A retrospective comparison of two protocols for correction of skeletal Class III malocclusion in prepubertal children: hybrid hyrax expander with mandibular miniplates and rapid maxillary expansion with face mask.

Jan 23, 2023

Experts: Nour Eldin Tarraf,Oyku Dalci,Kerem Dalci,Ayse Tuba Altug,M Ali Darendeliler

This study compared the skeletal and dental effects of a hybrid maxillary expander with mandibular miniplates (HE-MP) and Class III elastics to conventional tooth-borne rapid maxillary expander and face mask (RME-FM) in skeletal Class III treatment.
This retrospective study included 36 skeletal Class III patients. Eighteen patients (mean age 10.24 ± 1.31 years) were treated with a hybrid expander, two mandibular L-shaped miniplates and full-time Class III elastics (HE-MP group). Their results were compared to a group of patients treated with conventional RME-FM (n = 18; mean age 10.56 ± 1.41 year). Radiographs were taken before (T1) and after treatment (T2). All patients were in cervical maturation stages CS1-CS3 at T1. The measured outcomes were the changes in sagittal and vertical skeletal and dental cephalometric measurements.
Treatment time was approximately 15.5 ± 2.8 months with the HE-MP and 11.85 ± 3.41 months for the RME-FM. The Class III malocclusion was corrected in both groups with significant changes. The maxilla advanced more in the HE-MP group, with an increase in SNA of 4.26° ± 2.15° compared to 1.14 ± 0.93 in the RME-FM group (p < 0.001). The effect on the mandible was similar in both groups, while the overall skeletal change was significantly greater with HE-MP, with an increase in the ANB of 5.25° ± 2.03° and a Wits appraisal increase of 6.03 ± 3.13 mm, as opposed to 2.04° ± 1.07° and 2.94 ± 1.75 mm with the RME-FM (p < 0.001). Dental changes were significantly higher with RME-FM, with an increase in incisor inclination (U1-SN) of 5.02° ± 3.93° (p < 0.001), with no significant changes in the HE-MP group. The mandibular incisors retroclined by 5.29° ± 3.57° at L1-MP with the RME-FM, while they advanced slightly with the HE-MP by 2.87° ± 5.37° (p < 0.001).
The use of skeletal anchorage for maxillary expansion and protraction significantly increases skeletal effects and reduces dental side effects compared to tooth-borne maxillary expansion and protraction. These results need to be investigated in the long term.

© 2022. The Author(s).

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ABOUT THE EXPERTS

Nour Eldin Tarraf,Oyku Dalci,Kerem Dalci,Ayse Tuba Altug,M Ali Darendeliler

Nour Eldin Tarraf

Discipline of Orthodontics and Paediatric Dentistry, Sydney Dental School, Faculty of Medicine and Health, University of Sydney, Sydney, Australia. noureldintarraf@hotmail.com.

Oyku Dalci

Discipline of Orthodontics and Paediatric Dentistry, Sydney Dental School, Faculty of Medicine and Health, University of Sydney, Sydney, Australia.

Kerem Dalci

Discipline of Orthodontics and Paediatric Dentistry, Sydney Dental School, Faculty of Medicine and Health, University of Sydney, Sydney, Australia.

Ayse Tuba Altug

Department of Orthodontics, Faculty of Dentistry, Ankara University, Ankara, Turkey.

M Ali Darendeliler

Discipline of Orthodontics and Paediatric Dentistry, Sydney Dental School, Faculty of Medicine and Health, University of Sydney, Sydney, Australia.