Osteoradionecrosis of the jaw (ORNJ) and bisphosphonate-related osteonecrosis of the jaw (BRONJ) are usually caused by head and neck radio-therapy and by the usage of bisphosphonate, respectively. These diseases can lead to facial deformity and dysfunction of the mandible, and may cause severe chronic facial pain. The pathogenesis of ORNJ and BRONJ are complex, and the therapy of which is still challenged. The present article reviewed the latest literature about the pathogenesis and treatment of ORNJ and BRONJ for update. The irradiation may damage the endothelia cells and microvessels in jaw bone, which leads to the termination of the bone remodeling 15 days after irradiation. Mesenchymal stem cells based bio-therapy can assist the recovery of mandibular circulation and the reconstruction of the bone, showing therapeutic potential for ORNJ clinical treatment. Bisphosphonate can induce the dysfunction of bone marrow mesenchymal stem cells and the immune imbalance of the body. Allogeneic mesenchymal stem cells transplantation can rebuild the jaw bone and rebalance the immune of the recipient, demonstrating the ideally potential for the treatment of BRONJ. Taking together, although it would be complicated and winding, the improvement of biotech and the usage of mesenchymal stem cells shed a light on the way of ORNJ and BRONJ treatments.

Objective To observe prenatal ultrasonic manifestations of fetal rhomboencephalosynapsis(RES).Methods Data of 15 singletons with RES were retrospectively analyzed,and the prenatal intracranial and extracranial ultrasonic manifestations were observed.Results All 15 fetuses were found with transverse cerebellar diameter lower than the 3rd percentile of normal value in the same gestational week and bilateral cerebellar hemisphere fusion(15/15,100％).Cerebellar vermis completely loss was observed in 14 fetuses(14/15,93.33％),while partially loss was noticed in 1 fetus(1/15,6.67％).Invisible of the fourth cerebral ventricle was detected in 4 fetuses(4/15,26.67％),while the fourth cerebral ventricular index(4Vi)＜1 was found in 11 fetuses(11/15,73.33％).No"split line"sign between vermis and cerebellar hemisphere was detected.A total of 14(14/15,93.33％)were found with combining intracranial or extracranial malformations,including 13(13/14,92.86％)with other intracranial malformations,10(10/14,71.43％)with extracranial malformations,whereas 1(1/15,6.67％)fetus had no other malformation.Conclusion Prenatal ultrasonic manifestations of fetal RES mainly included small cerebellum transverse diameter,complete or partial loss of vermis,invisible or dysplasia of the fourth cerebral ventricle,fusion of bilateral cerebellar hemispheres,as well as combining with other intracranial and extracranial malformations.