Why is it difficult to bite down after ortho spacers were put in (pre-braces). has my bite shifted? molars seem to touch more than before.

Bite has changed: The spacaers did move your teeth. That is why you have noticed a change. Your will notice that your bite will keep chaanging as you go thru your braces. At the end you bite will be stablized and your teeth will look and function great.

Teeth move and: The spacers put pressure on the teeth which causes them to move which in turn causes some inflammation around the periodontal ligament that surrounds the root of your tooth in your jawbone. When you bite down, the teeth are pushed against this sore area which causes the discomfort. Slight changes in your bite also occur. It's all temporary and normal.

Spacers/ Molar pain: It is very normal and typical for your molars to be tender after placement of spacers. The spacers are actually moving your teeth ever so slightly to create room for the molar bands. Good question.

Typical: the spacers are pushing your teeth to create room for the orthodontist to fit bands around your back teeth. A bit of discomfort is to be expected, but it should be minimal and only for a few days.