Clinical and cone-beam computed tomography outcomes of miniscrew-assisted rapid palatal expansion in the treatment of maxillary transverse deficiency: A prospective study

This study evaluates skeletal and dental effects of miniscrew-assisted rapid palatal expansion (MARPE) in late adolescents and young adults with maxillary transverse deficiency. This prospective study enrolled 36 patients (12 males, 24 females; mean age 20.14 years) diagnosed with maxillary transverse deficiency and treated with a custom-made Hyrax-type MARPE anchored by 4 palatal miniscrews. The expansion protocol consisted of 2 daily activations (0.26 mm/day) until the desired expansion was achieved, followed by a 6-month retention period. Measurements were obtained at baseline (T0), post-expansion (T1), and post-retention (T2). The mean total expansion at the first molar level was 5.94 ± 3.57 mm, with 67.34% attributable to skeletal widening; and effective midpalatal suture separation was achieved. Nasal base width increased by 3.29 mm and nasal cavity width by 1.81 mm from T0 to T1, with minimal relapse at T2. Posterior maxillary segments showed both lateral and anterior displacement. Cephalometric parameters remained largely stable, indicating no adverse sagittal or vertical changes. Mild buccal tipping of alveolar segments was observed (first molar inclination change: right + 4.83°, left + 5.17° from T0 to T2). Upper first molars tipped buccally after expansion but showed partial relapse during retention. Buccal alveolar bone thickness decreased at molar and premolar levels, while palatal bone thickness increased, reflecting bone remodeling. MARPE in skeletally mature patients can achieve substantial skeletal expansion with controlled dental side effects, preserved vertical and sagittal relationships, and favorable nasal airway dimensional changes, supporting MARPE as a predictable, minimally invasive alternative in late adolescent patients.