Protraktion

Protraktion, often translated as protraction, is a term used in anatomy, physiology, and related medical fields to describe the forward movement or projection of a body part away from the midline or trunk. It is the opposite of retraction, which denotes posterior movement.

In human anatomy, protraction refers to anterior translation of a segment. Common examples include scapular protraction, where the shoulder blades move forward on the rib cage, and mandibular (jaw) protraction, where the lower jaw is pushed forward. These movements are involved in actions such as reaching, pushing, and chewing, and they are described in clinical assessments and physical therapy.

In dentistry and orthodontics, protrusion describes forward positioning of teeth or the entire dental arch relative to the jaws. Incisor protrusion can affect bite function, lip closure, and facial profile. Clinically, protrusion is evaluated by measures of tooth inclination and overjet. Treatment considerations may involve orthodontic appliances, functional devices, or, in severe cases, surgical correction to improve alignment and facial aesthetics.

Other uses of the term appear in biomechanics and comparative anatomy, where protraction denotes forward movement of a limb segment during locomotion or a forward projection of anatomical structures in various species. Across disciplines, the concept is consistently defined as forward displacement or projection, with retraction serving as its directional opposite.