RAMPA Therapy: Impact of Suture Stiffness on the Anterosuperior Protraction of Maxillae; Finite Element Analysis

Objective: The material properties of craniofacial sutures significantly influence the outcomes of orthodontic treatment, particularly with newer appliances. This study specifically investigates how the Young’s modulus of craniofacial sutures impacts the anterosuperior protraction achieved using a recently developed extraoral appliance. Our goal is to identify the patterns by which suture properties affect skull deformation induced by this device. Materials and Methods: We conducted four finite element (FE) simulations to evaluate the Right Angle Maxillary Protraction Appliance (RAMPA) when integrated with an intraoral device (gHu-1). We tested Young’s moduli of 30 MPa, 50 MPa, and 80 MPa for the sutures, drawing on values reported in previous research. To isolate RAMPA’s effects on craniofacial deformation, we also performed an additional simulation with rigid sutures and a separate model that included only the intraoral device. Results: Simulations with flexible sutures showed consistent displacement and stress patterns. In contrast, the rigid suture model exhibited substantial deviations, ranging from 32% to 76%, especially in the maxillary palatine suture and orbital cavity. Both displacements and von Mises stresses were proportional to the Young’s modulus, with linear variations of approximately 15%. Conclusions: Our findings demonstrate that RAMPA effectively achieves anterosuperior protraction across a broad spectrum of suture material properties. This positions RAMPA as a promising treatment option for patients with long-face syndrome. Furthermore, the observed linear relationship (with a fixed slope) between craniofacial deformation and the Young’s modulus of sutures provides a crucial foundation for predicting treatment outcomes in various patients.