Cephalometric evaluation of molar distalization by hyrax screw used in conjunction with a lip bumper.
OBJECTIVE
To determine the treatment effects of the Hyrax screw, when used with a lip bumper appliance, on the distalization of maxillary molars and the reciprocal effects on the anchor premolars and maxillary incisors.


METHODS
Records, including study casts, lateral cephalometric radiographs, extra- and intraoral photographs of 9 patients were taken at the start of treatment and after distalization was achieved. Wilcoxon signed rank test was performed to analyze the skeletal and dental changes.


RESULTS
During the active period of maxillary molar distalization, the maxillary incisors significantly proclined by 5.89 degrees (P <.05), 5.39 degrees (P <.05), and 1.72 mm (P <.05) relative to the SN, RH, and RV planes, respectively. The maxillary first molars showed significant distal crown tipping, as evidenced by 4.61-degree (P = .00), 4.17-mm (P = .00), and 1.11-mm (P = .02) decreases in U6-RH angle, U6 perpendicular RV, and U6 perpendicular RH distances respectively. Anchorage loss, with 4.17 mm mesial movement of the maxillary second premolars, was significant (P = .01).


CONCLUSIONS
When selecting the appropriate method for maxillary molar distalization, anchorage loss potential, the need for patient compliance, and the duration of treatment should be considered.
Kucukkeles
Nazan
N
Marmara University, Department of Orthodontics, Faculty of Dentistry, Istanbul, Turkey. nazles@tnn.net
Cakirer
Banu
B
Mowafi
Mohammed
M
D000293:Adolescent; D002508:Cephalometry; D002648:Child; D003799:Dental Stress Analysis; D005260:Female; D006801:Humans; D008046:Lip; D008297:Male; D008437:Maxilla; D008963:Molar; D052280:Orthodontic Anchorage Procedures; D016382:Orthodontic Appliance Design; D009967:Orthodontic Appliances; D023861:Photography, Dental; D018709:Statistics, Nonparametric; D014087:Tooth Movement Techniques / Q000295:instrumentation*; D016896:Treatment Outcome