Effects of Miniscrew-Assisted Rapid Palatal Expansion (MARPE) on the Facial Soft and Hard Tissues: A Correlation Study

Background: Miniscrew-assisted rapid palatal expansion (MARPE) has been introduced to correct maxillary constriction in post-pubertal patients. The effect of MARPE treatment on hard and soft facial tissues had been recognized in the main stream research. However, the evidence about correlation between these changes is still lacking. Objective: To determine the effects of MARPE on hard and facial soft tissues and to test the correlation between both variables. Methods: This prospective longitudinal study comprised 34 patients aged 16 to 24 years, with maxillary transverse discrepancy due to maxillary constriction. The MARPE expander (Moon design) with a lingual extension over the palatal surfaces of upper teeth was delivered with 4 micro-implants. Hard tissue dimensions were assessed using cone-beam computed tomography (CBCT) while facial soft tissues were assessed using a 3-dimensional digital stereophotogrammetry. Results: At the nasal level, pyriform aperture width increased by 3.18 mm ( P = .028), alar base width increased by 3.52 mm ( P = .007), and alar base root width increased by 2.27 mm ( P = .020). At the level of maxilla, anterior maxillary basal width increased by 2.44 mm ( P = .037) wile anterior maxillary basal width did not show significant difference ( P = 0118). Inter zygomatic maxillay distance increased by 3.74 mm ( P = .033). However, the effect of MARPE on mouth, mandible, and facial height was minimal ( P > .05). Pyriform width had strong positive correlation with alar base width ( r = .76, P = .030) and anterior maxillary basal width had strong positive correlation alar base root width as well ( r = .83, P = .004). Conclusion: RME produced significant increase in the nasal hard and soft tissue width with a significant positive correlation between both variables. Clinicians should thoroughly explain the anticipated changes to patients before MARPE initiation.