A careful review of the literature reveals an absence of studies about the reactions of dental
pulp to orthodontic extrusion. The purpose of the present research investigation is to study
the pulpal reactions and the sequence of histologic events in human dental pulp after
orthodontic extrusion. The sample consisted of 36 intact maxillary first premolars of young
adult orthodontic subjects. The mean age of the subjects was 18 years. Eighteen maxillary
first premolars were extruded, under controlled conditions with the aid of fixed edgewise …