[Establishment of an animal model of widening distraction of tubular bone with dental implant distractor].

OBJECTIVE

To establish an animal model of widening distraction of tubular bone with dental implant distractor (DID) and investigate radiographical and histomorphological changes of long tubular bone following widening distraction with dental implant.

METHODS

Twelve Chinese mountain goats were used. Two sets of DID were installed in each goat's tibiae. After an 8-day latency period, nine tibiae were distracted at a rate of 0.35 mm each time and 2 times per day using DID devices. Radiography and histomorphology were used to evaluate the new generated bone in different period after distraction. The other three animals served as sham control.

RESULTS

After 10 - 14 days' distraction, the average width of the tibiae increased by 7.83 mm. Digital subtraction angiography (DSA) showed that there was a similarity between goat's tibiae and human's fibula in the blood supply. From the end of distraction to 3-month after the consolidation period, radiography demonstrated that the distraction gaps gradually became vague and filled with newly formed bone. The histomorphological study showed different results of bone formation in both distracted gaps. The osseointegration between bone and implant only occurred at screw-shaped part, while the moving part in tibiae was encapsulated by fibrous tissue.

CONCLUSIONS

There are lots of similarities between goat's tibiae and human's fibula in anatomy and blood supply. The model of widening distraction osteogenesis of the goat's tibiae is ideal for studying human's fibula.