Jaw clench, IMHO, is one sign that you didn't let the reaction run long enough. Tooth grinding and jaw clench are the same problem described in different terms. Originally I blamed high reaction temps for jaw clench, and high temps may help create byproducts that cause jaw clench. I later encountered the problem in some reactions that had not been done at what I consider a higher temp, and realized that jaw clench was generally associated with incomplete reactions-- reactions where a good portion of the pseudo or E was reduced to meth, but which had a good percentage of unreduced intermediates. This is dope that would have been much better if refluxed at least twelve more hours.
It wasn't until I converted to the LWR than the connection between jaw clench and incomplete reactions became apparent. Even with temps higher than I planned or wanted, I have never experienced jaw clench with dope from a completed long wet reflux that was started without a show of smoke and fast HI production. Conversely, I ALWAYS experience jaw clench if I do meth made with a short/hot/fast cook method popular in my area. It is a distinctive signature of dope made by the method. The dope will keep you awake, even if you have to do more of it than you want, but it invariably gives you jaw clench. Jaw clench in my experience isn't related to the strength of the dope on a dosage unit basis, as some "strong" dope gives you jaw clench, and some "weak" dope will do the same. My impression is that jaw clench is a side effect caused by an intermediate which will reduce to meth if the reaction completes.
You can get to a clenched jaw state by overdosing on an amphetamine; and you can get there from excessive nervousness and stress exacerbated by sleep deprivation. The jaw clench I refer to is the product of the dope, and sets in with fifteen minutes of ingestion; it continues until the drug is no longer effective. It isn't the meth that does it; if it were, my LWR dope would cause it, and it doesnt. If it were, desoxyn would cause it and it doesn't. It is found commonly in less-than-completely-reduced meth and this suggests to me that it is caused by an unreduced intermediate.
The tourette's syndrome type of uncontrolled tounge and mouth movements is also something I have seen and experienced many times. It is far more common among "cranksters" than with users of cleaner, better quality meth. I have experienced it with batches that were good, strong batches. I have not noticed it with LWR dope. It does not appear as commonly as jaw clench; it does occur by the batch; some cooks have dope that produces the symptoms frequently, but I am not familiar with any cook whose dope always produces the symptoms. The symptoms appear dose related and related to how long the person has been under the influence of that batch of dope.
The symptoms, at least in my experience, are frequently observed with overuse of the meth, and use of meth in very high doses, but does not seem to be dependent on the concurrent existence of a state of sleep deprivation. The symptoms appear at high doses or high levels use over a period of time, and are frequently noticed with people who are "tweaking," although "tweaking" may occur without these symptoms. The pattern of occurrence of the symptoms, my experience with them, and my observation of the experience of family members who obtained their meth from a cook whose meth was notorious for this effect suggest it is caused by a byproduct. It seems to be a toxic effect operating on the nerves that control the mouth and tongue. The problem can persist after prolonged use of products that produce it. I have known a couple of people who have been diagnosed with tourette's syndrom who now have these involuntary mouth and tongue movements independent of drug ingestion. The use of methamphetamine by both these individuals reproduces the symptoms almost immediately. In my opinion, the symptoms are probably the result of a neurotoxin by product whose effect is enhanced by the ingestion of methamphetamine. I have suspected that heat may play a part in the formation of the byproduct, but that is basically a guess on my part.
