The present study was designed to compare the resultant bone healing of bicortical compression osteosynthesis with that of monocortical noncompression osteosynthesis.
In order to carry out this experiment, 4 Korean dogs weighting about 12 Kg were selected. In order to make a fracture with minimal bone defect between fragments and without compound fracture into the oral cavity and damage of the inferior alveolar nerve and vessels, the both sides of mandibular body region between the 4th bicupid and the 1st molar were fractured by making V-shaped groove and 4 holes, and manipulating a lever.
At the left side,, fractured site were fixed with autocompression plate and screws and in the right side, fixation was performed with two_ miniplates and screws.
Experimental dogs were sacrificed at 4th and 6th week after surgery and the soft tissue were dissected from the mandible.
The fracture site was observed grossly and examined under the light macroscopeto observe the bony repair process histopathologicalIy.
The results obtained from this study were as follows ;
1. All fractured sites appeared macroscopically to be healed well and any interfragmental morbilitycouldn´t be felt at all.
2. Both groups showed external callus. Especially, large excrescences of external callus which were most extensive at the inferior border of the mandible were showed in the group used with miniplate.
3. At 4th week, the group used with compression plate showed bone repair process with new bone formation from theperiosteum in the periphery of the fractured fragments and fibrous callus in the inner side of the gap between the fractured fragments, and at 6th week, the fractured site was almostly healed with new bone with distinct reversal line.
4. At 4th week, the group used withnoncompressive miniplate showed bone repair process with newly-formed connective tissue containing scattered, new bone formation, and at 6th week, bony healing was started from the periphery of the fractured fragments.
5. The group used with compression plate showed better repair process than the group used with noncompressive miniplate.
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