The opening of the mouth in the jaw joint is clinically known as joint popping. The main cause is the reversible anterior displacement of the joint disc of the temporomandibular joint. Due to the forward displacement of the joint disc, the condyles strike the posterior band of the joint disc during the opening, producing a popping sound. The process is painful in some patients, and most patients have no significant pain. For joint popping without obvious pain and dysfunction, it can be treated without special treatment, mainly by local protection, such as not opening the mouth wide, not eating hard things, and also by local heat application. Some of them can eliminate the joint popping, but if the effect is not good and there is no obvious pain or dysfunction, it can also be treated without treatment. Many joint popping may persist for a long time, but does not affect function.