Objective: To compare two distalizing devices supported by palatal miniscrews, the MGBM System (MGBM) and the Distal Screw appliance (DS), in dental Class II patients. Materials and Methods: Pretreatment (T1) and postdistalization (T2) lateral cephalograms of 53 Class II malocclusion subjects were examined. MGBM consisted of 29 patients (16 males, 13 females) with a mean pretreatment age of 12.3 6 1.5 years; DS consisted of 24 patients (11 males, 13 females) with a mean pretreatment age of 11.3 6 1.2 years. The mean distalization time was 6 6 2 months for MGBM and 9 6 2 months for DS. Initial and final measurements and treatment changes were compared by means of a Student's t-test. Results: Maxillary superimpositions showed that the maxillary first molar distalized an average of 5.5 mm in the MGBM and 3.2 mm in the DS between T1 and T2; distal molar tipping was greater in the MGBM (10.3u) than in the DS (3.0u). First premolar showed a mean mesial movement of 1.4 mm, with a mesial tipping of 4.4u in the MGBM; on the contrary, first premolar showed a distal movement of 2.2 mm, with a distal tipping of 6.2u, in the DS. Conclusions: The MGBM system resulted in greater distal molar movement and less treatment time, resulting in more efficient movement than was associated with the DS; DS showed less molar tipping during distalization. (Angle Orthod. 2016;86:399-406.)
BackgroundThe purpose of this retrospective study is to investigate the dentoalveolar and skeletal effects of two distalizing protocols featuring different anchorage systems used in patients with class II malocclusion: the MGBM system (skeletal anchorage) and Pendulum (intraoral anchorage).MethodsThe sample comprised 57 patients who were assigned to one of the two treatments: the MGBM group (30 patients, mean age 13.3 ± 2.3 years) or the Pendulum group (27 patients, mean age 12.8 ± 1.7 years). Three serial cephalograms were obtained at baseline (T0), after molar distalization (T1), and after fixed appliance treatment (T2). Esthetic, skeletal, and dental parameters were considered. Pancherz's superimposition method was used to assess sagittal dental changes. The initial and final measurements and treatment changes were compared by means of a paired t test or a paired Wilcoxon test. Statistical significance was tested at p < 0.05, p < 0.01, and p < 0.001.ResultsIn the MGBM group, the upper molar distalization was achieved in 7 months and showed a mean value of 4.9 mm (ms-PLO); the amount of molar relationship correction was 5.9 mm. In the Pendulum group, the upper molar distalization was obtained in 9 months and showed a mean value of 2.5 mm (ms-PLO), while the molar relationship correction amounted to 4.9 mm. Anterior anchorage loss occurred in both groups, although in the MGBM group, there was less mesial movement of the premolars.ConclusionsThe MGBM system and the Pendulum appliance are both effective in the correction of class II malocclusions. The MGBM system was found to be more efficient than the Pendulum appliance, producing greater molar distalization in a shorter treatment time.
This case report describes orthodontic treatment including both skeletal maxillary expansion and unilateral distalization by means of a single bone-borne appliance followed by clear aligner therapy in a young adult patient. A surgical guide was digitally designed and three-dimensionally printed to facilitate the placement of four miniscrews in the palatal vault. The miniscrews were fitted and the bone-borne appliance was delivered in a single clinical appointment. The postexpansion photographic records and models demonstrate the opening of the palatal median suture, the pure skeletal expansion, and the resolution of the left crossbite after 40 activations. Specifically, left molar Class I was obtained in about 5 months without any loss of anterior anchorage, and the subsequent aligner phase achieved all of the objectives established in the treatment plan. This case report shows clearly how careful digital planning of miniscrew insertion and the delivery of a pure bone-borne appliance in a single sitting enabled good clinical outcomes to be achieved in an acceptable timeframe, without side effects, even in a young adult patient.
Background
Regardless of the treatment protocol, stability in Class III patients always represents a major concern. The aim of this study was to assess the short and long-term skeletal and dentoalveolar modifications in a group of class III patients treated with hybrid rapid maxillary expander (RME) and facemask (FM). Indeed, no long-term studies have been conducted yet with the objective of evaluating the effects of this kind of approach when applied to patients who have already gone thought their peak of growth.
Material and methods
27 patients with skeletal Class III malocclusion were treated using hybrid RME according to alternating rapid maxillary expansion and constriction (ALT-RAMEC) protocol, followed by 4 months of facemask therapy. After the orthopaedic phase, each patient underwent orthodontic treatment with fixed multibracket appliances. A mean follow-up of 7 years, 10 months was performed. Pre-treatment (TO), post-treatment (T1) and follow up (T2) cephalometric tracing were analysed, comparing dental and skeletal measurements.
Results
Point A advanced by a mean of 3.5 mm with respect to VerT, then relapsed by 0.7 in the post-facemask period, thereby yielding of a mean advancement of 2.7 at T2. The sagittal relationship significantly changed after RME + facemask protraction (3.8° of ANB and 5.189 mm of Wits). Although both Wits and ANB values worsened over time, the improvement from T0 is still appreciable at T2.
Conclusion
Despite the physiological relapse due to mandibular growth, the long-term cephalometric follow-up confirms the maintenance of all positive outcomes of the previous orthopaedic treatment with hybrid RME and facemask.
Introduction: Problem solving in Class II malocclusion treatment performed with premolars extractions or distalizing techniques in relation to the profile modification.
Aim: To cephalometrically compare soft tissue changes produced either by maxillary premolar extraction, tooth-borne Pendulum appliance or bone-borne MGBM appliance.
Materials and Methods: Both pre- (T1) and post-treatment (T2) lateral cephalograms of 89 skeletal Class II patients (36 M, 53 F), treated during pubertal growth spurt, were retrospectively selected. Three groups were formed based on the therapy performed: 30 patients had been treated with maxillary first premolars extraction (U4), 31 patients with a conventional tooth-borne distalizing with Pendulum appliance (PA), and 28 patients with a skeletally anchored distalizing appliance (MGBM). Soft tissue was analyzed comparing upper (UL) and lower (LL) lip’s points with regard to True Vertical Line (TVL) and Esthetic plane (E-plane). Skeletal and dental values have been recorded in order to cephalometrically compare ΔT2-T1 changes among groups and to correlate dental and skeletal changes to profile modifications. One-way ANOVA was employed to compare groups at T1. Paired sample t-tests were employed to assess significant intra- and intergroup differences between T2 and T1. Significance level was set at 0.05
Results: UL and LL showed a slight but not significant retrusion relative to TVL in all three groups. UL and LL distances to E-plane were not statistically significant among U4, PA, and MGBM groups. Independently of the treatment, UL was tangent to TVL in all groups. No statistically significant differences have been shown in skeletal records. Significant differences were recorded in Overjet among U4 than PA and MGBM groups.
Conclusions: Class II malocclusion treatment with maxillary first premolar extraction, conventional or skeletal distalization did not significantly affect the profile producing similar changes in the soft tissue.
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