An experimental study on mandibular movement and osteoporosis.

In order to clarify the relationship between mandibular movement and osteoporosis, the authors secured the temporo-mandibular joints of 8-week-old rats to immobilize their jaws; then conducted histologic studies chronologically, up to the fifth week. After three weeks, an expansion of the marrow cavity and a reduction of the trabecular were observed in the mandibular process and mandibular fossa. During the fifth week, an osteoporosis-like state was clearly observed. Further, an irregularity in the form of mandibular process was recognized, as well as a remarkable disturbance caused by cartilaginous ossification of the articular cartilage of the condyle.