Three-dimensional assessment of treatment outcomes on the face.

OBJECTIVES: To investigate the effect on the face of treatment involving extractions. DESIGN: A prospective study of the effects of extraction and non-extraction treatment on two groups of patients was undertaken. SETTING AND SAMPLE POPULATION: Initially there were 16 non-extraction and 18 extraction patients but at the end of treatment there were only 12 in each group. EXPERIMENTAL VARIABLE: Each of the patients was scanned using a three-dimensional (3-D) MGI scanner and the 3-D scans were analysed using registration and surface shape analysis programs. The registration program registers the scans over the forehead and then shows the differences in colour between the two scans. The surface shape analysis mathematically differentiates the surface into nine different surface shapes. RESULTS: The results indicated that there was a difference between the two groups at the start of treatment but there were no differences in the effect on the face of treatment in the two groups. The surface morphology was similar at the end of treatment in both groups. CONCLUSION: It was concluded that in this preliminary study that whether treatment is undertaken with or without extractions, in this group of patients the facial morphology was not significantly different.

The three-dimensional effects of orthodontic treatment on the facial soft tissues--a preliminary study.

OBJECTIVE: To examine the three-dimensional effects of extraction and non-extraction orthodontic treatment on the facial soft tissues. SETTING: Department of Orthodontics, Royal London Hospital. DESIGN: Longitudinal study of two prospective cohorts of patients who were attending for orthodontic treatment. METHOD 12 patients were included in each group, in accordance with the selection criteria. Three-dimensional optical surface scans of these patients were obtained in the one month prior to having fixed appliances placed and this was repeated at the end of treatment. RESULTS: The average face of the non-extraction patients was of greater general dimensions than the extraction average, both at the start and the end of treatment. During the fixed appliance treatment, the vermilion of the upper lip became more protrusive to a similar extent in both groups in relation to the reference plane. The lower lip vermilion and the philtrum showed no change for either group over the treatment time. The labiomental fold area showed a slightly greater forward movement in the extraction group with treatment. CONCLUSION: Three-dimensional optical surface scanning allows data from the whole of the face to be assessed, as opposed to the lateral profile view used in the majority of the studies to date. The effects of the two types of treatment on the facial soft tissues were very similar, indicating that orthodontic treatment involving the extraction of teeth does not have a detrimental effect on the face.