Clockwise and Counterclockwise Le Fort I Movements Influence Nasolabial Morphology Differently

Purpose: Le Fort I advancement impacts nasal appearance. However, no data exists assessing 3D nasal change following anterior (counterclockwise, CCW) or posterior maxillary impaction (clockwise, CW) during Le Fort I osteotomy.  The purpose of this study was to analyze nasolabial changes comparing CW to CCW maxillary movements.

Materials and Methods: This was a retrospective cohort study of patients undergoing single-piece Le Fort I advancements.  Patients were split into two groups: CCW and CW. Pre- and postoperative 3D photographs (Canfield, Fairfield, NJ) were captured and anthropometric measurements were performed (>6mo postoperative).  Two observers verified each landmark. Statistical analysis involved paired t test for comparison of numerous pre- and postoperative nasolabial measurements for each patient in each group.

Results: Thirty patients were evaluated, 15 per group.  CCW had statistically significant increases in alar width (3.6mm, P<0.001), alar base width (1.6mm, p=0.009), oral width (3.1mm, P=0.02), and lip projection (+3.3mm, P=0.04). The subnasion projection (2.3mm, p=0.08) and columella width (0.58mm, P=0.9) demonstrated trends toward significant increases.  There were decreases in the nasofrontal angle (-3.05mm, p=0.10), nasolabial angle (-3.2mm, p=0.5), nostril height (-0.68mm, p=0.24), columella height (-0.11mm, p=0.88), philtrum height (-0.08, p=0.94) but these did not achieve statistical significance.  CW changes were not statistically significant.  However, the largest changes in positions were noted in alar width (2.7mm, p=0.07) and alar base width (1.7mm, p=0.09).  Decreases in the nasofrontal angle (-2.36, p=0.37), nostril height (-0.9mm, p=0.09), and columella height (-0.8mm, p=0.31) were noted.

Conclusion: 3D nasolabial changes are more marked for CCW movements.  This study suggests that soft-tissue nasolabial changes following Le Fort I are more complex than previously thought, and occlusal plane alteration significantly influences nasal form.    

Metzler P, Geiger EJ, Chang CC, Steinbacher DM.  Surgically assisted maxillary expansion imparts three-dimensional nasal change.  J Oral Maxillofac Surg. 2014 Oct;72(10):2005-14

Metzler P, Geiger EJ, Chang CC, Sirisoontorn I, Steinbacher DM. Assessment of three-dimensional nasolabial response to Le Fort I advancement.  J Plast Reconstr Aesthet Surg. 2014 Jun;67(6):756-63.