Activation-deactivation rapid palatal expansion and reverse headgear in Class III cases

Abstract

The aim of this study was to evaluate and compare the dentofacial effects of 1 week rapid palatal expansion (RPE) and activation-deactivation (A/D) RPE protocols with reverse headgear (RH). Two groups, each containing 15 subjects, were included in this study. In the RPE group (seven males and eight females, 11.94 ± 1.62 years), Hyrax screws were activated every 12 hours for 1 week. At the end of this period, RPE was stopped and the patients were instructed to wear the RH. In the A/D-RPE group (seven males and eight females, 11.34 ± 1.81 years), the screws were activated every 12 hours for 1 week. Subsequently, the screws were deactivated every 12 hours for 1 week followed by activation and deactivation for the following 2 weeks. After this protocol, the patients were instructed to use the RH. A total force of 700 g was applied to both groups for 16-18 hours/day for the first 3 months, for 12 hours/day for the second 3 months, and for 6 hours/day for the second 6 months. Lateral cephalometric films were taken before treatment (T1) and at the end of the first (T2) and second (T3) 6 months to evaluate the dentofacial changes. Intragroup differences of each landmark at T2-T1, T3-T2, and T3-T1 were analysed with a paired t-test (P < 0.016), and intergroup differences were compared with an independent t-test (P < 0.05). Anterior movement of point A (4.13 mm) for the A/D-RPE group was approximately twice of the RPE group (2.33 mm; P < 0.001). Backward movement of the mandible showed no significant difference between the groups. Anterior face height increases did not demonstrate significant differences between the groups. The pronounced anterior movement of point A demonstrates that the A/D-RPE procedure positively affects maxillary protraction.

Changes in pharyngeal airway dimensions and hyoid bone position after maxillary protraction with different alternate rapid maxillary expansion and construction protocols: A prospective clinical study

“…Increased skeletal effects of maxillary protraction with the Alt-RAMEC protocol can explain the significant increases of those variables in our study. In agreement with our findings, previous studies 19,23 reported increased skeletal effects of maxillary protraction with Alt-RAMEC in the maxilla when compared with those without Alt-RAMEC.…”

“…Although the efficiency of maxillary protraction with the Alt-RAMEC protocol has been widely investigated in the literature, [18][19][20][21]23,24 none of the previous studies have focused on pharyngeal effects of this method when used for the correction of maxillary retrusion. The groups were well matched for gender distribution, chronological ages, treatment durations, and initial craniofacial and pharyngeal airway measurements as statistically tested, and thus the effects of those factors on findings were eliminated.…”

“…Liou 18 introduced a method called alternate rapid maxillary expansion (Alt-RAMEC) protocol to increase the skeletal effects of maxillary protraction, and several clinicians [19][20][21] reported the increased skeletal effects of this method when performed prior to maxillary protraction. To our knowledge, none of the previous studies evaluated the effects of maxillary protraction with Alt-RAMEC protocol on pharyngeal airway dimensions and hyoid bone position.…”

Effectiveness of maxillary protraction using facemask with or without maxillary expansion: a systematic review and meta-analysis

“…After the screening process, 66 studies were assessed for more detailed analysis with 1982 excluded articles due to conflict with the general selection criteria and duplicate articles. Following full text evaluation, 22 studies [1,16,[36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55] were included in the systematic review process after exclusion of 44 articles (due to secondary, detailed exclusion criteria). After quality assessment and scoring, a meta-analysis including eight studies was provided [1, 16, 40, 45-47, 52, 55] (Fig.…”

“…Maxillary protraction with palatal expansion was used in seven studies including subgroups [16,40,[45][46][47]52]. Two studies evaluated the effect of face mask treatment with an alternating protocol of expansion and compression [40,55] (Table 3).…”