Hello and welcome.
Thanks for writing your query.
problems may arise due to altered biting habits may lead to pain in front of ears. This makes mouth opening, biting and swallowing difficult.
Teeth grinding habit often alters the biting habit and leads to occlusal disharmony.
Exact diagnosis can be made only after clinical examination. So please visit a dentist
and get the evaluation done.
You may need an OPG radiograph done for you, which will help in ruling out the problem. Accordingly treatment can be planned.
Enlargement of lymph nodes in the neck is called as lymphadenopathy
and it is a sign of infection . yes it may be the result of tooth infection
spreading to underlying structures or it may arise due other health problems .
please get the examination done by a physician.
i hope this helps ,