Analysis of the performance of different orthodontic devices for mandibular symphyseal distraction osteogenesis

摘要

The aim of this study was to investigate the performance of different orthodontic devices for mandibular symphyseal distraction osteogenesis (MSDO). Two performance parameters were analysed, the first of which concerned the stability guaranteed by a distractor in the fracture gap under mastication loads and the second the level of reliability with which a distractor transfers a given expansion to the mandibular bone, inasmuch as the more reliable the device the smaller the difference between the degree of expansion provided to the device and the displacement achieved on the mandibular arch. Hence, a non-linear finite element (FE) model of a human mandible with different devices (tooth-borne, bone-borne, and hybrid) was constructed and then utilized to assess the structural behaviour of the mandibular bone under distraction and mastication loads. An ad hoc algorithm was developed to simulate progressive expansion of the devices; a distraction protocol comprising a 10 day latency period and a 6 day distraction period was hypothesized. The first hypothetical expansion given to the device was 2 mm, and the five subsequent expansions were 1 mm.