Microangiography of the rabbit temporomandibular joint in the open and closed jaw positions

The purpose of this investigation was to test the hypothesis that jaw position significantly affects the vascular morphology of the temporomandibular joint (TMJ). The study was performed using intravascular perfusion with 30% Micropaque and 40% gelatin. Six anesthetized New Zealand white rabbits were divided into 2 groups of three. Group 1 rabbits were perfused in the resting, closed-jaw position and group 2 rabbits were perfused while the jaw was held open. The animals were killed with an overdose of pentobarbital and frozen. The heads were hemisected, fixed, decalcified, and embedded in Cedukol. Sagittal sections were cut at the level of the meniscus and radiographed with a specimen x-ray unit on high-resolution film. The 6 rabbits (12 TMJs) demonstrated consistent microvascular differences. In 83% of the jaws in group 2 rabbits the anterior condylar vein was not seen or appeared patchy whereas the same vein was readily seen in all jaws of group 1 ( P < .01). The superior condylar vasculature was distended in 83.3% of group 2 jaws and in 16.7% of group 1 jaws ( P < .05). This study demonstrates significant changes in vascular morphology when the jaw is placed in the open position.