Abstract: The posterior crossbite is a common malocclusion characterized by abnormal buccal/lingual relationship between the maxillary and mandibular posterior teeth,which seriously affected the oclussal function, aesthetics, and oral health. There are multiple clinical manifestations, considering the distribution of medical resources, the orthodontist's technical level, and patient's wishes. It is hard to say that a correction method is perfectly suitable for a certain case. After fully understanding the malocclusion causes,orthodontists should select, improve, or design a more fast, effective, safe, and comfortable method according to specific circumstances. This paper provides an overview of posterior crossbite about etiology, clinical harm, the shortcomings of traditional clinical treatment methods, principles of improvement or design, and the prevention and treatment of possible problems in the process. And the application of three improved new appliances is introduced, which will provide reference for clinical practical treatment of posterior crossbite.

Key words: Posterior crossbite, Practicability, Innovation