Treatment effects of twin-block and mandibular protraction appliance-IV in the correction of class II malocclusion.
OBJECTIVE
To evaluate the treatment effects of twin-block and Mandibular Protraction Appliance-IV (MPA-IV) in the treatment of Class II division 1 malocclusion.


METHODS
Fifty North Indian girls with Class II division 1 malocclusion, in the age range of 9-13 years, were chosen. The subjects were divided among a control group (n = 10), a twin-block group (n = 25), and an MPA group (n = 15). Pre-follow-up and post-follow-up lateral cephalograms of control subjects and pretreatment and posttreatment lateral cephalograms of the treatment subjects were traced manually and subjected to a pitchfork analysis.


RESULTS
Neither twin-block nor MPA-IV significantly restricted the forward growth of maxilla. Mandibular growth and improvement in the sagittal skeletal relation were significantly greater in the twin-block subjects. Distal movement of the maxillary dentition and mesial movement of the mandibular dentition were more prominent in the MPA-IV subjects. Molar correction and overjet reductions were significantly greater in the treatment subjects (P < .001).


CONCLUSIONS
Twin-block and MPA-IV were effective in correcting the molar relationships and reducing the overjet in Class II division 1 malocclusion subjects. However, twin-block contributed more skeletal effects than MPA-IV for the correction of Class II malocclusion.
Jena
Ashok Kumar
AK
Oral Health Sciences Centre, Post Graduate Institute of Medical Education and Research, Chandigarh, India. ashokkjena@yahoo.co.in
Duggal
Ritu
R
D000293:Adolescent; D002508:Cephalometry; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007180:Incisor / Q000473:pathology; D008312:Malocclusion, Angle Class II / Q000473:pathology / Q000628:therapy*; D008334:Mandible / Q000254:growth & development / Q000473:pathology; D019186:Mandibular Advancement / Q000295:instrumentation; D008437:Maxilla / Q000254:growth & development / Q000473:pathology; D008963:Molar / Q000473:pathology; D016382:Orthodontic Appliance Design; D017289:Orthodontic Appliances, Functional; D063173:Retrognathia / Q000473:pathology / Q000628:therapy; D014087:Tooth Movement Techniques / Q000295:instrumentation; D016896:Treatment Outcome