There could be several reasons for this,please notice if you hear popping sound while opening your month.
The proper diagnosis can only be made with proper investigations.(C.T,X ray etc).
For this you need to visit a higher center having oral and maxillofacial speciality.
Don't panic this could only be a very minor problem and can be treated manually and with proper medications and excercises.
Please go ahead with a higher center just to be sure about this.Do consult a oral and maxillofacial surgeon having experience in TMJ surgery,ENT mostly wont be of much help.I hope this helps,wishing you good health.
Next Steps
Consult Oral medicine and radiology specialist,after a diagnosis is made they will themselves refer you to the concerned speciality.
Health Tips
eat lots and lots of liquids and fruits and apply cold pack near joint area.