الفهرس | Only 14 pages are availabe for public view |
Abstract The aim of this study was to evaluate and compare the outcomes of two protocols utilizing bone anchored maxillary protraction with an untreated control group. Thirty growing Class III subjects with maxillary deficiency in the late mixed or early permanent dentition phase were included in the study. In group 1 (n=10) skeletally anchored facemasks were employed with miniplates placed at the zygomatic buttress. In group 2 (n=10) patients were treated with Class III elastics extending from infrazygomatic miniplates in the maxilla to symphyseal miniplates in the mandible. group 3 (n=10) was an untreated control group. Pre- and post-treatment and observation period cephalometric radiographs were analyzed. Pre- and-post treatment and observation 3D digital models were analyzed, superimposed, 3D mapped and sectioned. Three dimensional stereophotogrammetry facial images were acquired before and after treatment, then superimposed and analyzed. The treatment periods were 8.0 and 8.9 months in groups 1 and 2, respectively, and the untreated control group was observed for 9.4 months. The maxilla moved forward significantly in groups 1 and 2 as compared to the untreated control group (4.87 mm in group 1 and 5.81 mm in group 2); overjet and upper incisors display were improved without proclination or mesialization of the maxillary teeth relative to the maxillary base. Soft tissue harmony demonstrated great improvement. However, group 1 showed more opening rotation of the mandible and lingual inclination of lower incisors than group 2. There were no significant changes in maxillary arch depth, maxillary intermolar width or the mandibular intermolar width in both treatment groups as well as the control group. The lower arch depth decreased significantly only in groups 1 and 3. Superimposition of the pre and post-treatment or observation maxillary 3D digital models showed no clinically significant dentoalveolar changes. The 3D soft tissue analysis showed significant treatment effects; major changes were observed in the upper lip, cheeks and middle of the face demonstrating a significant positive sagittal displacement in both treatment groups. The lower lip and chin area showed significant negative sagittal changes which indicated that the soft tissue growth in this area was restrained with backward displacement especially in group 1 more than group 2. |