Effects of unilateral molar distalization with a modified pendulum appliance.
BACKGROUND
The purpose of this study was to evaluate skeletal and dentoalveolar changes due to unilateral distalization and to determine side effects.


METHODS
Cephalograms and dental casts before and after distal movement of the maxillary molars with pendulum appliances in 15 consecutively treated patients (5 girls and 10 boys, 12.06 +/- 1.32 years), were included in this study. The duration of distalization was 8.46 +/- 2.23 months.


RESULTS
Cephalometric analysis showed no remarkable growth between the 2 measurement times. The mean value for distalization of the first molars was 3.83 +/- 1.09 mm, with distal tipping of 6.45 degrees . The maxillary second molars were also moved distally 2.83 +/- 1.32 mm and tipped distally 14.7 degrees . No significant changes in the position of the third molars were measured. The mean reciprocal mesial movement of the premolars was 1.18 +/- 1.31 mm, with distal tipping of 1.94 degrees . The incisors moved 0.84 +/- 0.79 mm mesially, with mesial tipping of 0.02 degrees and extrusion of 1.21 mm. There was also a significant influence on the contralateral anchorage unit. However, unilateral distalization reduced incisor proclination and induced moderate distal movement of the contralateral anchorage unit based on rotation around a virtual axis perpendicular to the Nance button.


CONCLUSIONS
Effective distal molar movement and less anchorage loss at the front teeth are advantages of unilateral distalization.
Schütze
Stefan F
SF
Department of Orthodontics, Technical University of Dresden, Dresden, Germany.
Gedrange
Tomas
T
Zellmann
Markus R
MR
Harzer
Winfried
W
D000202:Activator Appliances / Q000009:adverse effects*; D000293:Adolescent; D002508:Cephalometry / Q000379:methods; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008310:Malocclusion / Q000628:therapy*; D008437:Maxilla / Q000254:growth & development; D003765:Models, Dental; D008963:Molar / Q000000981:diagnostic imaging; D052280:Orthodontic Anchorage Procedures / Q000295:instrumentation* / Q000379:methods; D009969:Orthodontic Wires; D011859:Radiography; D012189:Retrospective Studies; D012399:Rotation; D013997:Time Factors; D014087:Tooth Movement Techniques / Q000009:adverse effects* / Q000295:instrumentation