ABSTRACT
The purpose of this study was to compare the effects of 2 mandibular anchorage systems used with a 3-dimensional bimetric maxillary distalizing arch. The Wilson rapid molar distalization appliance for Class II molar correction was used with 26 patients; two groups of 13 patients each were formed. In the first group (9 girls, 4 boys with a mean age 11 years 5 months), mandibular anchorage was gained by a modified lip bumper with a standard lingual arch of 0.9-mm stainless steel. The second group (7 girls, 6 boys, with a mean age of 13 years) had a 0.016 x 0.016-inch utility arch, with a 3-dimensional lingual arch for anchorage. Cephalometric radiographs were taken before and after maxillary first molar distalization. The treatment results showed that the extrusion of the mandibular first molar was statistically significant in both the modified lip bumper and utility arch groups (P < .01 and P <.05, respectively). The incisal edge of the mandibular incisor moved forward significantly in the modified lip bumper and utility arch groups (P < .05 and P < .01, respectively); however, the protrusion in the utility arch group was significantly greater than in the lip bumper group (P <.05). In both groups, significant proclination of the mandibular incisor was observed (P < .01). Comparison of the anchor units showed that there was significantly greater proclination in the utility arch group than in the modified lip bumper group (P < .05). Both anchor units similarly enhanced the mandibular first molar anchorage. However, particularly in the utility group, mandibular incisor anchorage control seemed to be inadequate.
Subject(s)
Mandible/pathology , Maxilla/pathology , Orthodontic Anchorage Procedures/instrumentation , Orthodontic Appliance Design , Orthodontic Appliances/classification , Tooth Movement Techniques/instrumentation , Cephalometry , Child , Female , Humans , Incisor/pathology , Lip , Male , Malocclusion, Angle Class II/pathology , Malocclusion, Angle Class II/therapy , Molar/pathology , Orthodontic Wires , Stainless Steel , Surface Properties , Tooth Movement Techniques/methodsABSTRACT
The aim of this study was to compare the effects of the double-plate appliance (DPA) and the facemask (FM) in treating skeletal Class III malocclusions. Data were based on the pretreatment and posttreatment lateral cephalograms of 28 subjects with skeletal and dental Class III malocclusions. In the first group (7 girls, 7 boys; mean age, 10 years 3 months), each subject wore a DPA with 2 Class III elastics, which exerted a force of 350-400 g day and night except for meals. In the second group (7 girls, 7 boys; mean age, 10 years 5 months), each subject wore a Delaire-type FM with a removable intraoral appliance with a total force of 600 g. The patients were instructed to wear the appliance approximately 16 hours a day. An untreated control group (6 girls, 8 boys; mean age, 9 years 8 months) was formed that matched the treatment groups according to sagittal skeletal and dental classifications. Thirteen angular and 14 linear measurements were evaluated. The increase in ANB angle and the decrease in maxillomandibular differential in the treated groups showed significant differences compared with the control group (P < .05). The increases in ANB and SNA angles in the FM group were significantly greater than in the DPA group (P < .05). The increases in lower facial height and Me-ANS in the FM group were significantly different compared with the other groups (P < .05). The overjet increased significantly in both treatment groups (P < .001), but, in the DPA group, overjet was significantly greater than in the FM group (P < .05). Protrusion of the maxillary incisors and retrusion of the mandibular incisors in the DPA group showed significant differences compared with the other groups (P < .05).
