Will shortening of front teeth cause jaw to move side to side if it was previously held in place with long 2 front teeth overlapping bottom teeth. tmj?

Interdigitation: That is the term we use to describe how the teeth meet when the mouth is closed. If you have an overbite due to longer than usual central incisors, it may keep your jaw from moving into excursions freely, thus causing some TMJ symptoms.

Not necessarily: Not necessarily. Not everyone's jaws move side to side. Some people's jaw only move up and down, with minimal side to side movement. There needs to be some sort of abnormal muscle activity , like clenching or grinding, to lead to tmj. Talk to your dentist.

Long front teeth: In general, somewhat longer front incisors are preferred from a physiological standpoint. You should see a prosthodontist or other specialist who is skilled in occlusal (bite) therapy before shortening your incisors. Often occlusal/bite interferences on back teeth are responsible for preventing the jaw to easily move from side to side--not long front teeth.

Perhaps: Modifying certain teeth can cause the jaw to shift. Express your concerns to the dentist that did the work. Get a second opinion.