Abstract: Objective To explore the clinical effects of single pedicle transfer of expanded axial flap across the midline of the frontal-parietal region in reconstruction of large scar deformities in the face and neck. Methods From January 2016 to August 2019, 10 male patients, aged from 20 to 52 years with post-burn facial and cervical scar deformities, were admitted to the First People′s Hospital of Zhengzhou, with the size of scar ranging from 15 cm×7 cm to 23 cm×11 cm. In the first stage, a cylindrical skin and soft tissue expander with rated capacity ranging from 400 to 600 mL was placed in the frontal-parietal region. Another cylindrical expander with rated capacity ranging from 50 to 100 mL was placed in the temporal region of the patient with scars in front of the ear and in cheek. The injection time was 3 to 5 months with the total injection volume being 1.5 to 2.5 times of the rated capacity of expander. In the second stage, the superficial temporal artery frontal branch and its branches were explored, the expander was removed, the scars in the face and neck were conducted resection and contracture relaxation, and the single pedicle transfer of expanded axial flap across the midline of the frontal-parietal region for reconstruction was performed. When the branches of the superficial temporal vessels were difficult to be detected by Doppler ultrasonic blood stream detector, the patient underwent computed tomography (CT) angiography and three-dimensional reconstruction. The donor site in frontal-parietal region was directly sutured, and the wound of the exposed donor site at the pedicle and temporal region was temporarily covered with scar skin. After the suture wound was healed and the hair in expanded flap grew out, hair removal and laser hair removal were performed. Three to four weeks after transplantation of expanded flap, the flap pedicle was cut off, restored, and trimmed in the third stage. The status about the completion of operation, the implantation of expander in the temporal region, CT angiography and three-dimensional reconstruction were recorded. The effective resection area of expanded flap, the length across the midline and the length of the pedicle, and the survival status of the expanded flap and complications after operation were observed. The appearance of donor and recipient sites, the scar recurrence, the appearance and function improvement of patients, and the satisfaction degree of patients were followed up. Results All the 10 patients successfully completed three stages of operation, of which 6 patients had an auxiliary expander placement in the temporal region, and 5 patients underwent CT angiography and three-dimensional reconstruction. The effective resection area of expanded flap ranged from 18 cm×8 cm to 25 cm×13 cm. The distal end of the flap across the midline extended 4-6 cm to the opposite side, and the length of pedicle was 2-6 cm. All the expanded flaps of patients survived well after formation and transfer. The venous reflux disorder and obvious swelling occurred in 6 patients at the distal end of the flap after operation, and the blood supply recovered after acupuncture bloodletting, etc. Follow-up of 6 to 24 months showed that the color, texture, and thickness of the expanded flaps were similar to those of the facial skin, and no recurrence of scar was observed; the incision in the donor site of the frontal-parietal region was concealed, the hair growth of the temples and head was normal, and the reconstructed hairline was natural; compared with those before operation, the appearance, head-up, mouth-opening, and other functions of patients were significantly improved; the patients were satisfied with the effect of reconstruction. Conclusions Clinical application of single pedicle transfer of expanded axial flap across the midline of the frontal-parietal region in reconstruction of large scar deformities in the face and neck can achieve a good appearance and function, and the donor site shows good shape, which enriches the application range of the trans-regional blood supply flap. It is a reliable method for reconstruction of large scar deformities in the face and neck.