Asymmetric rapid maxillary expansion in true unilateral crossbite malocclusion: A prospective controlled clinical study

Abstract

Objective: To investigate the short-term effects of the asymmetric rapid maxillary (ARME) appliance on the vertical, sagittal, and transverse planes in patients with true unilateral posterior crossbite. Materials and Methods: Subjects were divided into two groups. The treatment group was comprised of 21 patients with unilateral posterior crossbite (mean age 5 13.3 6 2.1 years). Members of this group were treated with the ARME appliance. The control group was comprised of 17 patients with Angle Class I who were kept under observation (mean age 5 12.3 6 0.8 years). Lateral and frontal cephalograms were taken before the expansion (T1), immediately after expansion (T2), and at postexpansion retention (T3) in the treatment group and at preobservation (T1) and postobservation (T2) in the control group. A total of 34 measurements were assessed on cephalograms. For statistical analysis, the Wilcoxon test and analysis of covariance were used. Results: The ARME appliance produced significant increases in nasal, maxillary base, upper arch, and lower arch dimensions (P , .01) and a clockwise rotation of the occlusal plane (P 5 .001). Conclusion: The ARME appliance created asymmetric increments in the transversal dimensions of the nose, maxilla, and upper arch in the short term. Asymmetric expansion therapy for subjects with unilateral maxillary deficiency may provide satisfactory outcomes in adolescents, with the exception of mandibular arch expansion. The triangular pattern of expansion caused clockwise rotation of the mandible and the occlusal plane and produced significant alterations in the vertical facial dimensions, whereas it created no displacement in maxilla in the sagittal plane. (Angle Orthod. 2015;85:245-252.)

Skeletal and dentoalveolar bilateral dimensions in unilateral palatally impacted canine using cone beam computed tomography

“…The clinical significance of our findings with respect to treatment implies a greater attention to correct the transverse asymmetries mainly at level of the first premolar on the side that includes an impacted canine. The severity of this asymmetry (approximately 2 mm between both sides) should be corrected only with dental alignment; however, in cases of greater asymmetry including unilateral cross bite, the asymmetric expansions should be taken into account [ 20 ].…”

Rapid maxillary expansion in mouth breathers: a short-term skeletal and soft-tissue effect on the nose

“…From the earliest evidence of the effects of RME on the nasal cavity 8 , 9 various studies have been undertaken focusing on skeletal changes 5 , 7 , 11 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 the first specific study on the repercussion of RME on the soft tissue of the nasal cavity was only conducted as recently as 1999. 33 Since this time, few studies have assessed the modifications to the facial soft tissue that have a tendency to stretch, accompanying the changes in the hard tissue due to bone expansion.…”

Transverse Skeletal Effects of Rapid Maxillary Expansion in Pre and Post Pubertal Subjects: A Systematic Review

“…Most of the excluded studies [11], [21], [22], [23], [24], [25], [26], [27], [28], [29], [30], [31], [32], [33], [34], [35], [36], [37], [38], [39], [40], [41], [42], [43], [44], [45], [46], [47], [48], [49], [50], [51], [52], [53], [54], [55], [56], [57], [58], [59], [60], [61], [62], [63] divided the samples into treated and untreated control groups according to their chronological age and not according to their skeletal age. Seventeen studies [11], [21], [22], [26], [27], [36], [37], [38], [45], [46], [47], [51], [52], [54], [60], [63], [64], [65] had an untreated control group with normal occlusion or with other types of malocclusions other than posterior crossbites. Other reasons for exclusion included, subjecting the control groups to treatment [11], [32], [44], case reports [66], [67], [68], [69], using interventions other than RME [50], [51], [53], [54], [56], [64], [65], [70] or absence of a control group [31], [71], [72].…”