Functional and aesthetic results of the Z-shaped and straight lower lip-splitting incision: a randomized clinical trial

The lip-splitting approach enables excellent access to all areas of the mouth and pharynx to remove tumors; however, traditional lower lip-splitting incisions produce an unsatisfactory scar. To achieve better functional and aesthetic results, we used a Z-shaped incision and compared the functional and aesthetic outcomes of the straight and Z-shaped incisions. Sixty patients who fulfilled the inclusion criteria were randomly divided into two groups and underwent lip-splitting between March 2021 and September 2023. Eventually, 77 patients were reviewed within 6 months and evaluated using the lip function assessment scale, patient and observer scar assessment scale, naïve observer scar assessment scale, and a clinical examination. The Z-shaped incision group performed better in terms of the lip pout movement at 3 months and in the subjective overall opinion, color, irregularity, and pigmentation at 6 months. The Z-shaped incision group had a lower incidence of notched vermilion. In conclusion, Z-shaped lower lip-splitting incisions have better functional and aesthetic outcomes than traditional straight incisions.Trial registration: Public title: Difference between the effect of Z-shaped and vertical incisions of labiobuccal flap on the recovery of lower lip scars. Registration date: 09/03/2021. Registration number: ChiCTR2100044084. Registry URL: http://www.chictr.org.cn .