Magnetic resonance sialography in bilateral Stafne bone cavities

International audienceStafne bone cavities (SBC) are mandibular radiolucent lesions with challenging differential diagnoses. Many radiological methods have been proposed to demonstrate the presence of salivary gland tissues inside the cavities

A partial 45 MHz sky temperature map obtained from the observations of five ST radars

A sky temperature map at 45 MHz covering declination between + 30° and + 60°&nbsp; is presented. The sampling in right ascension is 20 min (~5°) and 2°&nbsp; in declination in most of the map. The originality of the work was to use cosmic emission measurements from five VHF Stratosphere-Troposphere (ST) radars collected during long periods of routine meteorological surveys. This map, which has an accuracy in temperature of about 600 K, is intended first for radar reflectivity calibration and system performance monitoring. The presence of two strong radio sources, Cassiopeia A and Cygnus A, can also serve as the verification of the beam diagram, beam width, and beam pointing direction of the antenna. Finally, this work is an attempt to show the potentiality of ST radar for astronomical purposes.<br><br><b>Key words. </b>Meteorology and atmospheric dynamics (instruments and techniques) – Radio science (radio astronomy

Mechanical behaviour of a membrane made of human umbilical cord for dental bone regenerative medicine

International audienceGuided bone regeneration (GBR) is one of the most attractive techniques for restoring oral bone defects following tooth extraction or periodontal disease. To ensure the stability of a dental implant, the GBR technique relies on the use of an occlusive membrane, which is positioned as a barrier over the bone defect, providing space maintenance required for bone growth and preventing the ingrowth of fibrous tissue into the bone defect (Elgali et al. 2017). This membrane has to meet criteria guidelines in terms of mechanical properties, as the membrane has to allow a good handling for dental surgeons, without collapsing into the bone defect. Healthy perinatal tissues are promising biomaterials because they are inexpensive, and universally available (Ferguson and Dodson 2009). Among these tissues, the human umbilical cord, mainly composed of collagen fibres and glycosaminoglycan, especially hyaluronic acid and chondroitin sulphate, is expected to offer outstanding opportunities for tissue engineering by serving as a suitable biocompatible membrane for GBR.In this study, a novel membrane derived from the human umbilical cord (UC-membrane) was successfully developed following tissue stripping and freeze-drying processes. Ice crystal formation following tissue freezing is known to induce pore formation within the tissue, hampering their mechanical properties. Herein, the mechanical behaviour of UC-membrane was determined and compared to the Bio-Gide® membrane (gold standard membrane

Haemostatic sponges as an alternative to granular bone substitute for sinus lifts

International audienceInsufficient residual alveolar bone height is a common obstacle for the placement of dental implants in the posterior maxilla. Sinus lifting procedure involves the creation of a sub-sinus membrane pocket and the grafting with granular bone substitutes. Perforation of the sinus membrane is the most common complication with a large incidence rate (Testori et al. 2019). Graft material leak, through the perforation, results in a dental implant failure and/or postoperative sinusitis, requiring a complete reviewing of the maxillary sinus cavity and the removal of the remaining bone graft. The high perforation rate has led to develop new options involving 3 D biodegradable scaffolds instead of using granular bone substitutes. Case reports and case series have pointed out successful new bone formation after sinus membrane elevation using reoxidised cellulose (Gray et al. 2001), venous blood clot (Moon et al. 2011) and gelatin sponge (Sohn et al. 2010) as space maintainers. The main limitation of this promising technique was that the sub membrane space volume was limited and hardly predictable. The aim of this study was to evaluate the mechanical behaviour and volume kinematics of several haemostatic sponges to find out the best haemostatic medical device as space maintainers for new bone formation in sinus lift surgery. This study has been focused only on two devices: Gelita-spon® and Hemocollagene®. It aims to compare substitutes respectively made of porcine gelatine and bovine collagen