i have a 10 month old airedale. at what age do they physically mature? his head seems small for his body, does it mature later?

I love Airedales! They are slow maturing (especially mentally!!!!). The head is supposed to be fairly long & narrow with flattish cheeks. It's the coat that makes all the difference, particularly the whiskers on his muzzle. You can make him look totally different with clever trimming, but unless you are showing him, why bother? He's still the same dog underneath. His head will broaden with age, particularly as his jaw muscles develop, but an Airedale with a large head isn't desirable anyway. Enjoy him as a youngster, he'll grow up too quickly as it is.