[The histologic study on chronological changes of bone trabeclae in human postnatal mandible]

The histologic study on chronological changes of human mandible was performed using 35 postnatal cases. The changes of bone density were divided into following 2 stages. In cases of a 11 hours new born to 2 months (No. 13) baby, the bone density consisted of rather moderate parts that low. In cases of 2 months (No. 14) baby to 66 years adult, it consisted of rather low parts than moderate parts. The changes of bone maturation were divided into next 2 stages. In cases of a 11 hours new born to 3 months baby, the mandible consisted of woven-lamellar or lamellar bone. In cases of after 7 months baby to 66 years adult, it only consisted of lamellar bone. And then, the mandibular bone were exhibited manifold arrangements. The reticular arrangements were appeared locally in cases of a 11 hours new born to 2 months baby but after 3 months, these were disappeared. The oblique and horizontal arrangements were appeared mainly in cases of a 11 hours new born to 7 months baby, and after 1 years old, not only these arrangements but also islet-like and vertical arrangements were appeared partially. After 40 years old, islet like arrangements were appeared remarkably. The bone resorption was noted at the whole mandible in a case of 3 months, and it extended larger in a case of 7 months. And after 1.1 years old, it was noted as same as 7 months.