Influence of facial growth pattern on outcome of extraction therapy

The present clinical-radiological study analyzes orthodontic casts and lateral cephalometric X-rays (at start and finish of orthodontic treatment) of 56 extraction cases, most of them adolescent patients who had 4 teeth extracted. The test group was classified into 3 morphological categories according to growth patterns. For comparison purposes, cephalometric findings of morphologically matching non-extraction groups as well as corresponding data from the literature were used. There was no deepening of overbite in any of the extraction cases in the different test groups. However, an average bite opening of 1.2 mm was found in patients with a neutral or horizontal growth pattern. Irrespective of the growth pattern, a significant increase in anterior and posterior facial height as well as a mean reduction of the ANB angle between 0.9 degrees and 1.3 degrees was found in the different extraction groups. These results matched those of the corresponding nonextraction control groups. At the end of treatment, the longitudinal axis of the upper incisors appeared too steep (retruded). Overall, the individual growth pattern was found to be of very little relevance to treatment results, provided a well considered treatment plan had been drawn up.