Evaluation of the Efficacy of Different Anchorage-supported Appliances and Different Expansion Procedures for Face Mask Treatment in Prepubertal Children

Face mask therapy is an effective method in the treatment of class III malocclusions due to maxillary insufficiency. In face mask treatment, various intraoral devices are used to transmit protraction forces to the maxilla. According to the anchorage unit, these appliances are divided into tooth-supported and bone-supported. The traditional bonded rapid maxillary expander (RME) is a tooth-supported appliance that allows expansion and is generally used with face masks. However, it causes many side effects due to the transmission of protraction forces through the teeth. Hybrid appliances supported by skeletal and dental anchorage may be preferred over bonded RME in the maxilla for face mask treatment based on their lower dental side effects and high skeletal contribution.

Before transferring the protraction forces to the maxilla using a face mask, expansion is first performed with intraoral devices according to the patient's needs. For this purpose, two different expansion procedures are currently used: routine rapid maxillary expansion (routine) and alternative rapid maxillary expansion and contraction (alt-RAMEC). In the routine rapid maxillary expansion procedure, the expander screw is turned twice a day until the expansion phase is complete. Unlike the routine procedure, in the alt-RAMEC procedure, each week of expansion is followed by a week of contraction. The duration of the expansion-contraction process varies between 7-9 weeks, depending on the patient's need for expansion. These opening and closing phases are increased maxillary protraction by loosening the intermaxillary sutures.

The main purpose of this study is to compare the effects of different combinations of appliances and procedures on maxillary protraction during face mask treatment and determine the most powerful method. Sixty patients who were planned to apply face mask treatment were included in the study and divided into four groups (n=15) (Group 1: Hybrid-Hyrax expander and alt-RAMEC procedure, Group 2: Bonded RME and alt-RAMEC procedure, group 3: Hybrid Hyrax expander and routine protocol, group 4: Bonded RME and routine protocol). To investigate skeletal changes, lateral cephalometric films were taken before (T0) and after (T1) treatment. Dolphin Imaging software and AutoCad 2023 software were used for cephalometric measurements.