Adult Class III treatment using a J-hook headgear to the mandibular arch.
OBJECTIVE
To evaluate the treatment effects of high-pull J-hook headgear on the lower dental arch in nongrowing Class III patients.


METHODS
Fourteen nongrowing Class III patients having an Angle Class III malocclusion and ANB angle of less than 1.0 degree, were treated with high-pull J-hook headgear to the lower arch. Using lateral cephalograms and plaster models obtained before treatment (T1), after active treatment (T2), and after the retention period (T3), the treatment outcome was analyzed.


RESULTS
The incisal edge of the lower central incisor moved a mean of 1.2 mm to the lingual and 1.7 mm to the occlusal between T1 and T2. The axis of the lower incisor inclined 4.0 degrees to the lingual. The lower first molar cusp moved 1.5 mm to the distal and the root apex moved 2.0 mm to the mesial. Molar angulations were tipped 9.8 degrees to the distal. The occlusal plane showed 4.5 degrees counterclockwise rotation. The mean intermolar width increased 1.5 mm on average. Comparison of the records between T2 and T3 showed minimal changes.


CONCLUSIONS
Distal movement of the lower dental arch using J-hook headgear was clearly demonstrated, confirming that the application of high-pull J-hook headgear to the lower arch was effective for improvement of the Class III occlusion.
Kuroda
Yasuko
Y
kuroda@dent.tokushima-u.ac.jp
Kuroda
Shingo
S
Alexander
Richard G
RG
Tanaka
Eiji
E
D002508:Cephalometry; D005115:Extraoral Traction Appliances; D005260:Female; D006801:Humans; D008297:Male; D008313:Malocclusion, Angle Class III / Q000628:therapy*; D009971:Orthodontics, Corrective / Q000295:instrumentation*; D018709:Statistics, Nonparametric; D016896:Treatment Outcome; D055815:Young Adult