of maxillary central incisor, lateral incisor, canine, second premolar, and first molar. The repeated measures analysis of variance with post hoc LSD test was used to evaluate differences among groups. Results A significant intrusion (− 1.34 mm; 95% CI, − 1.60 mm, 1.08 mm) and buccal (− 6.92°; 95% CI, − 8.67°, − 5.13°) and distal (4.90°; 95% CI, 3.75°, 6.04°) inclination of the maxillary first molars were observed in the DL group, compared to the other two groups. The mesial movement (− 0.40 mm; 95% CI, − 0.83 mm, − 0.03 mm) of the maxillary first molars was found in the IL group, while the DL (0.44 mm; 95% CI, 0.15 mm, 0.73 mm) and IL (0.62 mm; 95% CI, 0.28 mm, 0.96 mm) groups exhibited distal movement. In the DH group, the lingual inclination changes of maxillary central incisor (5.04°; 95% CI, 2.82°, 7.26°) were significantly lower, which is indicative of good lingual root torque control of the maxillary anterior teeth. Conclusion Three miniscrew anchorage systems produced significantly different 3-D maxillary tooth movement. The maxillary first molars were significantly buccally and distally inclined and intruded in patients using direct miniscrew anchorages with low crimpable hooks. Direct miniscrew anchorages with high crimpable hooks could help to achieve better lingual root torque control of the maxillary incisors. Trial registration The trial was registered at www.chictr.org.cn (ChiCTR1900026960). Registered 27 October 2019.

Biomechanical analysis of total arch maxillary distalization using infrazygomatic crest miniscrews: a finite element analysis study

“…Absolute anchorage with MS has been widely used [ 1 , 3 , 5 , 6 , 12 ] as it provides a biomechanically solid anchorage for teeth movement, thus preventing unnecessary teeth displacement and decreasing overall treatment time when compared to intra-arch distalization when the posterior segment is moved first and then the anterior segment [ 2 , 3 , 5 , 26 ]. En-masse distalization of posterior teeth with IZC MS can be done without changing the screw position [ 1 , 3 , 12 ]. This study used IZC MS heads placed 11 mm above the mesiobuccal cusp of the maxillary second molar, which is a clinically favorable location for screw placement.…”

“…They have focused on the potential for molar distalization, the amount and direction of the incisor’s tipping, occlusal plane changes, facial profile effects, and transverse changes resulting from this mechanics’ type [ 9 – 11 ]. The height of the anterior support hook and the distance from the MS head to the occlusal plane are crucial to designing a force system that meets occlusal and esthetic goals [ 12 ].…”

Long-term bone remodeling of maxillary anterior teeth with post-treatment alveolar bone defect in adult patients with maxillary protrusion: a prospective follow-up study

“…All CBCT images were standardized and oriented as follows: the horizontal plane was defined as the Frankfort horizontal plane (Or-Po); the mid-sagittal plane was defined as the plane connecting the nasion, anterior nasal spine, and posterior nasal spine (Na-ANS-PNS). The maxillary region was selected for voxel-based superimposition as described previously [ 18 ]. The CBCT images at T1 and T2 were superimposed to analyze the teeth movement and alveolar bone change before and after orthodontic treatment, and CBCT images at T2 and T3 were superimposed to analyze the teeth movement and alveolar bone change during the retention period.…”

“…To analyze the maxillary anterior teeth movement, a 3D coordinate system in the superimposition model was established, as described previously [ 18 ]. The Na-ANS-PNS plane (sagittal plane), Frankfort horizontal plane (axial plane), and the plane perpendicular to these two planes (coronal plane), were selected as the X, Y, and Z planes, respectively.…”