An experimental model reproducing open bite or verticalized facial pattern was used to study its effect on the temporomandibular joints. 140 Wistar rats were used, divided into 3 groups: bilateral resection of the masseteric muscle, simulated muscular resection and control group. A series of radiological, morphological and histological tests were analyzed. The posterior rotation of the jaw caused by muscular resection although not producing a degenerative effect, did produce specific articular changes in the temporomandibular joint components.