Comparison between direct vs indirect anchorage in two miniscrew-supported distalizing devices

Abstract

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.)

Maxillary molar distalization with miniscrew-supported appliances in Class II malocclusion: A systematic review

“…Miniscrew-supported appliances have experienced widespread clinical use and various studies have demonstrated their skeletal and dentoalveolar effects. 6,7,10,[15][16][17][18][19][20][21][22][23][24][25][26][27] The present systematic review was conducted to examine the effectiveness of miniscrewsupported appliances for maxillary molar distalization in Class II malocclusion. 21 Prospective 2 MS/Subject (24) Miniscrews placed in the interradicular space Polat-Ozsoy et al, 2008 20 Retrospective BAPA/HP one or 2 MS/subject (31) BAPA/HP Escobar et al, 2007 19 Prospective BSP, 2 MS/subject (30) BSP Gelgor et al, 2007 25 Prospective MSV/MSP one per subject (40) VFV/PFV Kircelli et al, 2006 17 Prospective BAPA, 1 MS/Subject (10) BAPA Gelgor et al, 2004 24 Prospective /One per subject (25) Intramaxillary fixation screw a MS indicates miniscrew; SD, self drilling; ST, self tapping; SDJ, skeletonized distal jet; MD, molar distalization; PMD, premolar distalization; AL, anchorage loss; MISDS, miniscrew implant-supported distalization system with two miniscrews per subject; BAPA, bone-anchored pendulum appliance; MGBM, MGBM system with interradicular miniscrew; DS, distal screw appliance with palatine miniscrew; DJ, distal jet appliance; HP, Hilgers Pendulum; MSV, miniscrew with vestibular force; MSP, miniscrew with palatal force; VFV, vestibular force vector appliance; PFV, palatinal force vector appliance; BSP, bone-supported pendulum.…”

“…Distal tipping of the molar was minimal when the distalizing force was applied palatally as the reactive forces were located gingivally, close to the center of resistance of the molar. 24,25 Cozzani et al compared the distal screw appliance with the MGBM system 7 and distal jet appliance. 6 The results showed that distal tipping of the molars was minimal with the distal screw with more bodily movement of the molars.…”

“…In comparison to mini implants, miniscrews are less expensive and less invasive. 6,7 Miniscrew anchorage not only causes distal movement of premolars, but also prevents flaring of maxillary incisors, an undesirable side effect of molar distal movement, but could also cause significant distal movement of the incisors. In the present systematic review, eight out of 14 studies showed distalization of premolars and incisors and the mean distal movement of premolars and incisors varied from 1.75 mm to 5.4 mm and 0.1 mm to 2.7 mm, respectively.…”

“…The main disadvantages with extraoral anchorage is the need for patient compliance and it is esthetically unacceptable. 1,2 To overcome these limitations, many intraoral methods were used to distalize molars such as the use of magnets, 4 pendulum appliance, 5 distal jet appliance, 6,7 nickel-titanium open coil springs 3,4 and several other methods. The common and unwanted side effect of these intraoral methods is the mesial shift of premolars and incisors leading to anchorage loss.…”

“…10 In searching the literature, there were a few systematic reviews 12,13 and a meta-analysis 14 conducted on the success rate and anchorage quality of miniscrew implants. Except for several studies that showed the effectiveness of the miniscrew-supported appliance in molar distalization, 6,7,[15][16][17][18][19][20][21][22][23][24][25][26][27] there was no systematic review synthesizing the evidence for the use of a miniscrew in molar distalization. To address this, a systematic review of the literature was conducted to evaluate the quantitative effects of the miniscrewsupported appliance in maxillary molar distalization in Class II malocclusion.…”