Perioral soft-tissues in orthodontics

Abstract

The effect of orthodontic extractions on the face has been a contentious issue in orthodontics for over a century. The soft-tissue properties of the lips have often been cited as a factor affecting the facial response to orthodontic tooth movement. The first part of this project was an observational study using a hand-held myotonometric device to measure the soft-tissue properties of the lips, and found variability between age, sex, BMI, anatomic site, lip morphology, and craniofacial morphology. The second part was a pilot study that successfully designed a non-invasive, retrospective method to investigate the three-dimensional response of the soft tissues to incisor retraction. Despite marked interindividual variation among the small sample, the lip retraction was consistently less than the amount of incisor retraction.