title: Skeletal, soft tissue, and airway changes following the alternate maxillary expansions and constrictions protocol.
abstract: OBJECTIVE
  To evaluate the skeletal, soft tissue, and airway effects of the alternate maxillary expansions and constrictions (Alt-RAMEC) protocol in prepubertal patients.
  
  
  METHODS
  The appliance containing a double-hinged expansion screw was applied to 20 patients with Class III skeletal malocclusion characterized by maxillary retrognathia. The mean age of the study group was 9 years and 8 months. The patients' parents were instructed to open the screw by 1 mm per day during the first week and to close it by 1 mm per day the week after. This alternate opening and closing was repeated for 9 consecutive weeks. Cone beam computed tomography records and three-dimensional photographs were taken before treatment and after 9 week of the Alt-RAMEC protocol.
  
  
  RESULTS
  Point A moved slightly forward (0.89 mm) and downward (0.92 mm) (P < .05). The average amount of expansion achieved at the level of point A was 5.54 mm (P < .05). Besides the maxilla, the expansive forces also affected the nasal bone, the zygomaticomaxillary and zygomaticotemporal sutures (P < .05). The soft tissue nasal width increased significantly. The airway volume of the anterior nasal compartment and the nasal cavity also increased (P < .05).
  
  
  CONCLUSIONS
  Slight forward movement of point A occurred with the Alt-RAMEC protocol. The expansion affected not only the maxilla but also other structures of the face. Significant cutaneous changes occurred in the paranasal area. Some significant increase in the upper airway volume was obtained.
authors.affiliation: a  Clinical Instructor, Department of Orthodontics, Faculty of Dentistry, Bezmialem Vakif University, Istanbul, Turkey.
authors.forename: Berza Sen
authors.initials: BS
authors.lastname: Yilmaz
authors.forename: Nazan
authors.initials: N
authors.lastname: Kucukkeles
mesh_terms: D059925:Anatomic Landmarks / Q000473:pathology; D002508:Cephalometry / Q000379:methods*; D002648:Child; D054893:Cone-Beam Computed Tomography / Q000379:methods; D003393:Cranial Sutures / Q000473:pathology; D005145:Face / Q000473:pathology*; D005147:Facial Bones / Q000473:pathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D008297:Male; D008313:Malocclusion, Angle Class III / Q000628:therapy*; D008437:Maxilla / Q000473:pathology; D009295:Nasal Bone / Q000473:pathology; D009296:Nasal Cavity / Q000473:pathology*; D009666:Nose / Q000473:pathology; D016382:Orthodontic Appliance Design; D010155:Palatal Expansion Technique / Q000295:instrumentation; D010614:Pharynx / Q000473:pathology*; D010781:Photography / Q000379:methods; D063173:Retrognathia / Q000628:therapy; D013701:Temporal Bone / Q000473:pathology; D015050:Zygoma / Q000473:pathology
keywords: Airway; Alt-RAMEC; Class III malocclusion; Double-hinged expansion screw