Hello, as per your description it seems to be some problem regarding jaw joints.. as you stated your doc was convinced that the pain is not from cavity in tooth that side..causes of pain includes your joint related muscles are having acute spasm, your articular disc is grinding against neuro bundles on movement of joint, trauma to joint..
please consult an ENT surgeon for ear problem as it may also cause inflammation in joint..
meanwhile- i advise you to have soft diet
, restrict your mouth opening to smaller extent, have some muscle relaxants and anti-inflammatory meds.. do hot fomentation of joints and its related muscles..
apply muscle relaxant gel on muscles of jaws..
if your pain doesnt subside in next 7 days, then few radiographs- TMJ
open n closed are required and you need to consult oral medicine specialist for further treatment.. he may advise you soft night guards to prevent trauma to joint , or give irrigation to joint for reducing inflammmation..