Research progress on "sandwich" osteotomy to increase alveolar bone

Lack of alveolar bone height is a major challenge for dental implants. In recent years, the use of "sandwich" osteotomy to increase alveolar bone height has become a topic of discussion within the research community. In theory, "sandwich" osteotomy is a U-shaped osteotomy in the bone defect area, to preserve the blood supply of the mucoperiosteal on the lingual side and to create an artificial "four-wall bone bag" to build a favorable space for osteogenesis and to increase the height of the alveolar bone. Histological studies have shown that the osteogenesis speed of "sandwich" osteotomy is fast, and the bone is good. Sandwich osteotomy is suitable for buccal-lingual alveolar bone height defects less than 50% of the implant length or for unilateral defects more than 50% of the implant length. In the operation of "sandwich" osteotomy, the horizonal incision should be 10-12 mm below the crest of the buccal alveolar ridge. The design of the osteotomy line should ensure the height of the osteotomy block and that the mandibular canal does not sustain damage and that it fits the shape of the bone defect. There was no significant difference in the osteogenic effect of different types of bone graft materials used for "sandwich" osteotomy. The osteotomy block was rigorously fixed by a titanium plate, titanium nail, implant and other materials, and finally, the intraoperative area was tensioned and sutured. The effect of bone augmentation was evaluated and compared with other bone augmentation techniques; the evaluation showed that sandwich osteotomy was better for moderate vertical bone defects. This technique is highly sensitive and postoperative transient sensory loss is common. With advances in technology, the application of digital technology and ultrasonic bone knives, the risk of complications is greatly reduced and advances in digital osteotomy will promote apply of "sandwich" osteotomy, which will become a popularized technique for clinical alveolar bone augmentation.