Comparative Three-dimensional Analysis of Philtral Ridge Projection in Unilateral Cleft Lip Repair enhanced with Muscle to sub-Dermis suture

Abstract

Introduction: Recreating the philtral ridge and restoring orbicularis oris muscle continuity in cleft patients is a challenging task. Our muscle to sub-dermis technique introduces an effective method for achieving the desired philtral ridge reconstruction. Method: From August 2015 to July 2023, a retrospective study was conducted with a follow-up period of at least 6 months. This procedure involved a suture technique using muscle-to-sub-dermis sutures. Measurements of philtral projection were taken at two distinct points: one above the cupid's bow and the other at the mid-philtral level. In the comparative analysis of philtral ridges between the cleft and non-cleft sides, the root mean square (RMS) projection value was assessed. Additionally, an analysis of the restoration of the orbicularis oris muscle included the use of color mapping from the mid-sagittal plane and covered seven different points across three distinct horizontal planes: below subnasale, at the mid-philtral level, and above the cupid's bow. Results: Total 134 patients were included with a 37.8-month follow-up(SD 9.4). Philtral side projection was well-maintained, measuring -0.36(0.43)mm, -0.24(0.49)mm on the classical group vs. 0.23(0.29)mm, 0.20(0.21)mm on the muscle to sub-dermis group(p=0.001). The RMS projection value was 0.57(0.46) vs. 0.14(0.046), indicating greater symmetry in the muscle to sub-dermis group, with no difference in sagittal vector analysis of the orbicularis oris muscle between normal and cleft sides. Conclusion: A suturing technique utilizing muscle to sub-dermis sutures has shown promising results in philtral projection and dimple formation. This improvement can be attributed to the combined effect of sub-dermis and less muscle sutures.