Comparison of Skeletal Anchorage Versus Conventional Tooth-Borne Face Mask Therapy Following the Alt-RAMEC Protocol

Skeletal Class III malocclusion with maxillary deficiency can negatively affect facial profile, occlusal function, and craniofacial growth. Early orthopedic intervention may help redirect growth and improve skeletal relationships. The Alternate Rapid Maxillary Expansion and Constriction (Alt-RAMEC) protocol has been introduced to enhance maxillary protraction by promoting greater disarticulation of the circummaxillary sutures.

In this prospective study, participants were randomly assigned to one of two treatment groups. Both groups used the same sequence of Alt-RAMEC activation over approximately seven weeks. In the skeletal anchorage group, miniscrews (2×11 mm) were placed in the zygomatic buttress region to directly apply orthopedic forces to the maxilla. In the conventional group, protraction forces were applied from hooks on a tooth-borne maxillary expansion appliance. In both groups, face mask therapy was performed with approximately 400 g of bilateral force applied at a 30-degree angle to the occlusal plane, worn 18-20 hours per day until a positive overjet was achieved.

Standardized lateral cephalometric radiographs were obtained at three time points: before treatment, after completion of the Alt-RAMEC protocol, and after completion of face mask therapy. Skeletal and dentoalveolar measurements were used to assess treatment effects. Primary outcomes focused on the forward movement of the maxilla, while secondary outcomes evaluated maxillary incisor inclination, molar position, mandibular rotations, and overjet correction.

This study aimed to clarify whether skeletal anchorage results in greater skeletal maxillary advancement and reduced dental compensation compared with conventional tooth-borne anchorage during facemask therapy in growing Class III patients.

Inclusion criteria

• Age between 7 and 13 years.
• Skeletal Class III malocclusion with maxillary retrognathia (ANB < 0°).
• Normal or increased vertical growth pattern (SN-GoGn < 39°).
• Retrusive nasomaxillary region and/or upper lip.
• Good oral hygiene.
• No contraindication for orthodontic treatment.
• Written informed consent obtained from parents/guardians.

Exclusion criteria

• Systemic diseases or conditions affecting bone metabolism.
• Craniofacial syndromes or congenital anomalies.
• Functional Class III due to habitual occlusal interference.
• Previous orthodontic or orthopedic treatment.
• Severe mandibular prognathism without maxillary involvement.