Dentoskeletal Changes Concomitant With Different Three Levels of Force Application for Maxillary Protraction in Growing Orthodontic Patients With Class 3 Malocclusion

Nanda reported that numerous experimental studies on primates have shown orthopedic changes in response to extraoral forces; however, very few studies have made an attempt to analyze the different force variables and their relationship to facial sutures. In consideration of the variables, experimental and clinical studies were initiated in their laboratory in 1972. A study on protraction of midfacial bones on primates reported that the point of force application significantly influences the center of rotation of the maxilla in rhesus monkeys. Our unpublished data also show that centers of rotation are influenced by the magnitude of force. The study showed that the maxilla can be successfully protracted by means of carefully controlled forces.

Based on the aforementioned data, we can hypothesize that the point of force application for maxillary protraction in relation to the center of resistance of maxilla could be utilized in order to correct skeletal class 3 malocclusions with different vertical dimension discrepancies.