title: Comparison between rapid and mixed maxillary expansion through an assessment of dento-skeletal effects on posteroanterior cephalometry.
abstract: BACKGROUND
  The aim of this study is to compare the dento-skeletal effects of rapid maxillary expansion (RME) and mixed maxillary expansion (MME), assessed on posteroanterior (PA) cephalograms.
  
  
  METHODS
  Treatment groups consisted of 42 patients; mean age in RME group (n = 21,13 female and 8 male subjects) was 8.8 years ± 1.37 at T0 and 9.6 years ± 1.45 at T1 and mean age in MME group (n = 21, 12 female and 9 male patients) was 8.9 years ± 2.34 at T0 and 10.5 years ± 2.08 at T1. Seventeen bilateral anatomic landmarks, 16 linear (12 skeletal and 4 dental) and 4 angular measurements were assessed for each patient at T0 and T1. Data from the two groups were compared using independent sample t test (p < 0.05).
  
  
  RESULTS
  At T0, the groups were similar for all examined variables (p > 0.05). Significant and equal increase of lateronasal and maxillary and upper and lower molar widths (p < 0. 01) occurred in both groups at T1. Significant but different increases were observed for maxillary incisal, upper left first molar-lateroorbitale, and maxillary first molar angles (p < 0.001 vs. p < 0.05). Significant increases were reported for upper inter-incisal width apex (p < 0.001) and upper right first molar-lateroorbitale angle (p < 0.05) only in the RME group. At T1, differences in maxillary incisal angle (p < 0.05), upper left first molar-lateroorbitale, and maxillary first molar angles (p < 0.001) were noted.
  
  
  CONCLUSIONS
  RME and MME were both effective to increase skeletal transverse dimensions by opening mid-palatal suture in growing patients, while MME was associated with minor dental side effects than RME.
authors.forename: Letizia
authors.initials: L
authors.lastname: Perillo
authors.forename: Alfredo
authors.initials: A
authors.lastname: De Rosa
authors.affiliation: Department of Diagnostic Imaging, Second University of Naples, Via Luigi De Crecchio 6, Napoli, 80138, Italy. francescoiaselli@hotmail.it.
authors.forename: Francesco
authors.initials: F
authors.lastname: Iaselli
authors.forename: Fabrizia
authors.initials: F
authors.lastname: d'Apuzzo
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Grassia
authors.forename: Salvatore
authors.initials: S
authors.lastname: Cappabianca
mesh_terms: D059925:Anatomic Landmarks / Q000473:pathology; D002508:Cephalometry / Q000379:methods*; D002648:Child; D003724:Dental Arch / Q000473:pathology; D005147:Facial Bones / Q000473:pathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007180:Incisor / Q000473:pathology; D008297:Male; D008437:Maxilla / Q000473:pathology; D008963:Molar / Q000473:pathology; D009295:Nasal Bone / Q000473:pathology; D009915:Orbit / Q000473:pathology; D016382:Orthodontic Appliance Design; D010155:Palatal Expansion Technique / Q000295:instrumentation; D010159:Palate / Q000473:pathology; D012189:Retrospective Studies; D014070:Tooth / Q000473:pathology*