Effects of Mandibular Protraction Appliance-IV in the Treatment of Class II Malocclusion: A Cephalometric Investigation

Abstract

To evaluate the nature of Class II correction with MPA-IV in the:treatment of class II Division 1 malocclusions. Twenty-five subjects in the age range of 10-12 years were chosen for the study. The subjects were divided among control group (n=10) and teatment group (n=15). Prefollow-up and postfollow up lateral cephalograms of control subjects, and pretreatment and posttreatment, lateral cephalograms of the treatment subjects, were traced manually and subjected to the pitchfork analysis. MPA-IV significantly restricted the forward growth of maxilla (p<0.05). The appliance had no effect on the mandibular growth enhancement. Sagittal skeletal relationship improvement was significantly more in the treatment group subject (p<0.01). Distal movement of the maxillary dentoalveolar segments, mesial movement of the mandibular dentoalveolar segments; Class II molar correction and overjet correction were significantly more in the treatment subject. (p<0.001).

Conclusions: Mandibular protraction appliance IV was an effective fixed functional appliance in the correction of Class II Division 1 malocclusion. However, subjects who can tolerate greater dentoalveolar compensation for the correction of their Class II malocclusion. are best treated with mandibular protraction appliance IV.