Effects of rapid distraction rate on new bone formation during mandibular distraction osteogenesis in goats

Objective

Distraction osteogenesis typically requires a long treatment period, which can lead to bone and soft-tissue infection and considerable patient discomfort. Use of a rapid distraction rate in craniofacial distraction osteogenesis to shorten the distraction period is possible owing to the unique characteristics of craniofacial bones, including an abundant blood supply and rapid bone healing compared with long bones. The effects of using a rapid distraction rate in the treatment of craniofacial deformities are currently unclear, however. The objective of this study was to investigate the effects of a rapid distraction rate on new bone formation during mandibular distraction osteogenesis in goats.

Methods

Sixteen goats were randomly divided into four groups consisting of four goats each. In Groups A, B, and C, the right mandible of each goat was distracted at a rate of 0.8 mm/d, 1.6 mm/d, and 2.0 mm/d, respectively; Group D was the control group and did not undergo distraction. Six weeks after the conclusion of distraction, bone densitometry and three-point bending testing were performed in all groups.

Results

The mean bone density value of goats in Group A was significantly higher than those of all the other groups (p < 0.05), and the mean bone density value of goats in Group C was significantly lower than those of all the other groups (p < 0.05). The mean curve slope, peak stress, bending modulus, and energy to failure values of Groups A, B, and C were all significantly lower than those of the control group (p < 0.05). As the distraction rate increased, the curve slope and peak stress values gradually declined (p < 0.05).

Conclusions

Use of a rapid distraction rate in mandibular distraction osteogenesis may have detrimental effects on the quality of new bone, despite the abundant blood supply of craniofacial bones.