Can tmj pain start at any time? saw dds in apr. for exam had no problems. now pain when opening mouth but also swollen lymph nodes in neck.

Definitely: Tmj (disorder) can occur at anytime and can come and go with periods of stress or difference in routine. Swollen lymph nodes are not commonly associated and i would go back for a quick check up in case it's actually something else.

TMJ Onset: Tmj pain can have a sudden onset, but is usually precipitated by an event if it is sudden. The fact that you also have some lymphadenopathy leads me to believe that you have a possible infection that can give you some pain with mandibular movement. Ear infection? Wisdom teeth? Dental abscess even though recent visit (there could have been an occult abscess brewing that was not clinically seen).

Yes: Tmd can be precipitated by a specific event that traumatizes the joint(s) or it can develop slyly over time. The fact that it is of relatively recent onset suggests it may be easier to treat than had it been going on for a long time. Get to a tmd - aware dentist for an evaluation.

Yes, but: Yes, but don't get swollen lymph nodes from TMJ. See an oral surgeon or ENT doc to evaluate the lymph nodes.