Model to assess duration of distraction compared with degree of incisal crowding in symphyseal distraction osteogenesis

Abstract Our aim was to evaluate symphyseal distraction in relation to duration of expansion, and to propose an optimised procedure. Eighteen patients (mean (SD) age 19 (7) years) with transverse mandibular deficiency were treated by symphyseal distraction osteogenesis. The mean (SD) anterior dental crowding measured was 6.8 (4.2) mm. We retrospectively compared the width of expansion between the canines (ICE) and expansion between the first molars (IFME) after symphyseal distraction according to the distraction time. The median (range) duration of expansion was 13.6 (7–21) days. The median (range) ICE distraction width was 5.5 (3.4–8) mm and IFME width 3.3 (1–7.9) mm ( p p 2 .