Italian researchers comparing two distalizing devices supported by palatal miniscrews—the MGBM System (MGBM) and the Distal Screw appliance (DS)—in Class II patients found that the MGBM system resulted in greater distal molar movement and less treatment time. As a result, more efficient movement was achieved with the MGBM system than that associated with the DS appliance. However, the DS system exhibited less molar tipping during distalization.
The researchers examined pretreatment (T1) and postdistalization (T2) lateral cephalograms of 53 Class II malocclusion subjects. The MGBM group included 29 patients—16 males and 13 females—with a mean pretreatment age of 12.3 ± 1.5 years. The DS appliance group included 24 patients—11 males and 13 females—with a mean pretreatment age of 11.3 ± 1.2 years. The mean distalization time was 6 ± 2 months for MGBM and 9 ± 2 months for DS. Initial and final measurements and treatment changes were compared by means of a Student t test.
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. The researchers found that distal molar tipping was greater in the MGBM group (10.3°) than in the DS group (3.0°). The first premolar showed a mean mesial movement of 1.4 mm, with a mesial tipping of 4.4°, in the MGBM. However, the first premolar showed a distal movement of 2.2 mm, with a distal tipping of 6.2°, in the DS.
The findings of the study appear in The Angle Orthodontist.
