Abstract:

Objective

To discuss the possibility of bone formation by periosteum to restore the mandibular defection of minipig and the critical length of the discontinuous defection.

Methods

Ten female 18-month-old minipigs were used in the study. The premolars and the first molar in the right mandible of each minipig were extracted. Two months later， the animals were divided into two groups randomly， six in Group 1 and four in Group 2. In Group 1， mandibular defects measuring 40， 50 and 60 mm long were created preserving the periosteum； In Group 2， mandibular defects measuring 10 mm and 20 mm long were created without preserving periosteum. Two minipigs for each defection length. The mandibles were then stabilized with rigid internal fixation. X-ray photographs were taken 4， 8 and 12 weeks after operation.

Results

X-ray photographs of 12 weeks after operation showed that all the mandibular defection were restored with new calcified bone in the 40， 50 and 10 mm subgroups， while the mandibular defection cannot be restored in the 60 mm and 20 mm subgroups.

Conclusions

Bone forming by periosteum is a new method to rehabilitate the mandibular discontinuous defection of minipig shorter than 50 mm.

Key words: Minipig, Mandibular defection, Bone formation by periosteum