Combined rapid maxillary expansion and protraction facemask in the treatment of Class III malocclusions in growing children: a prospective long-term study.
A prospective study of 28 growing children (mean age of 8 years 3 months) with Class III malocclusions was consecutively treated using rapid maxillary expansion and maxillary protraction. All patients were treated from a negative overjet to a positive overjet and from a Class III dental malocclusion to a Class I dental relationship. For each patient, a lateral cephalogram was taken before treatment (T1), immediately posttreatment (T2), and after an observation period (T3) averaging 2 years 5 months. Using analysis of variance, the cephalograms were analyzed to determine skeletal and dental changes resulting from treatment. Long-term changes (2 years 5 month observation period) were also evaluated. Results showed that immediately posttreatment, the maxilla moved anteriorly a mean of 1.54 mm and Sella-Nasion-A point increased 0.87 degree. The maxillary teeth moved anteriorly 2.73 mm and proclined 5.23 degrees, while the mandible rotated in a downward and backward direction. Long-term, the anterior position of the maxilla was maintained, but some of the Class III correction was lost because of mandibular growth. Comparison of this study's results to Riolo's longitudinal Class I data showed that, overall, rapid palatal expansion and maxillary protraction produced a small orthopedic effect with a moderate dentoalveolar effect which together contributed to the correction of the Class III malocclusion.
Williams
M D
MD
Department of Orthodontics, University of Alabama at Birmingham 35294, USA.
Sarver
D M
DM
Sadowsky
P L
PL
Bradley
E
E
D000293:Adolescent; D002508:Cephalometry / Q000706:statistics & numerical data; D002648:Child; D002675:Child, Preschool; D005115:Extraoral Traction Appliances; D005260:Female; D006801:Humans; D008297:Male; D008313:Malocclusion, Angle Class III / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D008437:Maxilla / Q000254:growth & development*; D009972:Orthodontics, Interceptive / Q000379:methods*; D010155:Palatal Expansion Technique; D011446:Prospective Studies; D013997:Time Factors; D016896:Treatment Outcome