Evaluation of a semiburied, fixed-trajectory, curvilinear, distraction device in an animal model

Purpose: This study evaluated a new small, buried distracter, capable of cu rvilinear movement while following a fixed trajectory. The geometrical basi s for such devices and the 3-dimensional treatment planning system required to make buried distracters practical are discussed. Materials and Methods: A curved rack and worm-gear device, based on the des ign of a hose clamp, was constructed to produce a curved distraction path, and this distractor was tested in 2 minipigs using a protocol with zero lat ency and 1 mm/d X 7 days of distraction. Serial standardized lateral cephal ograms were used to verify distracter function and path. Results: Curvilinear distraction was documented by clinical examination and serial cephalometric analysis in the 2 minipigs. Observed angulation of th e margins of the wedge-shaped distraction gap conformed to the calculated a ngulation based an the fixed radius of curvature of the distracter. Conclusion: Distraction along a curved trajectory using a small, semiburied , curvilinear device of novel design is feasible in the minipig mandible.