1) Background: The present study was performed to compare histopathologically between two different fixation techniques after surgically induced unilateral subcondylar fracture in dog TMJ; 2) Methods: Twenty- One healthy beagle male dogs with a mean age of thirty months were included in this study. One of these animals was sacrificed to study the normal histology of the dog TMJ. The rest of the animals (Twenty animals) were operated on to induce a displaced unilateral subcondylar fracture then, the animals were randomly equally divided into two groups, group I (MMF group), and group II (plate fixation group). After surgery, five dogs of each group were sacrificed at two months after surgery, while the remaining five dogs were sacrificed at four months after surgery. After termination of the experiment, the entire TMJ was removed, decalcified, washed, and sectioned in a sagittal plane. Tissue sections of 4 um thick were cut and stained with H & E to be studied microscopically; 3) Results: There was a highly significant difference in the total thickness of the articular fibrous covering of condylar head between the two groups at the different periods, meanwhile, there was no significant difference in the thickness of condylar cartilage, in group II, no significant changes could be detected either in thickness or structure of the articular fibrous covering when compared to normal; 4) Conclusion: Results of the present study suggest that plate fixation could give the most favorable results, when compared with MMF group

Subcondylar fracture; Histopathologic study; TMJ; MMF; Miniplate fixation