Your question is totally unclear in its meaning. There could be two interpretations of this. If you are facing trouble opening your mouth, there could be a physiological reason for it. If you have always had trouble opening your mouth, then it is possible that you have some sort of fundamental problem in the bone structure of your face. The jaw bone, commonly known as the mandible, is the only joint on the face. It is also responsible for the amount to which you can open your mouth. For instance, if you cannot open your mouth too wide or too long, then you may be suffering from some sort of joint problem. Your best bet in this case is to get yourself examined by a doctor. It is always advisable to find out exactly what you are dealing with in such unusual matters. This is because there can be no home remedy available if you are facing a problem with a joint such as the mandible. You would also have to undergo treatment such as traction or regular physiotherapy. Sometimes, depending upon the severity of the situation, it is also possible that you may have to opt for something as serious as surgery. It is not possible to make such decisions without having a doctor examine your personally. This is not only inadvisable, it is also foolhardy.
The other interpretation of your question could possibly be that you figuratively have a lot of trouble opening your mouth. This would indicate that you are feel uneasy speaking. If this is the case, you must try to examine why this is so. A little bit of introspection will go a long way towards answering your question. If you are a shy person, then you will have to work dedicatedly to overcome this shyness and become a more confidant person.
You should bone up on your reading and general knowledge, which will give you more confidence when talking to others. It is also good to join some societies and classes that may be conducted in your residential area. There are usually public speaking classes held everywhere, and their sole aim is to help people gain confidence. before an audience or even a small group of people socially. You will be better equipped to open your mouth and talk.
answered by G M