This is an analysis from Germany where they reviewed over 7000 bicycle accidents over a 16-year period that met their inclusion criteria. Over 1000 had a facial injury (bone or soft tissue) with helmets being worn in 11.8% of accidents. They acknowledge factors such as incorrect sizing or wearing of the helmet, and the possibility of coincidence bias in their analysis. Nonetheless, they conclude there is no protective effect of a standard bicycle helmet with regard to facial injuries following an accident. They suggest methods of better acceptance so that a helmet may be worn and extending it further down to protect the upper face.
