Effectiveness of maxillary protraction using a hybrid hyrax-facemask combination: A controlled clinical study

Abstract

Objective: To evaluate the treatment effects of a hybrid hyrax-facemask (FM) combination in growing Class III patients. Material and Methods: A sample of 16 prepubertal patients (mean age, 9.5 6 1.6 years) was investigated by means of pre-and posttreatment cephalograms. The treatment comprised rapid palatal expansion with a hybrid hyrax, a bone-and toothborne device. Simultaneously, maxillary protraction using an FM was performed. Mean treatment duration was 5.8 6 1.6 months. The treatment group was compared with a matched control group of 16 untreated Class III subjects. Statistical comparisons were performed with the Mann-Whitney U-test. Results: Significant improvement in skeletal sagittal values could be observed in the treatment group over controls: SNA: 2.4u, SNB: 21.7u, Co-Gn: 22.3 mm, Wits appraisal: 4.5 mm. Regarding vertical changes, maintenance of vertical growth was obtained as shown by a small nonsignificant increase of FMA and a small significant decrease of the Co-Go-Me angle. Conclusions: The hybrid hyrax-FM combination was found to be effective for orthopedic treatment in growing Class III patients in the short term. Favorable skeletal changes were observed both in the maxilla and in the mandible. No dentoalveolar compensations were found. (Angle Orthod. 2015;85:764-770.)

Differential treatment effects of two anchorage systems for rapid maxillary expansion: a retrospective cephalometric study

“…Several clinical studies and case reports with different treatment protocols have combined this hybrid hyrax with facemasks for maxillary protraction in Class III patients [48,[54][55][56]69]. Some of these studies [54][55][56] demonstrated advancement of the maxillary complex by statistically significant amounts which, due to the extraoral forces from facemasks, were larger than reported in the present study.…”

Effectiveness of interceptive treatment of class III malocclusions with skeletal anchorage: A systematic review and meta-analysis

“…In 2 of the studies the skeletal anchorage device consisted of microscrews [20–23], while the remaining 7 used miniplates [14,19,21,22,24–26]. As regards the location of the miniplates and miniscrews in the craniofacial structures, Şar et al [19] placed miniplates at the level of the maxillary part of the lateral nasal wall and in the symphysis mentalis.…”

“…Cha & Ngan [24] placed them at the level of the zygomatic process, while other authors [14,21,22,25] situated them in this area and in the mandible between the lateral incisors and the lower canines. For their part, Niemkemper et al [20] positioned miniscrews on both sides of the mid-palatal suture and Ge et al [23] set them in the zygomatic arch. Lastly, Koh & Chung [26] did not specify the position of the miniplates on the maxilla.…”

“…The other 7 studies [14,19,20,23–26] employed similar parameters. To examine the antero-posterior relationship of the maxillae, all these authors used ANB and Wits appraisal and some also used SNA and SNB [20,23,24,26]. Additionally, 4 of the 7 articles also recorded overjet and overbite [14,20,23,25].…”

“…According to the studies included in this review, candidates for treatment with skeletal anchorage devices will present skeletal Class III malocclusions in a growing patient with maxillary deficiency, dental Class III malocclusion, Wits ≤-1, anterior crossbite or edge-to-edge occlusion and stage CS1-CS3 cervical vertebra maturation [14,20–23,25]. …”