Effects of mandibular protraction appliance-IV in the treatment of class II malocclusion: A cephalometric investigation

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 treatment 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 signiflcantly restricted the forward growth of maxilla (p<0.05). The appliance had no effect on the mandibular growth enhancetnent. Sagittal skeletal relationship improvement was significantly more in the treatment group subjects (p<0.01). Distul movcmcnt 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 subjects (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 tronted with mandibular protraction appliance IV.