Maxillary arch changes during leveling and aligning with fixed appliances and low-friction ligatures.
BACKGROUND
The aim of this study was to evaluate the changes in the transverse dimension and the perimeter of the maxillary arch produced by a low-friction system during the leveling and aligning phases of fixed appliance therapy.


METHODS
The low-friction protocol consisted of a combination of preadjusted brackets, superelastic nickel-titanium archwires, and nonconventional elastomeric ligatures; it was used in 20 consecutively treated patients with mild crowding.


RESULTS
Statistically significant increases were recorded for all dentoalveolar widths (with the exception of intermolar width measured lingually) and arch perimeter (3.5 mm on average). The increase in arch perimeter showed a significant negative relationship with the individual perimeter of the maxillary arch before treatment. No significant change was found for arch depth.


CONCLUSIONS
The low-friction system produced statistically significant increases in the transverse dentoalveolar width and the perimeter of the maxillary arch during the leveling and aligning phases of treatment with an average duration of 6 months.
Franchi
Lorenzo
L
Department of Orthodontics, University of Florence, Florence, Italy. l.franchi@odonto.unifi.it
Baccetti
Tiziano
T
Camporesi
Matteo
M
Lupoli
Massimo
M
D000293:Adolescent; D003722:Dental Alloys; D003724:Dental Arch / Q000033:anatomy & histology*; D003799:Dental Stress Analysis; D004548:Elasticity; D020724:Elastomers; D005260:Female; D017276:Friction; D006801:Humans; D016014:Linear Models; D008297:Male; D008310:Malocclusion / Q000628:therapy; D008437:Maxilla; D009532:Nickel; D009716:Numerical Analysis, Computer-Assisted; D016382:Orthodontic Appliance Design; D009967:Orthodontic Appliances; D016910:Orthodontic Brackets; D009969:Orthodontic Wires; D009971:Orthodontics, Corrective / Q000295:instrumentation* / Q000379:methods; D014025:Titanium
D003722:Dental Alloys; D020724:Elastomers; C040654:titanium nickelide; D009532:Nickel; D014025:Titanium