this class is currently a union of the snout (e.g. in mouse), the midface and the lower face. Note that in MA, snout includes the whole jaw and should thus be more alike the lower face than the midface, so its placement here is not strictly accurate. In future we might introduce specific classes for each of these, and include the full parthood relationships. if this is done, then care should be taken to preserve inferences such as an abnormality of the lower face being an abnormality of the midface.