Is it possible to evaluate tmj by touching and pressing jaws?

That is part, yes...: Temporomandibular joint pain can come from several possible sources. The joint capsule itself contains ligaments, tendons, and a cartilage disc. The surrounding muscles which facilitate movement are very often the source of pain secondary to clenching, grinding, or "bad bite" issues. This is something a dentist can and definitely should evaluate for you.

Not sure of question: If you tell someone about your symptoms, they see you and press on the TMJ to check for tenderness, they may be able to verify that you have TMJ syndrome---but really they have done a lot more than just press your jaw. It may be that all you notice is that pressing..

Somewhat: Palpating (feeling with fingers) the joints and muscles of the jaw is an important part of any TMJ exam. It provides valuable information on joint function or dysfunction, joint stability, and muscle tension. However, it should be combined with x-rays of the joints and teeth, as well as a full exam of the teeth.

TMJ Evaluation: An evaluation of the TMJ complex involves an examination of opening and closing your mouth, along with lateral movements of the jaw, palpation of muscles in and out of your mouth, palpation of both joints, listening for joint sounds, limits of jaw movements, deviations of opening and closing, and a comprehensive discussion of other possible symptoms. Imaging techniques may also be needed.

Yes: Yes, the TMJ evaluation relies a complete medical history, a complete physical exam (including the jaw and TMJ) and associated xrays, and sometimes other special studies. See a TMJ expert for advice.