Objective:To observe the clinical effect of free posterior interosseous artery perforator flap carrying superficial vein for reconstructing severe perioral scar hyperplasia and contracture.Methods:The retrospective observational study method was used. From August 2019 to March 2023, 11 patients with severe perioral scar hyperplasia and contracture after severe facial burns who met the inclusion criteria were admitted to General Hospital of TISCO (the Sixth Hospital of Shanxi Medical University). All patients were male and aged 23 to 56 years, with an average age of 31.3 years. After the perioral scar was removed and released, the wound area was 3.0 cm×2.0 cm to 10.5 cm×2.0 cm. The free posterior interosseous artery perforator flap carrying superficial vein was used to repair the wound, and the flap incision area was 3.5 cm×2.5 cm to 11.0 cm×2.5 cm. Among them, 6 patients required repair of wounds after resecting scar around ipsilateral upper and lower lips, and the lobular treatment of the flap was conducted. The wound in the flap donor area was directly sutured. After surgery, the survival of the flap and the occurrence of vascular crisis were observed. During follow-up after surgery, the appearance, texture, and color of the flap, the appearance of the flap donor area, and improvements of crooked mouth, drooling, limited mouth opening, and lip valgus in patients were observed.Results:All the flaps in patients completely survived after surgery, with no occurrence of vascular crisis. During follow-up of 6 to 36 months after surgery, the flap was not significantly bloated, was soft in texture, and had a similar color to that of the normal facial skin. Only linear scars were left in the flap donor area, and crooked mouth, drooling, limited mouth opening, and lip valgus in patients were significantly improved.Conclusions:The free posterior interosseous artery perforator flap carrying superficial vein can reconstruct severe perioral scar hyperplasia and contracture, with low incidence of postoperative flap vascular crisis, and the lobular treatment of flaps can repair wounds around unilateral upper and lower lips at the same time. After surgery, the appearance and function of the perioral area are significantly improved. The flap is a good choice for repairing small area of severe perioral scar hyperplasia and contracture.