[A clinical study on effects of distalization of whole upper arch in borderline Class II malocclusion using microscrew anchorages in inferiozygomatic area].

PURPOSE: To investigate the effect of distalization of upper dentition using microscrew anchorages placed in inferiozygomatic area to correct borderline Class II malocclusion.

METHODS

Nine borderline Class II cases aged from 13-17 years old, with moderate convex profile were selected. All cases were designed to extract upper second molars or third molar germs to provide space for distalization of upper dentition using microscrew anchorages placed in inferiozygomatic area. Cephalometrics before and after treatment were compared to analyze the movement of upper morlars and incisors, as well as the position change of upper and lower lips. The data were analyzed by paired t test with SPSS17.0 Software package.

RESULTS

After an average of 14 months of treatment, all cases got improved profiles with correction of Class II dental relationship. The upper molars and incisors were pulled back 3.1 mm and 2.8 mm, respectively. No adverse root resorption or sinus infection caused by the microscrews was observed.

CONCLUSIONS

Microscrew anchorages placed in inferiozygomatic area can be used to correct borderline Class II malocclusion by distalization movement of upper dentition with a better profile and no adverse complication. Supported by Medical Guide Project of Science and Technology Committee of Shanghai Municipality (09411964900).