Continuous versus discontinuous distraction: evaluation of bone regenerate following various rhythms of distraction

To investigate continuous distraction osteogenesis (DO) of the nasal bones in a rabbit model, and to compare data from this continuous DO study with data from a previously conducted discontinuous DO study. In addition, radiographic and ultrasonographic bone-fill scores were determined to investigate whether these scores provided reliable predictive value for the amount of new bone formation in the distraction area.

Skeletally mature female New Zealand White rabbits were subjected to distraction of the nasal bones. A custom-made continuous distractor was used to perform automatic non-stop distraction. Bone data were obtained from radiography, ultrasonography, and microcomputed tomography. Data from this experiment were compared with data from a previous study on discontinuous distraction rhythms.

Ultrasonographic bone-fill scores correlated significantly to actual bone volume in contrast to radiographic bone-fill scores. Bone volume was significantly higher in the continuous DO group compared with the discontinuous DO groups.

Continuous distraction resulted in accelerated osteogenesis compared with discontinuous distraction. Furthermore, bone-fill scores based on ultrasonography showed a significant correlation with actual bone volumes.