Change in Lower Lip Position After Le Fort I Advancement in Patients with Bilateral vs. Unilateral Cleft Lip and Palate.

To compare lower lip changes after Le Fort I advancement surgery in patients with a cleft. Single institution, retrospective review. Academic tertiary referral hospital. Skeletally mature patients with a cleft who underwent one-piece Le Fort I advancement surgery who had a lateral cephalogram or cone-beam computed tomography (CBCT) scan preoperatively and at least 6 months postoperatively. Patients who underwent concomitant mandibular surgery or genioplasty were excluded. 64 patients were included: 45 male and 19 female, 25 with BCLP and 39 with UCLP. The mean age at surgery was 18.4 years. Single jaw one-piece Le Fort I advancement surgery. Standard lateral cephalometric landmarks of the bony skeleton and soft tissue were compared before and after Le Fort I advancement. Pearson correlation coefficients (r) were calculated to measure the correlation between lower lip position and other soft and hard tissue changes. After comparable maxillary advancements [BCLP: 7.2 mm (95% CI: 6.2-8.3 mm), UCLP: 6.4 mm (95% CI: 5.7-7.0 mm)] the horizontal upper-to-lower lip discrepancy significantly improved in both groups. The lower lip became thinner and more posteriorly positioned. Changes in lower lip position correlated strongly with mandibular bony landmarks and moderately with upper lip position, but poorly with maxillary landmarks. Le Fort I advancement results in posterior displacement of the lower lip and better lip competence, thereby improving facial harmony. This lower lip change is not predictable by degree of maxillary advancement, and does not differ in patients with BCLP vs. UCLP.