Simultaneous labial and lingual augmented corticotomy increase periodontal hard and soft tissues in 10 skeletal Class II patients - A preliminary study.

Background/purpose: During pre-orthognathic orthodontic procedures in skeletal Class II patients, mandibular anterior tooth retraction could cause depletion of periodontal tissues on the labial and lingual sides. This study aimed to assess the changes in alveolar bone thickness, gingival thickness and keratinized gingiva width of the mandibular anterior teeth after labial and lingual augmented corticotomy (LLAC). Materials and methods: 10 patients suffering from skeletal Class II malocclusion undergoing orthodontic-orthognathic combined treatment were included and LLAC was performed on their mandibular anterior teeth at the same time. Cone-beam computed tomography (CBCT) was performed at preoperatively (T0), 14 days postoperatively (Ts), and 6 months postoperatively (T1). Intraoral scanning was used at T0 and T1. The alveolar bone thickness, gingival thickness, keratinized gingiva width, and their changes were measured and analyzed. Results: At 6 months after LLAC, the mean labial and lingual alveolar bone thicknesses were 0.91 ± 1.19 mm and 1.43 ± 1.52 mm at T0 and 1.96 ± 1.59 mm and 2.24 ± 1.75 mm at T1. The mean increase in thickness of the labial and lingual gingiva was 0.44 ± 0.46 mm and 0.28 ± 0.45 mm. The mean keratinized gingiva width was 3.92 ± 1.55 mm at T0, and the mean width was 4.79 ± 1.38 mm at T1. There was a significant increase in periodontal soft and hard tissues at all measured sites postoperatively. Conclusion: LLAC procedure improves the periodontal phenotype of skeletal Class II during decompensation. It provides adequate tooth movement distance during preoperative pre-orthognathic orthodontic treatment and ensures that healthy periodontal tissues are obtained during that period.