Microimplant-assisted rapid palatal expansion appliance to orthopedically correct transverse maxillary deficiency in an adult

• We examined the effectiveness of a novel design for a microimplant-assisted rapid palatal expansion.
• We developed a standard protocol for microimplant-supported expansion.
• Implant-supported expansion offers vertical control and limits dental side effects.
• Orthopedic expansion is possible beyond the age previously thought possible.

This case report describes the use of a microimplant-assisted rapid palatal expansion (MARPE) appliance to orthopedically correct a transverse maxillary deficiency in an adult patient. Expansion forces transmitted through the teeth in traditional rapid palatal expansion appliances create unwanted dental effects rather than true skeletal expansion, particularly in older patients with more rigid interdigitation of the midpalatal suture. This 19-year-old patient had maxillary constriction with a unilateral posterior crossbite. A MARPE appliance secured to the palatal bones with 4 microimplants was expanded by 10 mm. Pre-MARPE and post-MARPE cone-beam computed tomography cross sections demonstrated 4 to 6 mm of expansion of the maxillofacial structures, including the zygoma and nasal bone area, and widening of the circummaxillary sutures. Minor buccal tipping of the dentition was observed, but the integrity of the alveolar bone was preserved. This report demonstrates that careful design and application of the MARPE appliance can achieve successful transverse expansion of the maxilla and the surrounding structures in a patient beyond the age typically considered acceptable for traditional rapid palatal expansion.