Search

Osteonecrosis of the jaw induced by administration of bisphosphonates (BPs), BP-related osteonecrosis (BRONJ), typically develops after tooth extraction and is medically challenging. As BPs inhibit oral mucosal cell growth, we hypothesized that suppression of the wound healing-inhibiting effects could prevent BRONJ onset after tooth extraction. Since basic fibroblast growth factor (bFGF) promotes wound healing, but has a short half-life, we examined whether the initiation of BRONJ could be prevented by applying a bFGF-containing gelatin hydrogel over the extraction sockets of BRONJ model rats. Forty-three rats, received two intravenous injections of zoledronic acid 60 μg/kg, once per week for a period of 2 weeks, underwent extraction of a unilateral lower first molar. The rats here were randomly assigned to the bFGF group (n = 15 rats, gelatin hydrogel sheets with incorporated bFGF applied over the sockets); the phosphate-buffered saline (PBS) group (n = 14 rats, gelatin hydrogel sheets without bFGF applied over the sockets); or the control group (n = 14 rats, nothing applied over the sockets). One rat in the bFGF group was sacrificed immediately after tooth extraction. Twenty-one rats were sacrificed at 3 weeks, and the remaining 21 rats were sacrificed at 8 weeks after tooth extractions. The harvested mandibles were analyzed using micro-computed tomography and sections were evaluated qualitatively for mucosal disruption and osteonecrosis. The incidence of osteonecrosis at 8 weeks after tooth extraction was 0% in the bFGF group, 100% in the PBS group, and 85.7% in the control group. The frequency of complete coverage of the extraction socket by mucosal tissue was significantly greater in the bFGF group than in the other groups. These results suggest that application of bFGF in the extraction socket promoted socket healing, which prevented BRONJ development. The growth-stimulating effects of bFGF may have offset the inhibition of wound healing by BP.

Maxillofacial fractures of pedestrians injured in a motor vehicle accident were retrospectively analyzed. The patients were 38 males and 26 females, and their age was distributed almost evenly from 1 to 91 years old (average 45.9 ± 24.8 years old). Motor vehicle collisions were with an automobile in 46 patients (71.9%), a motorcycle in 17 (26.6%), and a train in 1 (1.6%). The midface was involved in 32 patients (50.0%), the mandible in 19 (29.7%), and both the mandible and the midface in 13 (20.3%). Fractures were frequently observed in the zygoma and alveolus in the midface and in the condyle, symphysis, and body in the mandible. The facial injury severity scale (FISS) rating ranged from 1 to 9 (average 2.30 ± 1.79). Injuries to other sites of the body occurred in 29 patients (45.3%). Observation was most frequently chosen in 26 patients (40.6%), followed by open reduction and internal fixation (ORIF) in 18 (28.1%), and maxillomandibular fixation (MMF) in 8 (12.5%). The FISS rating was higher in patients treated with ORIF and MMF. Injuries to other sites of the body were observed at a higher rate in patients who collided with an automobile and were also treated by ORIF.

ObjectiveThe effect of direct oral anticoagulants (DOACs) on the risk of bleeding after tooth extraction remains unclear. This study aimed to evaluate the incidence of postextraction bleeding among patients who received DOAC and vitamin K antagonists (VKAs), such as warfarin.DesignThis study was a retrospective cohort analysis. Incidence rates and propensity score-matched regression models were used to compare the risks of bleeding after tooth extractions involving DOACs and VKAs.SettingThe study took place in a single university hospital in Japan.ParticipantsBetween April 2013 and April 2015, 543 patients underwent a total of 1196 simple tooth extractions.Primary outcome measureThe primary outcome measure was the occurrence of postextraction bleeding, which was defined as bleeding that could not be stopped by biting down on gauze and required medical treatment between 30 min and 7 days after the extraction.ResultsA total of 1196 tooth extractions (634 procedures) in 541 patients fulfilled the study criteria, with 72 extractions (41 procedures) involving DOACs, 100 extractions (50 procedures) involving VKAs and 1024 extractions (543 procedures) involving no anticoagulants. The incidences of postextraction bleeding per tooth for the DOAC, VKA and no anticoagulant extractions were 10.4%, 12.0% and 0.9%, respectively. The incidences of postextraction bleeding per procedure for DOACs, VKAs and no anticoagulants were 9.7%, 10.0% and 1.1%, respectively. In comparison to the VKA extractions, the DOAC extractions did not significantly increase the risk of postextraction bleeding (OR 0.69, 95% CIs 0.24 to 1.97; p=0.49).ConclusionsThe risk of postextraction bleeding was similar for DOAC and VKA extractions.

The development of Superconducting Electro-Magnetic Propulsion Ship has been going on, featuring a new propulsion concept that has never been actually applied to any ship before. The propulsion of the ship is performed by the thrust force with the use of superconducting electo magnetic thruster instead of the conventional system.Initiated by Ship & Ocean Foundation (old name: Japan Foundation for Shipbuilding Advancement) in 1985, the research and development have been continued on superconducting magnet, electrode, liquil helium refrigerator, hull form, etc. The study is now coming to the final stage, followed by the sea trial expected in next year.In this paper, the result of the study and design concept of the said experimental ship is focussed on the propulsion system as to the feature of the propulsion plant.