Document Type


Date of Degree

Spring 2019

Degree Name

MS (Master of Science)

Degree In


First Advisor

Shin, Kyungsup

First Committee Member

Marshall, Steven D

Second Committee Member

Southard, Thomas E

Third Committee Member

Qian, Fang


Introduction: Treating adolescent maxillary constriction often includes a traditional RME appliance, with the aim of creating a separation of the midpalatal sutural (MPS). However, maxillary skeletal expansion becomes more difficult with age due to increased facial and mid-palatal, skeletal resistance. An emerging treatment option with the hopes of overcoming this skeletal resistance is a mini-screw assisted RME appliance. The purpose of this study is to evaluate the age and maturation at which successful separation of the maxillary MPS can be achieved, and whether or not this can be improved with the utilization of a mini-screw assisted RME appliance.

Materials and Methods: In this prospective clinical trial, N=96 (n=43 M, n=53 F) consecutively treated subjects exhibiting maxillary skeletal constriction underwent traditional RME treatment and N=13 (n=7 M, n=6 F) underwent MARME treatment utilizing mini-screws. Subjects were also classified into either pre-pubertal or post-pubertal groups based on maturation. Evidence of MPS separation was confirmed by the development of a diastema between upper central incisors and using a maxillary occlusal radiograph.

Results: Average age of the 96 subjects with traditional RME treatment was 13.8 years with 71.9% achieving successful separation of the maxillary MPS. Sutural separation occurred with traditional RME for 96% of the pre-pubertal group compared with 62% of the post-pubertal group. There was also a significantly strong negative correlation between age and percent ability to get MPS separation with traditional RME. In contrast, average age of mini-screw RME subjects was 17.1 years (n=13), all were classified as post-puberty, and MPS separation occurred 100% of the time.

Conclusions: Utilization of mini-screw assisted RME is a good option for clinicians when treating post-pubertal adolescents and early adult patients. However, MPS separation is highly likely to occur in pre-pubertal patients treated with traditional RME. As a result, patient age and maturation should be taken into account when deciding between traditional or mini-screw assisted RME treatment.


Maxillary Expansion


viii, 60 pages


Includes bibliographical references (pages 57-60).


Copyright © 2019 Clint Wire