profile and soft tissue changes during and after orthodontic treatment

Abstract

A study was made of the relationship between changes in dentofacial or alveolar structures and soft tissue profile in 113 successfully treated orthodontic patients. Linear and angular measurements were made of lateral skull radiographs and profile photographs of 90 Class II Division 1 cases and 23 Class III cases. Similar measurements were carried out on records of 17 non-treated male patients who served as a control. There was a considerable change in soft tissue profile in all the groups studied, primarily due to nasal growth and forward growth of the soft tissue chin. The changes in lip position resulting from orthodontic treatment were relatively insignificant. Muscle tonicity has a considerable influence on lip form and position and it is difficult to predict changes that would occur in the lip but, generally, variation in lip position occurred only when supporting alveolar bone and tooth position changed beyond a certain level.