Are there any disadvantages of not to letting baby have a pacifier? Like affect their brain development?

Never heard of that before...only read articles/comments online that it probably may affect the growing of teeth or may affect the speech. I told my mum but she told me back..u also on pacifier till 5...see u also ok. Well..I think really depends on individual. I have a hard time weaning my #1 off pacifier. So #2 I never give and he is ok. Well really depends on the needs of each baby.