Analysis of inferior nasal morphology and nostrils following Le Fort I osteotomy

Objective: This study aimed to investigate the soft tissue parameters related to inferior nasal morphology and nostril shape and investigate the change at nostril types according to the Modified Topinard System following maxillary surgery. Materials and Methods: Thirty-five patients who underwent Le Fort I osteotomy with or without mandibular osteotomy were included in this retrospective study. Presurgery (T1) and postsurgery (T2) measurements which were the angle between the longitudinal axis of left and right nostril, nostril length, nostril width, alar width, alar base width, columella length, and columella width, were measured on computed tomography images. Nostril types according to Modified Topinard System and nostril shapes were also examined. Results: Following Le Fort I surgery, there was a significant increase in alar base width, alar width, and angle between the longitudinal axis of the left and right nostril (P<0.05). Nasal tip protrusion was decreased with significance (P=0.022). Multiple linear regression analysis showed that every 1 mm maxillary impaction amount leads to a 3.34 degrees increase in the angle between the longitudinal axis of the left and right nostrils (P=0.03, adjusted R (2)=0.21). Nostril type classification according to Modified Topinard System was changed significantly (P=0.000). Conclusion: Surgeons should be aware of the risk of postoperative nonaesthetic results in Modified Topinard System's borderline cases. Modified Topinard classification may be included in preoperative orthognathic planning from the bottom view.