Ouch. Being a guy, i guess i'll never know but it sounds painful!
Dangerous when. Teeth on a nursing child are only dangerous if you are not teaching your child not to clamp down. Otherwise most babies have already learned to use their upper lip and tongue as the suction makers and the teeth don't come into play. Best of luck though!
No difference. The way a baby latches to the breast, the tongue covers the teeth and you won't feel any difference. Some children, as the flow slows down at the end of the feeding, may slide off the nipple and bite. If you experience this, you can be proactive and take the baby off before that happens. Biting is not a normal part of breastfeeding and teeth rarely become and issue in the way it feels.
Breast feeding. It sounds to me more like it is time for real food along with milk in a glass (or breast milk in a glass or bottle).
Hurts!! Take the baby to the pediatric dentist. He/she can smooth the edges of the baby teeth so it won't be so traumatic.
Breast feeding. If your baby is over 6 months old, you'll find out soon . My wife breast fed both our girls and she was gently able to stop them from biting and she continued to breast feed for many more months.
Usually not harmful. Rarely painful, but it could be a problem if a real bite is experienced.
Watch out for biting. Breastfeeding should still be well tolerated but you may be faced with the occasional bite. If you say "no biting" and stop the feed immediately, most babies learn to stop biting.