[Current situation of clinical research on impacted premolars].

Teeth impaction is a common developmental malformation in oral diseases. Impacted teeth are usually the canines, third molar, central incisors, premolars, and second molars. The prevalence of impaction of maxillary canines and mandibular wisdom teeth is higher than that of other teeth. Most recent studies have focused on the canines and third molars, but research on impacted premolars is limited. In clinical practice, the majority of orthodontic patients require premolar extraction. Thus, impacted premolars play important roles in orthodontic design and prognosis. This article provides an overview of recent research on impacted premolars and summarizes epidemiological features, localizations, and treatments, with the aim of guiding practitioners on orthodontic design and therapy.