Orthodontic tooth movement and distraction osteogenesis

The purpose of this preliminary study was to compare the rate of orthodontic tooth movement into bone regenerate created after mandibular DO with the rate of orthodontic tooth movement in patients in which extraction was performed and followed by traditional orthodontic treatment. The rate of orthodontic tooth movement into bone regenerate created after mandibular DO in 14 Class II subjects (5 males and 9 females, mean age 25.0 +/- 1.1 years) treated with Distraction Osteogenesis appliance was compared with the rate of orthodontic tooth movement in 20 subjects (mean age 19.9 +/- 3.8 years), in which extraction was performed and followed by traditional orthodontic treatment for space closure. Teeth movements (amount and rate) were evaluated by measuring the distance between the distal wing of the canine and the mesial wing of the first premolar bracket with Vernier callipers (Dentaurum). Readings were noted every 2 weeks until space closure was completed. In the present study the mean duration of the Post-distraction orthodontic treatment (orthodontic tooth movements, finishing) was 10 +/- .5 months. The mandibular posterior teeth were moved into the edentulous segment created by distraction using active tieback in 8 +/- 1 months; the average time to complete space closure was 3.34 +/- .94 months in the traditional orthodontic treatment. The average space closure was 4.24 +/- 1.32 mm in the traditional orthodontic treatment and 5.46 +/- 0.35 mm in the patients treated with DO. The mean rate of tooth movement was 1.27 +/- 0.23 mm/month in the in the traditional orthodontic treatment and 0.68 +/- 0.20 mm/month in the in the patients treated with DO (Table I). Unpaired t test showed a significant difference between tooth movement in the study sample and in the control group (p>.05). As suggested by most scientific literature, in our sample, dental movement was started at the end of the latency and consolidation time. However, the amount and rate of space closure in the distraction area were higher than with traditional orthodontic treatment. In conclusion, the purpose of this study was to highlight the need for careful assessment of working time on patients undergoing distraction osteogenesis. Undoubtedly, this approach can be used for treatment of very severe skeletal malocclusions and maxillofacial deformities, but it cannot be considered an alternative to traditional orthodontic surgery to speed up treatment since the process of tooth movement requires its time.