Comparative Evaluation of Three-dimensional Skeletal and Dentoalveolar Effects of Sawangi Flexiforce Expander and NiTi Expander in Class II (vertical) Cases with Maxillary Constriction: A Research Protocol

Abstract

Introduction: Maxillary constriction is a very common type of malocclusion found at any age. It is recommended to treat it as early as possible to avoid the worsening of the situation and to re-establish optimal function and aesthetics. Expansion of the maxillary arch is considered the best treatment procedure in a growing child. There are various appliances used for the expansion of the arch. The Nickel Titanium (NiTi) expander is considered the hallmark in orthodontics, but it has a few drawbacks. To overcome these drawbacks, the Sawangi Flexiforce Expander (SFE) has been introduced. The present study aims to evaluate and compare the effects of SFE against NiTi expander. Need for the study: The commercially available NiTi expander is very expensive. As most dental practices are located in rural areas, not every patient requiring arch expansion can afford it. Therefore, there is a need for an appliance that is as effective as the NiTi expander but affordable for everyone. Aim: To evaluate and compare the three-dimensional skeletal and dentoalveolar effects of SFE against the NiTi expander in class II (vertical) cases with maxillary constriction using the Finite Element Method (FEM). Materials and Methods: The present FEM study will be conducted in the Department of Orthodontics and Dentofacial Orthopaedics at Sharad Pawar Dental College in Wardha, Maharashtra, India. The study will take place from November 2023 to October 2024. A single patient with a vertically growing pattern will be selected for a Computed Tomography scan (CT scan) of the Nasomaxillary complex based on inclusion and exclusion criteria. The CT scan of the patient will then be converted into a 3D finite element model. The 3D models of the NiTi expander, SFE, and nasomaxillary complex will be studied to evaluate and compare the three-dimensional effects. Parameters such as stress distribution and displacement at skeletal, dental, and dentoalveolar landmarks of the nasomaxillary complex in three directions due to both expanders will be evaluated. An unpaired t-test will be used to determine significant differences between the two expanders and to compare the outcomes. The displacement at each landmark due to 1 mm of activation of both expanders will be correlated using the Pearson’s correlation test. A p-value <0.05 will be considered significant.

Keywords

• finite element method
• maxillary constriction
• posterior crossbite
• slow maxillary expansion
• sawangi flexiforce expander