Treatment Effects of Distal Movement of Lower Arch With Miniscrews in the Retromolar Area Compared With Miniscrews in the Posterior Area of the Maxillary

Abstract

The aim of this study was to compare the effects of group distal movement of lower teeth obtained with the aid of direct usage of miniscrews in the retromolar area and indirect usage of miniscrews in the posterior area of the maxillary. Nineteen patients with mild-to-moderate class III malocclusion (4 males and 15 females) were divided into 2 groups. Ten patients (2 males and 8 females; mean age, 20.7 ± 2.5 years) in group 1 were treated by miniscrews in the retromolar area. Nine patients (2 males and 7 females; mean age, 21.5 ± 3.7 years) in group 2 were treated by miniscrews in the posterior area of the maxillary. Lateral cephalometric headfilms were taken at the beginning of treatment and after distal movement of mandibular dentition for the evaluation of the treatment changes. In group 1, the crown and root apex of lower first molars were moved distally by 3.4 mm and 1.2 mm with distal tipping of 8.7 degrees and intruded by 0.7 mm. In group 2, the crown and root apex of lower first molars were moved distally by 3.3 mm (P = 0.8976, P > 0.05) and 0.2 mm (P = 0.0124, P < 0.05) with distal tipping of 10.7 degrees (P = 0.0467, P < 0.05) and extruded by 0.2 mm (P = 0.0124, P < 0.05). Retraction of the mandibular arch lasted 6.31 ± 1.45 months for group 1 and 7.61 ± 1.46 months for group 2. Direct usage of miniscrews in the retromolar area took less time and more bodily movement to retract the lower arch without cooperation of the patients and was a better choice for the patients with potential temporomandibular joint disorders problems.