Objective To investigate the effect of unilateral mastication on glenoid fossae bymeans of animal experiment. Methods An animal model of unilateral mastication was established by extracting right mandibular molars of Wistar rats. The rats were sacrificed in different period to examine the location changes of glenoid fossae through sagittal and horizontal plane.Re- sults The anterior points of glenoid fossae in non-masticatory side of experimental groupswere more anterior than those in masti- catory sides. The anterior points of the glenoid fossae of non-masticatory sides in experimental groupswere more anteriorthan those of the same sides in the control groups after inducing unilateral mastication fortwo and fourmonths. After inducing unilateral mas- tication for two and fourmonths, the anterior and the posterior points of the glenoid fossae of non-masticatory sides in experimental groups became closer to the midline by comparisonwith masticatory sides aswell as the same sides in control groups. Locations of glenoid fossae in masticatory sides showed no changes in comparison with the same side of the control groups.Conclusion The forward and inward remodeling of the glenoid fassae can be observed after unilateral mastication was induce to the non-masticatory sides of experimental rats. It is concluded that unilateral mastication might be one of the etiologic factor of temporomandibular joint disorders.
