The Impact of Le Fort I Advancement and Widening on Nasiolabial Morphology

Abstract

Le Fort I osteotomy imparts significant changes to the nasolabial region. Past studies have relied on 2-dimensional (2D) data, and have not adequately distinguished between various Le Fort I subtypes. The purpose of this study was to 3-dimensionally (3D) analyze the changes to the nose and lip following Le Fort I comparing single-piece, expanded segmental, and surgically assisted expansion (SAME). We hypothesized that the type and magnitude of movement would influence the nasolabial morphology. A retrospective cohort study was performed including Le Fort I patients grouped as: 1) non-segmental straight advancement, 2) segmental with advancement and widening, 3) surgically assisted expansion, without advancement. 108 photogrammetric datasets were analyzed, including 46 single piece, 36 segmental, and 26 SAME. The male-to-female ratio was 0.5 (mean age, 23.5). 3D photos (Canfield, Fairfield NJ) from preoperative and greater than 6-months post-procedure were analyzed. Anthropometric landmarks were placed and measured by two independent observers. Statistical analysis involved both paired and unpaired t-tests (significance = P <0.05). Mean advancement was 5.8 (± 1.8) and 5.6 (± 2.3) for the single-piece and segmental groups respectively. Significant postoperative nasal changes were observed within each intragroup analysis. Cross-group analysis demonstrated the greatest increase in alar base width (Δ3.9± 1.6), alar width (Δ4.5± 1.4), nostril width (Δ1.6± 0.7), and soft triangle angle (Δ11.1± 4), all P < .05. Nasofrontal angle decreased within the single-piece group, while philtral width increased only among the segmentals. In conclusion, dramatic nasolabial changes occur following Le Fort I osteotomy. The 3D changes are discrete and differ depending on the osteotomy group subtype. This objective understanding permits more accurate surgical planning and patient counseling.