title: Nonsurgical miniscrew-assisted rapid maxillary expansion results in acceptable stability in young adults.
abstract: OBJECTIVE
  To evaluate the stability of nonsurgical miniscrew-assisted rapid maxillary expansion (MARME) in young adults with a transverse maxillary deficiency.
  
  
  METHODS
  From a total of 69 adult patients who underwent MARME followed by orthodontic treatment with a straight-wire appliance, 20 patients (mean age, 20.9 ± 2.9 years) with follow-up records (mean, 30.2 ± 13.2 months) after debonding were selected. Posteroanterior cephalometric records and dental casts were obtained at the initial examination (T0), immediately after MARME removal (T1), immediately after debonding (T2), and at posttreatment follow-up (T3).
  
  
  RESULTS
  Suture separation was observed in 86.96% of subjects (60/69). An increase in the maxillary width (J-J; 1.92 mm) accounted for 43.34% of the total expansion with regard to the intermolar width (IMW) increase (4.43 mm; P < .001) at T2. The amounts of J-J and IMW posttreatment changes were -0.07 mm (P > .05) and -0.42 mm (P  =  .01), respectively, during retention. The postexpansion change in middle alveolus width increased with age (P < .05). The postexpansion change of interpremolar width (IPMW) was positively correlated with the amount of IPMW expansion (P < .05) but not with IMW. The changes of the clinical crown heights in the maxillary canines, first premolars, and first molars were not significant at each time point.
  
  
  CONCLUSIONS
  Nonsurgical MARME can be a clinically acceptable and stable treatment modality for young adults with a transverse maxillary deficiency.
authors.affiliation: a  Fellow, Department of Orthodontics, Institute of Craniofacial Deformity, College of Dentistry, Yonsei University, Seoul, Korea.
authors.forename: Sung-Hwan
authors.initials: SH
authors.lastname: Choi
authors.affiliation: b  Postgraduate student, Department of Orthodontics, College of Dentistry, Yonsei University, Seoul, Korea.
authors.forename: Kyung-Keun
authors.initials: KK
authors.lastname: Shi
authors.affiliation: c  Associate Professor, Department of Orthodontics, Institute of Craniofacial Deformity, College of Dentistry, Yonsei University, Seoul, Korea.
authors.forename: Jung-Yul
authors.initials: JY
authors.lastname: Cha
authors.affiliation: d  Professor Emeritus, Department of Orthodontics, College of Dentistry, Yonsei University, Seoul, Korea.
authors.forename: Young-Chel
authors.initials: YC
authors.lastname: Park
authors.affiliation: e  Professor, Department of Orthodontics, Institute of Craniofacial Deformity, College of Dentistry, Yonsei University, Seoul, Korea.
authors.forename: Kee-Joon
authors.initials: KJ
authors.lastname: Lee
mesh_terms: D000293:Adolescent; D000328:Adult; D002508:Cephalometry; D003724:Dental Arch / Q000473:pathology*; D006801:Humans; D008437:Maxilla; D008963:Molar; D010155:Palatal Expansion Technique; D055815:Young Adult
keywords: Adults; MARME; Stability; Transverse maxillary deficiency