Microimplant Assisted Rapid Palatal Expansion: A Comprehensive Review

Maxillary transverse deficiency routinely requires expansion of the palate. In prepubertal patients, Rapid Maxillary Expansion (RME) is a reliable treatment modality. However, in skeletally mature patients due to progressively interdigitated mid palatal suture, decreased elasticity of bone and increased stiffness of the osseous articulations of the maxilla with the adjoining bones, palatal expansion becomes challenging. Patients are frequently suggested to opt for more invasive procedures, like the Surgically Assisted Rapid Palatal Expansion (SARPE). The quest for minimally invasive expansion appliances with pure orthopaedic movement led researchers to incorporate mini-implants with conventional RME. Microimplant Assisted Rapid Palatal Expansion (MARPE) maximises skeletal expansion and minimises dentoalveolar undesirable effects and obviates the need for orthognathic surgery. This comprehensive review aims to discuss MARPE as an effective, non surgical, minimally invasive treatment modality for skeletally mature patients with maxillary transverse insufficiency. Furthermore, various designs of MARPE with different placement sites, lengths, and numbers of miniscrews along with the latest technological advancements to improve diagnosis and treatment planning using CBCT and intraoral scan, as well as the use of Computer-Aided Design/Computer-Aided Manufacturing (CAD-CAM) technology to custom fabricate three dimensional (3D) miniscrew insertion surgical guide, 3D laser-printed metallic mini-implant to enhance implant placement accuracy and comfort were discussed along with the clinical significance and limitations of the MARPE. Maxillary Skeletal Expander (MSE) is a unique lineage of MARPE when combined with facemask results in distraction osteogenesis like movement of midface and forms a promising basis for non surgical orthopaedic treatment modality for skeletal class III mature patients. Bone-anchored maxillary expansion appliances provide better vertical control, especially beneficial for hyperdivergent skeletal pattern patients. MARPE significantly increases transverse widths of the nasal floor, nasopharyngeal volume and significantly lowers mean nasal airway resistance thereby facilitating nasal breathing. MARPE results in greater orthopaedic expansion and safety, with fewer undesirable effects and high success rates.