Dentistry

Abstract

Three-Dimensional Quantification of the Effects between Different Types of RME

Michael Schauseil*,Carla Waldeyer,Björn Ludwig,Berna Zorkun,Wolfgang Kater,Andreas Hellak,Heike Korbmacher-Steiner

Objectives: To analyse if Hybrid-RME has different effects on skeletal, dental and periodontal aspects when compared with those of Hyrax-RME or Hyrax-SARME.

Methods: In this retrospective multicentre-study 28 patients with a severe nasomaxillary constriction were treated either with a Hyrax-type RME (6 patients, 13.92 ± 0.36 years), with a Hybrid-RME (7 patients, 17.20 ± 2.80 years) or with a surgical assisted Hyrax-SARME (15 patients, 30.58 ± 9.26). This study was performed in analogy to the method published by Garib, et al. using the freeware OsiriX 4.0. All measurements were performed twice with an interval of two weeks and the calculated mean value of both measurements was used for statistical evaluation, which was performed using SPSS 21 for Mac.

Results: The age differences between all groups were significant (p<0.001). All appliances led to a significant skeletal and dental expansion while the buccal bone lamella reduced in dependence of the employed appliance. Effects on the suture were comparable at the canine region while they were significantly differences at the molar region, where Hyrax-RME scored first, Hybrid-RME scored second and Hyrax-SARME had the least effects. While Hyrax-RME led to the greatest, Hyrax-SARME showed the least dental expansion at premolar and molar level. Hyrax- and Hybrid-RME showed significantly enhanced skeletal effects on the maxillary base and the skeletal nose than Hyrax-SARME. Hyrax- SARME had significantly less (more than half that much) molar tilting as Hybrid-RME (0.84° vs. 1.74°/ mm activation). Hybrid-RME tended to show the least bone loss (4-12%) while Hyrax-SARME tended to show the most (20-30%).

Conclusions: In patients with a borderline-age (17-20 years) Hybrid-RME might be a promising alternative for Hyrax-RME or Hyrax-SARME to gain skeletal and dental expansion while maintaining the surrounding periodontal bones. Future studies are necessary to investigate if also a surgically assisted Hybrid-SARME might be beneficial in older patients (20+) to combine the parallel dental expansion with the pronounced skeletal effects while maintaining the surrounding bones.