Mandibular autorotation after maxillary multidirectional movement, an in vitro evaluation

Abstract

The aim of this study was to identify algorithms for predicting mandibular rotation following in vitro multiplanar maxillary
repositioning. Model surgery is useful for evaluating the final treatment outcome. The amount of mandibular rotation was
measured using a semi-adjustable articulator, allowing us to move the maxilla in multiple directions. We evaluated the
amount of mandibular rotation after every 1 mm increase in predetermined maxillary planning. The distance between a
point in the midline papilla between the central incisors and a predetermined base point on the vertical pin of the articulator
was used as the reference distance. Every change in mandibular rotation after maxillary displacement was measured
between the mentioned points to obtain the amount of mandibular displacement. Next, we used regression analysis to create
the necessary formulas. The greatest variation in mandibular rotation was seen in vertical displacement. According to the
results, the most reliable formulas are related to disimpaction, followed by impaction, setback, and advancement. This
method is simple and practical. Therefore, surgeons can use it while they plan for model surgery and predict the amount of
mandibular rotation after maxillary repositioning