ouch-ear-pain: i'd suggest starting a new topic along the lines of "anyone know of a good [neuromuscular] dentist in california?" or something, so that others will be specifically aware of your quest.
a nightguard is typically only worn at night time in the hopes of reducing the effects of grinding and/or stopping the grinding. of course, controversy exists on if they work or not.
a splint is worn 24/7 and can either be a stablizing or repositional. neuromuscular dentists tend to use repositional splints if there isnt enough space between the condyle and fossa. thus, it "repositions" the lower jaw by pulling it forward, in the hopes of getting a better occlusion, which should reduce the pain [if malocclusion is the cause of your problem].
to learn more about neuromuscular dentistry, try a search on the forum, since there are a whole lot more educated people who know way more than i do about neuromuscular dentistry.
[This message has been edited by saaraah (edited 09-14-2003).]