Establishing a diagnosis involves examination, review of medical and dental history, clinical data analysis, and tests that are specific to your condition. Only a dentist can evaluate your signs and symptoms to establish a diagnosis.
Myalgia is generally easily diagnosed by pressing lightly on the temple areas, the cheek bones, and the large closing muscles ("masseter muscle") at the angle of the mandible. However, myalgia is generally a symptom of a bigger problem. The challenging part is to accurately diagnose its causes, and to rule out contributing diagnoses such as tooth or jaw joint pain.