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En masse retraction and two-step retraction of maxillary anterior teeth in adult Class I women. A comparison of anchorage loss.

OBJECTIVE
To compare the amount of anchorage loss of the maxillary posterior teeth and amount of retraction of the maxillary anterior teeth between en masse retraction and two-step retraction of the anterior teeth.


MATERIALS AND METHODS
The sample consisted of 30 female adult patients with Class I malocclusion and lip protrusion who needed maximum posterior anchorage. The sample was subdivided into group 1 (n = 15, mean age = 21.4 years, en masse retraction) and group 2 (n = 15, mean age = 24.6 years, two-step retraction). Lateral cephalograms were taken before (T1) and after treatment (T2). Nine skeletal and 10 anchorage variables were measured, and independent t-test was used for statistical analysis.


RESULTS
Although the amount of horizontal retraction of the maxillary anterior teeth was not different between the two groups, there was mild labial movement of the root apices of the upper incisors in group 2 at T2. There were no significant differences in the degree of anchorage loss of the maxillary posterior teeth between the two groups. Bodily and mesial movements of the upper molars occurred in both groups. Approximately 4 mm of the retraction of the upper incisal edges resulted from 1 mm of anchorage loss in the upper molars in both groups.


CONCLUSION
No significant differences existed in the degree of anchorage loss of the upper posterior teeth and the amount of retraction of the upper anterior teeth associated with en masse retraction and two-step retraction of the anterior teeth.