During orthodontic decompensation in skeletal Angle Class III patients, a disruption of the periodontal tissues on the labial and lingual sides often occurs. This study aimed to assess the changes in the periodontal tissues of the mandibular anterior teeth after simultaneous labial and lingual augmented corticotomy (LLAC) surgery by digital measurements.The present study enrolled 11 adult patients with skeletal Class III malocclusion, with a total of 66 anterior teeth, who underwent LLAC surgery. Cone-beam computed tomography (CBCT) and intraoral scanning were obtained before surgery, at the immediate postoperatively and at 6 months postoperatively. The gingival thickness, keratinized gingiva width and alveolar bone thickness were measured.The mean labial and lingual gingival thicknesses were 0.51 ± 0.31 mm and 0.66 ± 0.48 mm preoperatively, and 0.80 ± 0.42 mm and 0.84 ± 0.66 mm at 6 months after LLAC. The mean keratinized gingiva width was 3.10 ± 1.20 mm preoperatively and increased by 0.65 ± 0.66 mm at 6 months after LLAC. The mean labial and lingual alveolar bone thicknesses were 0.84 ± 1.05 mm and 1.57 ± 1.65 mm preoperatively, and 2.28 ± 1.43 mm and 2.38 ± 1.58 mm at 6 months after LLAC. The patients showed significant increases in periodontal soft and hard tissues after surgery. In addition, there was a significant negative correlation between the gain of alveolar bone and gingival thickness.LLAC could increase periodontal soft and hard tissue, including gingival thickness, keratinized gingiva width and alveolar bone thickness to provide more stable and healthier periodontal tissue for patients with insufficient alveolar bone thickness during orthodontic treatment.© 2025 Association for Dental Sciences of the Republic of China. Publishing services by Elsevier B.Vé.