title: A long-term study on the expansion effects of the cervical-pull facebow with and without rapid maxillary expansion.
abstract: This study evaluates the long-term stability of maxillary expansion achieved by widening the inner bow of a facebow, with or without concurrent rapid maxillary expansion (RME) (Haas type), followed by treatment with fixed edgewise appliances. The parent sample included 154 nonextraction patients who started their orthodontic treatment during a defined time period. The exclusion criteria reduced the number of patients to 61 in the cervical-pull facebow group (CFB) and 41 in the RME-CFB group. All subjects were in the late-mixed to early-permanent dentition stage at the start of treatment. Dental casts were measured using a digital imaging system at four different times: start of treatment (T1), end of active treatment (T2), end of retention (T3), and postretention follow up (T4). The RME-CFB protocol produced a greater increase in maxillary arch width (6.1 mm) than did the CFB protocol (4 mm). The RME-CFB protocol provided greater net maxillary arch perimeter increase than did expansion with an inner bow of a cervical facebow. The RME-CFB group had three mm more arch perimeter 10 years after treatment completion than did the CFB group. The stability of expansion achieved with an inner bow of a facebow was equal to that achieved with a Haas-type RME appliance. Both expansion protocols retained 90% of the initial intermolar expansion 15 years after expansion.
authors.affiliation: The University of Michigan, Ann Arbor, Michigan, USA.
authors.forename: Frederick A
authors.initials: FA
authors.lastname: Fenderson
authors.forename: James A
authors.initials: JA
authors.lastname: McNamara
authors.forename: Tiziano
authors.initials: T
authors.lastname: Baccetti
authors.forename: Charles J
authors.initials: CJ
authors.lastname: Veith
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D002508:Cephalometry; D002648:Child; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008310:Malocclusion / Q000628:therapy; D008334:Mandible / Q000033:anatomy & histology*; D008437:Maxilla / Q000033:anatomy & histology*; D009967:Orthodontic Appliances; D009971:Orthodontics, Corrective / Q000295:instrumentation / Q000379:methods / Q000706:statistics & numerical data; D010155:Palatal Expansion Technique / Q000295:instrumentation*; D018579:Patient Selection; D014087:Tooth Movement Techniques / Q000295:instrumentation