Class III Malocclusion, Maxillary Deficiency, Skeletal Malocclusion
Conditions
Keywords
Face Mask Therapy, Growing Patients, Cephalometric Evaluation, Class III Orthodontic Treatment, Maxillary Protraction, Alt-RAMEC Protocol, Zygomatic Buttress Miniscrew, Miniscrew Anchorage, Skeletal Anchorage
Brief summary
This study investigated two different methods of maxillary protraction in growing patients with skeletal Class III malocclusion characterized by maxillary deficiency. All participants underwent the Alternate Rapid Maxillary Expansion and Constriction (Alt-RAMEC) protocol to mobilize the circummaxillary sutures. Following this, maxillary protraction was performed using either skeletal anchorage with miniscrews placed in the zygomatic buttress region or a conventional tooth-borne rapid maxillary expansion appliance. Cephalometric radiographs were taken before treatment, after the Alt-RAMEC protocol, and after completion of face mask therapy to evaluate skeletal and dentoalveolar changes. The study aimed to determine whether skeletal anchorage provides greater maxillary advancement and reduced dental side effects compared to conventional tooth-borne anchorage.
Detailed description
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.
Interventions
DEVICESkeletal Anchorage Supported Maxillary Protraction
Maxillary protraction using skeletal anchorage placed in the zygomatic buttress region following the Alt-RAMEC protocol. Two 2×11 mm miniscrews were inserted under local anesthesia, and protraction elastics delivering approximately 400 g of bilateral force at a 30° downward angle to the occlusal plane were attached to the face mask. Patients were instructed to wear the face mask for 18-20 hours per day until a positive overjet was achieved.
DEVICETooth-Borne Maxillary Protraction Appliance
Maxillary protraction performed using a Hyrax-type tooth-borne expansion appliance equipped with anterior hooks after completion of the Alt-RAMEC protocol. Face mask elastics delivering approximately 400 g of bilateral force at a 30° downward angle to the occlusal plane were attached to the appliance. Patients were instructed to wear the face mask for 18-20 hours per day until a positive overjet was achieved.
Sponsors
Murat Kaan Erdem
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Masking description
Treatment providers and participants could not be masked due to the nature of orthodontic appliances.
Intervention model description
Participants were randomly assigned to one of two parallel treatment groups: skeletal anchorage-supported face mask therapy or conventional tooth-borne face mask therapy.
Eligibility
Sex/Gender
ALL
Age
7 Years to 13 Years
Healthy volunteers
No
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.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in SNA Angle | From baseline to 10 months | The SNA angle measures the sagittal position of the maxilla relative to the cranial base. An increase in this value indicates forward movement of the maxilla. The change in SNA (in degrees) will be compared within each group and between treatment groups. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in A-Point to Vertical Reference Distance (A-Tvert.) | From baseline to 10 months | A-Tvert. measures the sagittal position of Point A relative to a vertical craniofacial reference plane. An increase in this distance indicates forward movement of the maxilla. The change will be compared within groups and between treatment groups to assess the skeletal effect of protraction. |
Countries
Turkey (Türkiye)
Outcome results
None listed