A full face motorcycle helmet and an open face motorcycle helmet (also known as a 3/4 motorcycle helmet) offer greater coverage than a short or half motorcycle helmet.
Look for a helmet that provides not only a significant amount of shell surface area coverage, but also coverage from the inside EPS (Styrofoam-like liner). It is the EPS liner that absorbs impact energy. While some motorcycle helmet manufacturers cover a minimum mandated area with EPS, others line the entire shell. Helmets with chinbars should have an extended area of EPS liner.
Between full face helmets and open face helmets, motorcycle helmets with flip-up facial sections known as "modular," "system" or flip-face helmets offer comfort and convenience as well as good coverage.