I've emailed Mommaerts and have received similar abrupt replies to surgery questions.
I put it down to the fact that he's an extremely busy man, and when he gets emailed questions from patients, I understand if he just wants to fire off the replies quickly and efficiently.
When he emailed me, he had just arrived at an airport and in the following email he was courteous enough.
I found him to be very nice when I met him for a consultation.
For balance I should give my experience too.
Herr B?ttner is an incredibly helpful man, and is also a surgeon who works with MM (I think).
Through Herr B?ttner I was able to organise skype consultations free of charge, which easily lasted 30 minutes of him answering all my questions in detail. Mind you did this after he had finished an operation, so that's pretty special imo.
Overally my consultation with him in person was great, and the follow-ups were also reassuring. I did have problems with the English receptionist who disappeared for medical reasons, however since switching to the German doctor I've received much better service.
I can't really tell you why some people might find him dismissive. Could it be he just isn't good with e-mail, and a lot of this is happening over e-mail? Does he just not like British people? Perhaps he just likes Germans / Francophones such as myself?
Either way I can't knock them for service so far. Especially when all the other maxfac surgeons I've contacted just seem to disappear once I've had my consult. Dr Alfaro and another in Holland were particularly bad. Completely ignoring my e-mails, not giving me photos that were taken, nor scans or moulds.